AU2018212308B2

AU2018212308B2 - Sorbent composition and related system and method

Info

Publication number: AU2018212308B2
Application number: AU2018212308A
Authority: AU
Inventors: Christopher Francis Lucas; Nicholas John WALL
Original assignee: Ryan Francis Ltd
Current assignee: Ryan Francis Ltd
Priority date: 2017-01-26
Filing date: 2018-01-26
Publication date: 2023-11-23
Anticipated expiration: 2038-01-26
Also published as: WO2018139941A1; NZ755634A; AU2018212308A1

Abstract

The invention relates to a sorbent composition, and a related system and method for contaminant removal. In particular, the invention relates to a sorbent composition for removing one or more chemicals from a liquid, a system including both a sorbent composition and a container for containing the composition, and a method of applying the system to separate and/or remove one or more chemicals from a liquid, for example, from storm water, wastewater, and runoff. The sorbent composition preferably comprises activated charcoal and a non-swelling mineral having an anionic surface comprising hydroxyl groups, such as attapulgite and/or diatomaceous earth.

Description

SORBENT COMPOSITION AND RELATED SYSTEM AND METHOD

TECHNICAL FIELD

[0001] The present invention relates to a sorbent composition, and a related system and method. In

particular, the present invention relates to a sorbent composition for retaining one or more chemicals from a liquid, a system including both a sorbent composition and a container for containing the composition, and a method of applying the system to separate and/or remove one or more chemicals from a liquid.

BACKGROUND ART

[0002] In recent years, there has been a growing concern about the potential contamination of the storm water systems, especially as much of that water is untreated before entering natural water bodies such as rivers, lakes or even ground water systems.

[0003] Recent evidence has shown that the storm water systems are frequently contaminated with:

• metallic elements;

• compounds containing lead, mercury, asbestos, arsenic, iron, nickel, chromium;

• surfactants including cationic surfactants such as quarternary ammonium chlorides (QACs);

• disinfectants and cleaners; and

• organics such as benzene and polyaromatic hydrocarbons (PAHs).

[0004] One source of these contaminants entering the storm water systems is through roof drainage

systems, with the contaminants being present in roof run-offs as a result of:

• chemical compounds originally contained in the roofing material that have been leached out by rainwater (- it has been found that roofing materials can be major sources of copper, cadmium, zinc, arsenic and possibly PAHs and phthalates);

• coating or chemically treating rooftop material (- it has been a common practice that moss, mould and lichen on roofs are removed by regular spraying of the surface with dilute aqueous solutions of chemical blends involving a QAC such as dimethyl benzyl ammonium chloride (BAC)); and

• airborne contaminants that may be captured by falling rain (particularly in cities with poor air

quality).

[0005] In view of the above, mitigation strategies have been applied to roof run-offs by attempting to capture and dispose the run-offs off site, or to divert the roof run-offs from the storm water system. However, these all have limitations and drawbacks. [0006] Capture is often not possible because of the quantity of liquid involved, location and difficulty of accessing the capture points.

[0007] Diversion is also not likely because house owners are often opposed to having drainage pipes cut and diversion valves inserted to enable the roof run-off to be diverted away from the storm water system.

[0008] Thus, it is desirable to be able to capture or remove the chemicals from the roof run-offs, thereby preventing them from entering storm water systems in the first instance.

[0009] However, it is difficult to monitor the chemical levels and treat roof or storm run-offs since such water sources occur intermittently for short durations (e.g. run-offs from chemical treatment of rooftops). The run-offs also tend to be scattered at multiple sites and in open locations, adding onto the difficulty to monitor and treat such water sources.

[0010] Moreover, whilst there are a number of water purification technologies being developed to date, e.g. ion-exchange resins, reverse osmosis filtration membranes, distillation methods or sorbent material such as nanoparticles, these technologies often involve costly and sophisticated instrumentation and are often confined to applications inside fixed building premises (rather than in open locations). They also often only selectively target particular chemicals (or types of chemicals), and therefore may be inefficient to use with water sources that may contain a wide variety of chemicals.

[0011] Furthermore, there are rather limited water purification or filtration technologies available for treating storm water run-offs, especially for treating roof water run-offs so as to prevent chemicals from entering storm water systems in the first instance.

[0012] US 7918996 discloses a storm water filter bag assembly for filtering particles and sediments. The filter assembly comprises, inter alia, filter material being stitched together in a way to form at least two layers multiple parallel permeable tubes, with drain structures position in the creases between the tubes and a layer of bottom drainage structures located below the lowest layer of tubes. This filter bag assembly has a rather bulky and complex structure which would not at all be suitable for use within a much more confined roof drainage system. Moreover, the filter material of US 7918996 has filter openings of around 0.15 mm (or 150 μιη). Even dissolved natural organic matter (which are generally significantly larger in particle size than the metal or organic pollutants) found in environmental waters, are known to have a particle size distribution of < 0.1 μηι. Thus, the filter material of US 7918996 is not capable of removing the chemical pollutants from roof or storm runoffs. [0013] WO 2006084100 discloses a filtering system for containing, filtering or absorbing organics from contaminated waters. Within the system, there are two parallel absorption beds each containing a fluid-filtering/absorbing material, and a passage disposed between the absorption beds to enable an inflow of a contaminated water source. The contaminated water will then flow sideways through the absorption beds and be discharged through porous outer opposing side housing members, whilst the end housing member is non-porous. The filtering/absorbing material of WO 2006084100 is preferably in the form of imbiber polymeric beads which can imbibe the absorbed organics. Whilst WO 2006084100 discloses that the filtering system may be used to treat the organics in run-off from an impervious surface such as a paved street, parking slot or factory floor etcetera, the design of the filtering system (with the treated water being discharged sideways from the system) is impractical for use in a highly confined discharge system where water generally flows in a linear direction, e.g. in a roof drainage system. Also, the design of WO 2006084100 may only provide limited filtration efficacy since that the contaminated water generally only flows across the width of an absorption bed, with only a limited thickness of the absorption material being present. The filtration system of WO 2006084100 is also complex. It does not present a simple, economical and comprehensive solution for removing both organic and inorganic pollutants from contaminated waters.

[0014] AU 1997045210 discloses a sock type drain filter comprising a P.V.C. coated filter material shaped by the use of high frequency fabric welding so that it can be fitted into a stormwater gully by means of bolting a frame to a stormwater drain rim sandwiching the collar of the filter sock between them. The sock also includes an oil absorbent cushion filled with a hydrophobic polypropylene particles for removing oil contaminants. It can be seen that the sock of AU 1997045210 is rather specifically designed to be affixed to the rim of a stormwater drain, and to filter the water as it flows down the drain through the sock. The configuration of the sock is unsuitable for use with another drainage system, e.g. a roof drainage system where it is not possible to mount and hang the sock.

Furthermore, the filter materials used in this sock (i.e. the PV.C. coated filter material and the oil absorbent cushion) are only capable of picking up silt, rubbish and oil run-off, not the metal pollutants or cationic surfactants often found in a roof-drainage system.

[0015] NZ 518060 discloses a microbiological filter comprises apatite and a polymeric binder thereof and is in the form of a porous block or a sheet, for separating microorganisms from a fluid. NZ 518060 does not indicate whether the filter material (being a phosphate mineral) may also be used for separating chemical pollutants from a fluid. Furthermore, the rigid block design or the sheet design of the filter device would not suitable for use within a roof drainage system, particular considering that the opposing ends of the device need to be respectively fitted into a water supply conduit and a discharge conduit. This is impractical in a roof drainage system, where water would generally randomly flow down the rooftop, into a gutter and then discharged through a downpipe.

[0016] NZ 593756 discloses a biological filtration apparatus, for treating contaminated water, wherein the apparatus includes several socks having respective casings, with one or more pieces of biological filter material being tightly compressed within each casing. As contaminated water passes through the stack of socks, it is treated by both aerobic and anaerobic microbial action, with ammonium content of the water may be oxidised to nitrate by the aerobic action, then anaerobic treatment reduces the nitrate to, e.g. nitrogen gas. The filtration apparatus of NZ 593756 is bulky in structure and cannot be used within a confined roof drainage system (e.g. within gutters and downpipes). Also, the apparatus is complicated in design, costly to manufacture and only applicable to treat certain chemical contaminants. Thus, there remains a need to provide a simple, inexpensive water treatment option suitable for outdoor applications within confined drainage systems.

[0017] All references, including any patents or patent applications cited in this specification are hereby incorporated by reference. No admission is made that any reference constitutes prior art. The discussion of the references states what their authors assert, and the applicants reserve the right to challenge the accuracy and pertinency of the cited documents. It will be clearly understood that, although a number of prior art publications are referred to herein, this reference does not constitute an admission that any of these documents form part of the common general knowledge in the art, in New Zealand or in any other country.

[0018] Unless the context clearly requires otherwise, throughout the description and the claims, the words "comprise", "comprising", and the like, are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense, that is to say, in the sense of "including, but not limited to".

[0019] It is an object of the present invention to address the foregoing problems or at least to provide the public with a useful choice for removing one or more chemicals from liquids such as storm water systems and/or roof drainage systems.

[0020] Further aspects and advantages of the present invention will become apparent from the ensuing description which is given by way of example only.

DISCLOSURE OF THE INVENTION

[0021] In a first aspect the present invention relates to a sorbent composition for sorbing one or more chemicals from a liquid, the composition including

activated charcoal; and

at least one porous non-swelling mineral having an anionic surface comprising hydroxyl groups, and

a high specific surface area of at least 100 m²/g.

[0022] In a second aspect the present invention relates to a sorbent system for sorption of one or more chemicals from a liquid, the system comprising

a sorbent composition including activated charcoal and at least one porous non-swelling mineral having an anionic surface comprising hydroxyl groups and a high specific surface area of at least 100 m²/g, and

a container having an elongated body defining an inner cavity for holding the sorbent composition, the container formed from a porous material capable of retaining the sorbent composition therein;

wherein, in use, a body portion of the container holding the sorbent composition will have a volume that will result in at least 30% of the one or more chemicals in the liquid being sorbed.

[0023] In a third aspect the present invention relates to a method of removing one or more chemical contaminants from a liquid in a roof drainage system, the method including a step of

placing a sorbent system according to the second aspect of the present invention in a passage within the drainage system through which the liquid has to flow,

wherein at least a portion of the one or more chemical contaminants will be sorbed by the sorbent system as the liquid passes through.

[0024] In a fourth aspect the invention relates to a method of removing one or more chemical

contaminants from a liquid in a storm or surface water drainage system, the method including a step of

Mineral

[0025] Throughout the specification, the term "mineral" refers to a naturally occurring inorganic substance having a crystal (or an amorphous) structure. In certain embodiments the compositions and systems described herein include one or more minerals, all of which having sorptivity (i.e. capable of retaining one or more chemicals from a liquid by adsorption, absorption and/or ion exchange) due to properties including one or more of the following:

an anionic surface comprising free hydroxyl groups

a porous structure non-swelling

high specific surface area

[0026] Importantly, the one or more minerals useful herein not only has a porous structure, but also has a substantially consistent porosity or permeability, such that the mineral does not swell upon exposure to water, for example, nor do the particles flocculate or clump together, both of which leading to a loss of permeability.

[0027] The one or more minerals used herein in certain embodiments has a low bulk density, or voids in the mineral structure, in addition to or as a result of one or more of the above listed properties.

[0028] In one embodiment, the at least one mineral is selected from the group consisting of diamaceous earth, attapulgite, sepiolite and zeolite.

[0029] Diamaceous earth as used herein refers to a naturally occurring soft, siliceous sedimentary rock that is easily crumbled into a fine powder having a low density as a result of its high porosity.

Diatomaceous earth comprises fossilised remains of diatoms, a type of hard-shelled algae.

[0030] Attapulgite as used herein refers to a magnesium aluminium phyllosilicate, a specific type of

palygorskite which occurs in a type of clay soil mostly found in the Southeastern United States. This clay mineral has a needle-like non-swelling morphology as a result of its crystal structure.

[0031] Sepiolite as used herein refers to a magnesium silicate, a soft fibrous clay mineral having similar chemical properties to attapulgite. This mineral has low specific gravity and high porosity such that it may float upon water.

[0032] Zeolite as used herein refers to a family of microporous aluminosilicate minerals. There are over 40 naturally occurring zeolite minerals in the family. Some of the more common mineral zeolites are analcime, chabazite, clinoptilolite, heulandite, natrolite, phillipsite and stilbite. Zeolites have a porous structure that can accommodate a wide variety of cations.

Activated charcoal

[0033] Although the term "activated charcoal" is used throughout the specification, the substance is also known as 'activated carbon'. Thus, the two terms may be used interchangeably.

[0034] It should be noted that activated charcoal is charcoal that has been treated with oxygen resulting in a charcoal, or a form of carbon, that has millions of small, low-volume pores between the carbon atoms which increase the surface area available for adsorption or chemical reactions.

[0035] Without wishing to be bound by any particular theory, it is believed that activated charcoal mainly works by physisorption (or physical adsorption) due to Van der Waals forces which may create double layers on the treated surface active sites.

[0036] Activated charcoal is known to be effective for adsorbing, or trapping, other carbon-based

impurities (organic chemicals) as well as non-carbon based impurities such as chlorine.

Sorption

[0037] The term "sorption", "sorbing", "sorbency", "sorptivity", or variations thereof, as used herein refers to a physical or chemical process as a result of

absorption - the incorporation of a substance in one state into another of a different state, e.g. absorption of a chemical species in a liquid into a mineral of this invention;

adsorption - the physical adherence or bonding of ions and molecules onto the surface of another phase, e.g. adsorption of a chemical species in a liquid onto the surface of activated charcoal); and/or ion exchange - an exchange of ions between two electrolytes, e.g. zeolite may be considered a low cost ion-exchanger for sorption of heavy metal cations.

[0038] In the context of this invention, "sorption", "sorbing", "sorbency", "sorptivitiy", or variations thereof also implies that one or more chemicals from a liquid being retained by a sorbent composition of this invention by adsorption, absorption or ion exchange.

Chemicals

[0039] The terms "chemical" or "chemicals" as used herein refers to naturally occurring chemical

substances and/or those being distributed into the environment as a result of anthropogenic activities, and particularly in the context described herein includes one or more unwanted chemicals present in a liquid that desirably is to be removed.

[0040] The chemicals in the context used herein may be organic or inorganic chemical elements, chemical compounds, ions or solution species, and may exist in solid or liquid forms.

Specific surface area

[0041] Specific surface area as used herein refers to the total surface area of a solid, per unit of mass, and hence has a unit of measurement of m² / g (i.e. square-meter per gram). The solid may, for example, be a mineral according to this invention, or a sorbent composition according to this invention comprising activated charcoal and at least one mineral according to this invention.

Porous material

[0042] The term "porous material" as used herein refers to a porous, permeable material suitable for forming a container of the sorbent system described herein. The porous, permeable material enables a liquid containing one or more chemicals to flow through and yet is able to at least substantially retain the sorbent composition, i.e. substantially preventing particles of the composition from passing through the material.

[0043] In one embodiment, the porous material has a known-through plane water permeability, and a single sided calandered finish to retain the sorbent composition in use whilst allowing free controlled passage of water through the material.

[0044] In one embodiment, the porous material may be a porous, permeable and durable fabric, referred to herein as a geotextile fabric, suitable for outdoor use, particularly repeated/extended outdoor use.

[0045] In another embodiment, the porous material may be a disposable material, such as a disposable fabric, if the sorbent system is intended for a single use or limited use, for example.

Container

[0046] The term "container" as used herein refers to a container formed from the porous material

according to this invention.

[0047] The container may take various forms and shapes, e.g. as a bag, a sack, a box, a case, a tube, or a sock.

[0048] In one embodiment, the container has two opposing sides and two opposing ends.

[0049] In another embodiment, the container enables a liquid carrying one or more chemicals to pass through the porous material on one side or end of the container, to reach and be treated by a sorbent composition held within the container, then the treated liquid may exit the porous material on an opposing side or end of the container.

[0050] In one embodiment, the container is formed from a geotextile fabric, and is referred to herein as a geotextile container.

Roof drainage system

[0051] The term "roof drainage system" as used herein refers to a gutter and d rainpipe system, and the components therein, which carry water (e.g. run-off from a roof treatment or rain water) from a roof top down towards then away from the foundation of a house.

[0052] The roof drainage system includes, but not limited to, components such as gutters (or spouts), drop outlets (or droppers), downpipes and downspouts (or leaders), and headers.

[0053] In the context used herein, the term "gutter" refers to a horizontal channel installed along the edge of a roof to channel water away from the rooftop.

[0054] The term "downpipe" as used herein refers to a pipe which carries roof water from gutters and other roof catchments to drains or storage tanks. [0055] The term "drop outlet" or "dropper" as used herein refers to a formed piece or a short fitting that serves as an exit from which water can travel from the horizontal section of the gutter to a downpipe or leader.

[0056] The term "downspout" as used herein refers to any stretch of pipe that serves the purpose of

draining water from roof gutters.

[0057] The term "header" as used herein refers to a receptacle component, typically in fluid

communication with a dropper or downspout, that provides a volume, usually an increased volume, for liquid exiting a gutter system into a downpipe or liquid in a downpipe.

Storm water or surface water drainage system

[0058] The term "storm water or surface water drainage system" as used herein refers to a system

designed to drain excess rain water, or water from an anthropogenic source (e.g. carwashes), from impervious surfaces including paved streets, road surfaces, carparks, footpaths, sidewalks, residential driveways or paved areas around a residential house. The drainage system may include a plurality of manholes and/or water drainage points. The drainage system also includes the impervious surfaces leading to the manholes and/or water drainage points. In certain embodiments, the drainage system also contemplates systems to drain excess water from permeable surfaces, such as fields, pastures and the like, particularly in the context of managing excess water flow including surface water flow.

Passage

[0059] The term "passage" as used herein refers to any pathway through which a liquid containing one or more chemicals travels.

[0060] When the term is used in relation to the roof drainage system, "passage" may refer to any section or component of the roof drainage system, including any gutter, drop outlet, downpipe or downspout, or header component or section through which contaminated roof water travels through. The term "passage" in this instance may also refer to a pathway, a section, or a distance between an exit of the roof drainage system and a drainage point on the ground through which the roof run-off may be diverted into a ground drainage system.

[0061] When the term is used in relation to a storm water or surface water drainage system, "passage" may refer to a pathway, a section or a distance through which the liquid (which may be rain water, storm water or any surface run-off) travels from a source to a drainage point. The term "passage" may also refer to any section or component within a storm water or surface water drainage system, including a drainage point through which the liquid flows from an external environment into the storm water or surface water drainage system. DETAILED DESCRIPTION OF EMBODIMENTS

Sorbent Composition

[0062] In one embodiment, the at least one mineral has a high specific surface area of at least 100 m²/g.

For example, the mineral according to the present invention has a high specific surface area of at least 120 m²/g, at least 150 m²/g, at least 175 m²/g, at least 200 m /g, at least 220 m²/g or at least 240 m²/g.

[0063] In one embodiment, the at least one mineral has a high specific surface area of in the range of 175 - 400 m²/g. In one embodiment, the at least one mineral has a high specific surface area in the range of 175 - 350 m²/g, or for example 200 - 300 m²/g.

[0064] In one embodiment, the sorbent composition comprises activated charcoal and one or more

minerals selected from the group consisting of of diamaceous earth, attapulgite, sepiolite and zeolite.

[0065] It should be noted that the ingredient(s) of the sorbent composition, individually or collectively (e.g. a mineral of this invention and/or activated charcoal), may be referred to as a sorbent.

[0066] In one embodiment, the activated charcoal is contiguously dispersed in the one or more minerals of the sorbent composition.

[0067] In one embodiment, the activated charcoal comprises fine particles that are contiguously and/or substantially evenly distributed within particles of the one or more minerals.

[0068] In one embodiment, the activated charcoal comprises fine particles that are dispersed and

contained within pores or structures of the one or more minerals.

[0069] Advantageously, embodiments of the sorbent compositions described herein have a high specific surface area for sorption of one or more chemicals from a liquid. In one embodiment, the sorbent composition has a high specific surface area of at least 120 m²/g, for example, at least 150 m²/g, at least 175 m²/g, at least 200 m²/g, at least 220 m²/g, at least 240 m²/g, at least 260 m²/g, at least 280 m²/g, at least 300 m²/g, at least 320 m²/g, at least 340 m²/g, at least 360 m²/g, at least 380 m²/g or at least 400 m²/g.

[0070] In one embodiment, the sorbent composition has a high specific surface area in the range of 150 - 600 m²/g, for example, in the range of 150 - 500 m²/g, such as in the range of 175 - 400 m²/g.

[0071] In another embodiment, the sorbent composition has a high specific surface area in the range of 200 - 300 m²/g.

[0072] Advantageously, as the mineral(s) and activated charcoal in the sorbent composition may exhibit different physical and/or chemical properties, they may have different efficacies for sorption of inorganic and organic chemical species from a liquid. For example, the negatively charged mineral surface may render the minerals more suitable for sorption of metal ions or charged solution species, whilst activated carbon will generally selectively sorb organic or neutral solution species. Thus, the combination of at least one mineral, e.g. diamecous earth, attaulgite, or both, with activated carbon is advantageous in that the resultant sorbent composition will exhibit efficacy for sorbing a wide range of organic and inorganic chemicals from a liquid, such as a water source contaminated with a plurality of chemicals.

[0073] In one embodiment, the sorbent combination includes a combination of two or more minerals, e.g. diameceous earth or attapulgite with zeolite, since a mineral such as attapulgite is capable of sorbing oil and grease whilst zeolite is capable of sorbing heavy metal cations (such as cations of Pb, Cu, Cd, Zn, Co, Cr, Mn and Fe).

[0074] Thus, depending on the chemicals to be targeted, sorbent compositions of certain embodiments contain various combinations of one or more minerals and activated charcoal, for selective sorption of inorganic and/or organic chemicals from a contaminated liquid.

[0075] Advantageously also, in various embodiments, various ratio ranges of mineral(s) and activated charcoal are adopted for greater sorptivity, or selective sorption, of one or more types of chemical.

[0076] In one embodiment, the sorbent composition comprises the following combination of ingredients at the weight % ranges as shown:

Attapulgite 50 - 80 wt%

Diatomaceous Earth 20 - 30 wt%

Activated Charcoal 5 - 15 wt%

[0077] Attapulgite is a hydrated, octahedrally layered acicular magnesium aluminium silicate with a large number of -OH (hydroxyl) groups on its surface, being able to bind cationic species from solution. Advantageously, the long axis of the attapulgite crystals extends in the same direction as the submicron channels, which provides a rather large surface area for reaction and absorbency.

Furthermore, attapulgite derives its non-swelling needle-like morphology from its three-dimensional crystal structure. The shape and size of the needles also endow attapulgite with unique properties such as non-swelling, high surface area and high porosity.

[0078] In one embodiment, the attapulgite in the sorbent composition has high specific surface area in the range of 150 - 350 m²/g, for example 175 - 330 m²/g.

[0079] In another embodiment, the attapulgite in the sorbent composition has the following properties:

specific surface area in the range of 200 - 300 m²/g oil retention value in the range of 20 -30%, e.g. 25%

cationic exchange capacity 0.2 - 0.4 mq/gm, e.g. 0.3 mq/gm

[0080] Diatomaceous earth also has hydroxyl groups on the mineral surface for binding cations and

provides a large surface area for sorption. In addition, diatomaceous earth is a highly porous silica containing exchangeable sodium, magnesium and iron (and hence ion-exchange may be one of the mechanisms that diatomaceous earth may sorb cationic species from a liquid). Advantageously, diatomaceous earth has a non-swelling structure and rather low bulk density, rendering it highly suitable as a sorbent material.

[0081] Advantageously, due to high degree of microporosity, activated charcoal also provides high specific surface area for sorption of organic or gaseous species in particular.

[0082] In one embodiment, the activated charcoal in the sorbent composition has high specific surface area in the range of 200 - 400 m²/g, for example 250 - 350 m²/g.

[0083] In another embodiment, the activated charcoal in the sorbent composition has the following

properties:

specific surface area in the range of 280 - 320 m²/g, e.g. 300 m²/g particle size less than 10 μιη, e.g. less than 8 μηη, less than 5 μηη

[0084] In one embodiment of the sorbent composition, the activated charcoal having the above-mentioned properties is contiguously dispersed in the one or more minerals. For example, the activated charcoal is contiguously dispersed in diatomaceous earth and/or attapulgite.

[0085] Advantageously, a sorption composition comprising attapulgite, diatomaceous earth and activated charcoal is believed, without wishing to be bound by any theory, to create a uniquely large surface area for sorption of inorganic and organic chemical species from a liquid. This is at least one of the outstanding advantages of this invention.

[0086] It should be noted that the mineral(s) and/or activated charcoal for forming the sorbent

composition may be in a variety of forms, e.g. as powders, particles, granules, pellets or in extruded forms.

[0087] In one embodiment, a sorbent composition further comprises a pack filler material (e.g. to bulk up the volume of the sorbent composition) and/or a material with water retention properties. Such a material itself may also exhibit some level of sorptivity for the one or more chemicals in the liquid. Examples of such material may include wood chips or saw dust.

[0088] In one embodiment, the sorbent composition further comprises a water retention material. For example, the water retention material may be a hydrogel based on a mineral according to this invention, e.g. a hydrogel based on attapulgite.

[0089] Advantageously, the sorbent compositions will in certain embodiments be used for both recovery and/or removal of one or more chemicals from a liquid.

Sorbent System

[0090] In one embodiment, the sorbent system is for sorption of one or more chemicals from a liquid runoff from the chemical treatment of roofs, wherein, in use, a body portion of the container holding the sorbent composition will have a volume that will result in at least 30% of the one or more chemicals in the liquid run-off being sorbed.

[0091] In another embodiment, the sorbent system is for sorption of one or more chemicals from a liquid run-off in a storm or surface water drainage system wherein, in use, a body portion of the container holding the sorbent composition will have a volume that will result in at least 30% of the one or more chemicals in the liquid run-off being sorbed.

[0092] In one embodiment, the elongated body portion of the container having an in inner cavity for holding the sorbent composition has:

an openable end for receiving the sorbent composition, and

a sealed end to secure the sorbent composition within the inner cavity.

[0093] With the openable end design, the sorbent composition held within the inner cavity may be disposed after one or more uses, and replaced with a quantity of fresh sorbent composition as required.

[0094] Advantageously, the openable end design also enables the quantity of the sorbent composition to be adjusted during a single use or between repeated uses of the sorbent system depending on the concentration of the pollutants or quantity of water to be treated, for example. The openable end design enables additional quantity of the sorbent composition to be added into the container, or excess quantity removed, as required.

[0095] In another embodiment, e.g. for a disposable version of the container or the sorbent system, the body portion of the container may have both ends sealed, thereby forming a fully enclosed container. Thus, as the sorption composition held within the container becomes saturated with chemicals, the container or the sorbent system may then be disposed.

[0096] In one embodiment, the porous material for forming the container has a porosity in the range of 20 - 90 μηη, a tensile strength in the range of 6 - 15 N/m² and a thickness in the range of 1 - 10 mm. [0097] The physical parameters of the porous material may also vary depending on the quantity (weight) and specific ingredients of the sorbent combination to be placed inside the container.

[0098] In one embodiment, the porous material for forming the container is a geotextile fabric, thereby giving rise to a geotextile container.

[0099] In one embodiment, the geotextile fabric for forming the container of this invention is made from a polypropylene, polyester, polyurethane or other similar synthetic polymeric material in woven, needle punched or needle felt, or heat bonded form.

[00100] In one embodiment, the geotextile fabric for forming the container has the following general physical properties:

Base material Polyester

Tensile Strength 9 kN/m²

Burst Strength 6.4 kN/m²

Thickness 1.4—1.6 mm

Average pore size 50pm

Transplanar transmissivity 6L per minute

Crossplanar transmissivity 3.4L per minute

[00101]The geotextile fabric of one embodiment has a single sided calendared finish.

[00102] In one embodiment, the geotextile fabric is sufficiently durable for repeated outdoor use of the geotextile container, if required. In this instance, the tensile strength of the fabric of certain embodiments is at least 6 kN/m², the burst strength is at least 3 kN/m² and the thickness of the fabric is in the range of 1.1 - 8 mm.

[00103]The physical parameters of the geotextile fabric may also vary depending on the quantity (weight) and specific ingredients of the sorbent combination to be placed inside the geotextile container.

[00104] In one embodiment, the geotextile container in the sorbent system is formed from a porous

polyester needlefelt fabric.

[00105] ln one embodiment, the container takes a substantially elongated sock or tube design, having a body length in the range of 20 cm - 300 cm and a width of 3 - 50 cm.

[00106]The above will provide a container volume in the range of 140 - 550000 cm³ for holding the sorbent composition. [00107] ln one embodiment, the weight of sorbent composition for filling the container falls in the range of 100 - 5000 g (grams). For example, the weight of the sorbent composition for filing the container falls in the range of 200 - 4000 g, 200 - 3000 g, 300 - 3000 g, 300 - 2000 g, 300 - 1500 g, 500 - 2500, or 500 - 1500 g.

[00108] ln one embodiment, the body portion of the filled container takes a substantially tubular shape. In this instance, the sorbent composition may form a packed column within the body portion, with the column extending in the same longitudinal axial direction of the container.

[00109] In one embodiment, the body portion of the container will contain sufficient sorbent composition to result in at least 30% of the one or more chemicals in a liquid being sorbed. For example, the body portion of the container will contain sufficient sorbent composition to result in at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, or at least 95%, of the one or more chemicals in the liquid being sorbed.

[00110] ln one embodiment, the body portion of the container holding the sorbent composition has a volume that will result in at least 30% of the one or more chemicals in a liquid being sorbed. For example, the body portion of the container holding the sorbent composition has a volume that will result in at least 50%, 60%, at least 70%, at least 80%, at least 90%, or at least 95%, of the one or more chemical in the liquid being sorbed.

[00111]Advantageously, in one embodiment in which the container has an openable end, more sorbent composition may be added into the container as the sorbency level of the sorbent composition decreases upon use.

[00112] In one embodiment in which the container is formed from a geotextile fabric, the body portion of the geotextile container holding the sorbent composition has a length in the range of 20 - 300 cm, and a cross-sectional diameter in the range of 3 - 50 cm.

[00113] ln one embodiment, the body portion of the geotextile container holding the sorbent composition has a length in the range of 50 - 200 cm, and a cross-sectional diameter in the range of 5 - 40 cm.

[00114] ln one embodiment, the body portion of the geotextile container holding the sorbent composition has a length in the range of 80 - 150 cm, and a cross-sectional diameter in the range of 7 - 30 cm.

[00115] ln another embodiment, the body portion of the geotextile container holding the sorbent composition has a length in the range of 90 - 110 cm, and a cross-sectional diameter in the range of 8 - 12 cm. [00116] ln one embodiment, the body portion of the geotextile container holding the sorbent composition has a length in the range of 30 - 100 cm, and a cross-section diameter in the range of 5 - 15 cm. In this instance, the body portion holding the sorbent composition has a volume in the range of 550 - 18000 cm³ which will result in at least 30% or at least 50% of the one or more chemicals in the liquid being sorbed.

[00117] ln one embodiment, the body portion of the container holding the sorbent composition has

a) a length from about 50 cm to about 150 cm,

b) a length from about 70 cm to about 120 cm,

c) a length from about 80 cm to about 105 cm,

d) a length from about 90 cm to about 100 cm,

e) a cross-sectional diameter from about 6 cm to about 20 cm,

f) a cross-sectional diameter from about 7 cm to about 15 cm,

g) a cross-sectional diameter from about 8 cm to about 12 cm,

h) a cross-sectional diameter from about 9 cm to about 10 cm, or

i) any combination of one of a) to d) and one of e) to h).

[00118] ln one embodiment, the volume of sorbent composition present is

a) from about 2000 cm³ to about 7000 cm³,

b) from about 2500 cm³ to about 6800 cm³,

c) from about 2500 cm³ to about 6200 cm³,

d) from about 2500 cm³ to about 6000 cm³,

e) from about 2500 cm³ to about 5800 cm³,

f) from about 3000 cm³ to about 6800 cm³,

g) from about 3000 cm³ to about 6200 cm³,

h) from about 3000 cm³ to about 6000 cm³,

i) from about 3000 cm³ to about 5800 cm³,

j) from about 3500 cm³ to about 6800 cm³,

k) from about 3500 cm³ to about 6200 cm³,

1) from about 3500 cm³ to about 6000 cm³,

m) from about 3500 cm³ to about 5800 cm³,

n) from about 4500 cm³ to about 6800 cm³;

o) from about 4500 cm³ to about 6200 cm³;

P) from about 4500 cm³ to about 6000 cm³; or

q) from about 4500 cm³ to about 5800 cm³. [00119] ln another embodiment, the dimension (i.e. length, cross-sectional diameter and/or volume) of the filled geotextile container is such that the body portion of the geotextile container holding the sorbent composition has a length that will result in at least 30% sorptivity. In one embodiment, the length is such that it will result in at least 50%, 60%, 70%, 80%, 90% or 95% sorptivity of the one or more chemicals in the liquid.

[00120]Advantageously, the container of this invention (geotextile or non-geotextile) can be filled to a dimension such that the end sorbent system substantially conforms with the dimension of a receiving site (e.g. the length, width and height of a gutter, or the diameter of a downpipe or a drench leading to a storm drain).

[00121]Therefore, in one embodiment, the body portion of the container (geotextile or non-geotextile) holding the sorbent composition has a length in the range of 30 - 200 cm, and a cross-sectional diameter in the range of 5 - 25 cm for placing in a roof drainage system such as a gutter. For example, the body portion of the container holding the sorbent composition has a length in the range of 50 - 150 cm, 70 - 120 cm, 80 - 105 cm, or 90 - 100 cm, and a cross-sectional diameter in the range of 6 - 20 cm, 7 - 15 cm, 8 - 12 cm, or 9 - 10 cm, for placing in a standard gutter system.

[00122]Advantageously also, the container or the sorbent system of this invention may be shaped or configured to conform to the shape or dimension of a receiving site, for the purpose of, e.g., blocking a passage through which liquid flows, e.g. in a gutter adjacent to a drop outlet, inside a drop outlet or a downpipe.

[00123] ln another embodiment, a sorbent system according to this invention may be placed near, at or just outside a drainage point on the ground, to filter a liquid run-off discharged from a downpipe or an exit of a roof drainage system, or a run-off from a paved surface (e.g. a road, driveway or carpark).

[00124]Advantageously, a sorbent system according to the present invention may be placed internally or externally along any passage through which a liquid run-off travels.

[00125]Advantageously also, one or more sorbent systems may be placed within a passage, or around a drainage point, through which a contaminated liquid flows, in order to provide maximum filtering capacity.

[00126] ln one embodiment where application to a mass area is required, a plurality of sorbent systems according to the present invention may be applied simultaneously in various ways. For example, in the embodiment in which the container is a geotextile container, a plurality of sorbent systems according to this invention may be bundled or stacked together, then placed inside one large (empty) geotextile container, or even inside a milk crate. [00127] In another embodiment, a plurality of the sorbent systems according to the present invention may be assembled or fastened together, and applied as an assembly for maximum efficiency and/or to provide a

staggered or step-wise filtration system.

BRIEF DESCRIPTION OF DRAWINGS

[00128] Further aspects of the present invention will become apparent from the following description which is given by way of example only and with reference to the accompanying drawings in which:

Figure 1 is a perspective view of a container according to this invention with the container in an open position;

Figure 2 is a perspective view of an opposing side of the container of Figure 1;

Figure 3 is a perspective view of the container of Figure 1 in a closed/sealed position;

Figure 4 is a top plan view of two sorbent systems according to this invention in use inside a gutter; and

Figure 5 is a perspective view of a sorbent systems according to this position in use inside a gutter; BEST MODES FOR CARRYING OUT THE INVENTION

[00129] Referring to Figure 1, there is provided a container 10 according to this invention.

[00130]The container 10 is in one embodiment formed from a geotextile fabric, and hence in the form of a geotextile container. The container 10, however, may be a non-geotextile (e.g. a disposable) porous material according to this invention.

[00131]The container 10 has an elongated body portion 12, which takes a substantially tubular shape.

[00132]The body portion 12 has two opposing sides 14a and 14b, and two opposing ends 16a and 16b. The container 10 is formed by stitching and overlocking the porous material (e.g. a geotextile fabric): along an elongated side 14a, and

across an end 16a, thus forming a fully sealed end of the container 10.

[00133]The free, unstitched elongated side 14b allows the container 10 to expand (or open up) to form a tubular shape relative to the fixed, stitched side 14a, particularly when the container is being filled with a sorbent composition according to this invention.

[00134]The container 10 also has a free, unstitched end 16b, which serves as an opening to an inner cavity 17 disposed within the container 10, for receiving a sorbent composition.

[00135] Referring to Figures 1 and 2, the container 10 has two opposing external side surfaces 18a and 18b (with the inner cavity 17 spanning therebetween). On surface 18a, disposed adjacent, yet a distance away from, the end 16b of the container, there is provided a first fastening means in the form of a piece of hook and pile fastening (such as that sold under the trade mark Velcro) 20a. On surface 18b, disposed right against an edge of the end 16b, there is provided a second fastening means in the form of a piece of Velcro 20b, the two pieces of Velcro 20a and 20b being substantially the same size.

[00136] eferring to Figure 3, the two pieces of Velcro are positioned such that, the second piece of Velcro 20b along with an end section of surface 18b may fold backwards until Velcro 20b is disposed directly above Velcro 20a, to thereby enable the Velcro to engage one another. In so doing, when the two pieces of Velcros are firmly engaged, it forms a scroll structure 22 as shown in Figure 3. In use, the scroll structure 22 presents the sorbent composition contained within the inner cavity 17 from falling out.

[00137]Advantageously, fastening means such as the two pieces of Velcro 20a and 20b, provides the container 10 with an openable/closable end 16b. This in turn provides a flexible sorbent system according to this invention, wherein the sorbent composition may be disposed (or partially disposed), have additional quantity added or be entirely replaced as required, thereby enabling single use or repeated use of the sorbent system as desired.

[00138]Whilst the container 10 uses Velcro pieces 20a and 20b as the fastening means, other forms of fastenings means, e.g. a plastic zip extending along the width of the end 16b, may be used to provide an openable/closable container according to this invention. In a single use system, the container, once filled with the sorbent composition, may have both ends stitched to form two sealed ends.

[00139] Referring to Figure 4, there is shown two sorbent systems 100a & 100b of this invention in use in a roof drainage system, to treat a liquid run-off from a chemical treatment of the roof.

[00140] In this particular embodiment, the two sorbent systems 100a and 100b according to this invention are placed inside a gutter 102. In particular, the sorbent systems 100a and 100b are placed near an opening 104 in the gutter. The opening 104 is typically fitted with a gutter dropper (or drop outlet), then the dropper being connected to a downpipe, which directs the roof run-off towards and away from the foundation of a house.

[00141]The sorbent systems 100a and 100b each include a container 10 of a chosen dimension (e.g.

approximately 100mm in length and 9.5 mm in width), and the container 10 is filled with a sufficient volume of the sorbent composition (e.g a volume in the range of 2000 - 7000 cm³, for example 2500 - 6800 cm³, 3000 - 6200 cm³, or 3500 - 6000 cm³, such as 4500 - 5800 cm³ ), such that the sorbent systems 100a and 100b each has a dimension that substantially conforms to the dimension of a standard gutter, as shown in the top plan view of Figure 4.

[00142] With the respective dimension of the sorbent systems 100a and 100b providing a close (or in one embodiment a tight) fit within the gutter 102, each sorbent system is able to create a 'dam effect' after it is place inside the gutter 102. Take the sorbent system 100a as an example, the system 100a is able to (substantially) block off the flow of a contaminated liquid in a linear direction along the length of the gutter 102, towards the gutter opening 104.

[00143]With the placement of the sorbent system 100a in the gutter as shown in Figure 4, the

contaminated liquid run-off will have to enter the sorbent system 100a from one end of the container 10, move through the sorbent composition along the length of the container 10, then the treated liquid may exit from an opposing end of the container 10 and flow towards the gutter opening 104.

[00144]With the container 10 being formed of a porous material (in one embodiment a geotextile fabric) with known-through plane water permeability and a single sided calandered finish, the liquid run-off carrying the chemical pollutants is able to freely flow pass the fabric layer, to come into contact with the sorbent composition contained inside the container 10. With the sorptivity endowed by the sorbent composition of this invention, at least a portion of the one or more chemical contaminants will be sorbed by the sorbent system as the liquid gradually flows through the sorbent system.

[00145]The placement of the sorbent system 100a within the gutter 102 is such that, as the contaminated liquid flows through, it is actually travelling through a column (in this instance held in a horizontal position) of sorbent composition. In one embodiment, the sorbent system 100a will contain a sufficient volume of sorbent composition such that the contaminated liquid will flow through a column of sorbent composition of at least 60 cm in length (or the body portion of the container holding the sorbent composition will have a volume of at least 2000 cm³), which length (or volume) is sufficient to remove at least 30% of the one or more chemicals contained in the liquid run-off.

[00146] In one embodiment, at least 50%, 60%, 70%, 80%, 90% or 95% of the one or more chemicals in the liquid will be removed when the contaminated liquid travels through the volume, or length, of the sorbent composition inside the sorbent system.

[00147] In one preferred embodiment, the body portion of the sorbent system 100a holding the sorbent composition will have a length in the range of 80 - 95 mm (or a volume in the range of 4000 - 6100 cm³) for removing at least 90% of the one or more chemicals contained in the liquid run-off.

[00148] Advantageously, the volume of the sorbent composition, and hence the length of the column, can be easily varied (particularly with the openable/closable end design of the container of the present invention) according to a particular situation or requirement, e.g. when the chemical levels in the roof run-off are expected to be high, then a larger volume, or longer column, may be put in place to remove a substantial portion of the chemicals from the contaminated liquid.

[00149] In the embodiment of the invention shown in Figure 3, the sorbent systems 100a and 100b are orientated such that the sealed end 16a is positioned proximal to the gutter opening 104, whilst the openable/closable end 16b is positioned distal to the gutter opening 104. It should be noted that the sorbent systems may also be positioned in an opposite orientation without affecting the performance of the sorbent systems (since the geotextile fabric of this invention is sufficiently porous to enable free flow of the contaminated liquid from either end of the container into the cavity holding the sorbent composition).

[00150]Also, whilst the embodiment shown in Figure 3 depicts two sorbent systems 100a and 100b, in use, one or more sorbent systems may be placed inside the roof drainage system depending on factors such as the configuration of the gutter system, the number of gutter drop outlets therein, and/or the volume of contaminated liquid etcetera.

[00151] Referring to Figure 4, there is shown a sorbent system 200 of this invention in use in a roof drainage system, to treat a contaminated liquid run-off. In this embodiment, an openable/closable end of the container, with the scroll structure 202, is placed inside the gutter 204, proximal to the gutter opening 206 leading to the downpipe 208.

[00152] In another embodiment, of the invention, the sorbent system 200, or a further sorbent system according to this invention, may be placed inside the downpipe 208. The dimension of the sorbent system 200 is that it will snuggly fit inside the downpipe 208, and the friction between the two opposing external side surfaces of the container and the inner wall of the downpipe 208 may suspend and maintain the sorbent system in position.

[00153]The sorbent system may also be held in position by a gutter droplet with a cone shaped section (not shown in Figure 4) connecting the gutter opening 206 to the downpipe 208.

[00154] In the above instances, the contaminated liquid may be treated as it travels in a downward

direction, through a column of a sorbent composition contained within the container of this invention.

[00155]Whilst Figures 1-4 exemplify ways that one or more sorbent system of this invention may be used inside a roof drainage system to treat a contaminated liquid run-off, it should be noted that one or more sorbent systems of this invention may also be used to treat a contaminated storm water source. In this instance, for example, one or more of the sorbent systems of this invention may be placed along or across a drench (through which a contaminated road run-off has to flow) leading to a storm water drain, to thereby treat the road run-off before it enters the storm drainage system.

[00156] Also, in situations where the sorbent system of this invention is intended for multiple uses, the system may be removed from the gutter after each use (e.g. after a chemical treatment of the roof and when the contaminated liquid has been thoroughly filtered), and conveniently stored for its next use.

[00157]Advantageously, in a situation involving a large quantity of contaminated liquid and/or a large contaminated area, a plurality of sorbent systems (such as 100a, 100b or 200) may be used simultaneously. In this instance, the sorbent systems may simply be stacked vertically as a pile, or stacked together horizontally. The sorbent systems may also be placed inside a large container 10, for example. In another embodiment, the sorbent systems may be fastened together, e.g. using Velcro strips.

Examples

Example 1 - Geotextile Fabric

[00158] In this example, the geotextile fabric for making a geotextile container according to this invention has the following physical properties

Base material Polyester needlefelt.

Tensile Strength 9kN/m²

Burst Strength 6.4kN/m²

Thickness 1.4—1.6 mm

Finish Single sided calendared finish

Average pore size 50μιη

Transplanar transmissivity 6L per minute

Crossplanar transmissivity 3.4L per minute

[00159]This combination of properties of the fabric has been found to contain the particles of a sorbent composition according to this invention particularly well. The fabric is robust enough for regular repeated use, allows free passage of water through the fabric and into the contained sorbents and does not contain potential leachates.

Example 2 - A target chemical to be detected [00160] It has been known that QACs are frequently found in the run off during typical roof cleaning. In this example, a study was carried out to provide a baseline quantification of the extent of the QAC contamination.

[00161]Samples were taken over a year long season of roof cleaning of a variety of substrates, roof types, locations and contaminants; these varied from large scale coastal industrial facilities, through to urban domestic long run. Additional work was also conducted on a laboratory scale on old roofing materials, where the cleaning solution was run down a 2m length of contaminated material and the run off collected and analyzed— both initially and after a period of time to mimic rainfall within a period that it might be expected that QAC activity was still high enough to be of concern.

[00162]The analytical method of choice for this stage was HPLC allied to ESI- tandem mass spectroscopy and all results given have used this method of analysis.

Levels of QACs in run off.

[00163]The wash off was done by applying the equivalent of 2mm of rainfall by spray and collecting the last 50ml drain off from the area as it entered the gutter system.

[00164]The concentrate is diluted at a rate of 5L per 400L of water to give a slightly higher than 1% solution of the Sythequat LF for use on site. A typical application rate is 1L per square metre, thus a typical domestic roof of 250 actual roof area (allowing for corrugation effects), would utilize approximately 250L during cleaning. The published literature indicates an almost immediate decrease in activity of 90% during use and thus it might be expected that each house could contribute approximately 156g of excess QAC during a cleaning operation. Assuming that this is contained within the original 250L of water the concentration would be 0.63g/L as a maximum. This does not allow for any absorbance from detritus and debris contained within the gutters and spouting.

[00165]Table 1 below presents the results of washdown on a number of roofs of different composition, with and without moss and/or lichen present.

Table 1 - Washdown results

[00166]These results show that rainfall 24 hours after a roof has been cleaned with the BAC product the amount washing off the roof is significantly below the amount washing off initially. These wash off levels after 24 hours are a worst case scenario and do not take into account any absorption within either the guttering or storm water system. Significantly these levels are below the EPA fish toxicity and indicate that once the roof has been cleaned it is unlikely to release significant or worrisome levels of BAC into the storm water system.

Example 3 - Sorbent Composition for Capturing a Target Chemical in Roof Run-off

[00167] A variety of suitable sorbent materials were investigated for their ability to efficiently sorb and hold QACs , especially aqueous solutions of BAC as used in commercial roof cleaning. [00168]A series of clean 25mm glass tubes, each 1200mm long were pretreated by heating to 350°C for 1 hour and then when cool filled with LAS (sodium dodecylbenzene sulphonic acid) dissolved in chloroform (0.4g IL) to blind off as many active sites within the glass as possible so that the absorbency of the material investigated was reflected as accurately as possible. One end of the tube was sealed with a Teflon frit 50μηι pore size, and the column filled with increasing depths of the absorbent material under investigation.

[00169]The sorbent composition was tamped during filling, with a PTFE rod and a 50g weight dropped

100mm (to compact the sorbent composition). Once filled to the correct height the column was stood upright and 1000ml of a fresh Synthequat LF solution in HPLC grade water was added, the liquid was collected in a PTFE bottle after passing through the absorbent, the post absorbent liquor was analysed for residual levels of QACs by the previously described HPLC-ESI- ToF/LIT method.

[00170]A variety of potential sorbents were investigated; pinus radiate chips, sawdust, attapulgite,

diatomaceous earth, activated charcoal, bentonite and smectite. These are readily available and considered as good industrial absorbents.

RESULTS

[00171] All of the materials selected showed some degree of sorptivity to varying degrees; the least

effective was pinus radiate chips and the most effective was diatomaceous earth.

[00172]The bentonite and smectite were very effective but swiftly formed plugs of puggy material which slowed the release of the liquid down to such an extent that they were discarded from further investigations. They also caused blocking of the frit and it was decided that on site use was not going to be practical.

[00173]The sawdust released an amount of copper chrome arsenate from tanalizing, despite it having been sourced from a sawmill that claimed not to process tanalized material. The sourcing of a reliable, clean and economic supply of sawdust may preclude its use.

Material length 0cm 10cm 20cm 30cm 40cm 50cm

Pinus 650 641 637 631 591 520

Sawdust 650 612 571 513 472 381

Attapulgite 650 489 391 201 56 0.02

DiatomaceousEarth 649 312 96 3 0.01 0.001

ActivatedCharcoal 652 376 119 38 0.5 0.1

Bentonite 651 338 111 NM NM NM Smectite 643 376 163 NM NM NM

NM = not measurable due to pugging. Expressed in ppm total CAC.

[00174] From the above results it was decided to look further into a combination of attapulgite,

diatomaceous earth and activated charcoal. A selection of combinations either as pairs or the triplet was investigated and a composition of maximum efficiency was discovered, this is approximately the following;

Attapulgite 50— 80 wt%

Diatomaceous Earth 20— 30 wt%

Activated Charcoal 5— 15 wt%

[00175]A typical set of results for this combination (Combination A) is given below:

Combination A length 0cm 10cm 20cm 30cm 40cm 50cm

652 201 18 0.23 0.003 <0.0002

[00176]Advantageously, this combination is shown to be particularly useful for sorption of cationic

surfactants from a liquid, as exemplified herein.

[00177]This composition provides all of the properties needed, economical, clean, readily available, reliable and user friendly. At the end of the absorbency life it can easily be added to compost as a soil conditioner or be disposed of in landfill without expected issues.

Longevity/Repeated Use Capacity for the Sorbent Composition

[00178] It is useful to determine the life span and efficiency over time, of a sorbent composition according to this invention.

[00179] A set of geotextile container as described was manufactured and filled with fresh sorbent

composition, they were then used on a recorded set of roofs, the recorded data was date, size of roof, number of droppers from gutter to spouting (the greater the number the lower the work rate of each container) the amount of chemical used and the level and type of contamination being cleaned from the roof.

[00180] A series of tests were conducted, on both laboratory and in field sites.

Experimental:

[00181] A set of sorbent composition filled geotextile containers (in the form of geotextile socks) were labelled and monitored for the types, sizes and state of roofs, after a known number of roofs had been cleaned and the run off treated, the geotextile containers were then opened, small samples removed and kept to one side in sealed jars. The containers were then resewn or closed and continued in use. This process was continued until a set of 30 known roofs run offs had been absorbed, at this point the samples were sent to the laboratory for analysis of the remaining absorbency potential. The openable end of the socks was randomly placed either towards or away from the spouting dropper during use.

[00182]The samples of absorbent were compared to virgin sorptivity (of a fresh sorbent composition) by the following methods;

i/ Measurement of continued absorbency by treatment of known fresh cleaning solution,

ii/ Measurement of the amount of QAC absorbed by extraction and analysis of the used absorbent, iii/ Measurement of the amount of QAC absorbed by measurement of the remaining surface area available for gas adsorption.

Method i.

[00183]Samples of the wet sorbent composition were taken and dried carefully over sodium metal for 24 hours in an atmosphere of dry argon, this drying method was selected to avoid any loss of volatile material such as benzyl amine that may have formed since the collection on site. From the dried sample a lOg was selected , placed on a piece of the specified geotextile and immersed for 1 hour in a fresh solution of the QAC in HPLC grade water, the immersion was conducted in a lidded PTFE boat to avoid losses from absorption on glass. A standard of fresh sorbent blend was treated the same way and the difference between the sample and the standard was measured by the previously described sample extraction followed by HPLC-ESI-ToF/LiT analysis.

Method ii.

[00184]Samples of the wet sorbent composition were taken and dried carefully over sodium metal for 24 hours in an atmosphere of dry argon, this drying method was selected to avoid any loss of volatile material such as benzyl amine that may have formed since the collection on site.

[00185]The sorbed QAC was extracted using the previously described method and then the level absorbed and extracted was measured using the previously described HPLC-ESI-ToF/LiT analytical method. This level was compared to the amount absorbed by fresh absorbent fully saturated with QAC for 24 hours and then dried as above, extracted and analysed.

Method iii.

[00186]Samples of both fresh sorbent composition and partially used sorbents were carefully dried for 24 hours over sodium. The level of absorbent activity was measured using ammonia gas allowed to equilibriate for 12 hours with the sample, any excess was then displaced by dry nitrogen which is known to weakly adhere to clay surfaces (Carter 1985, Macht 2010). The sample being analyzed was placed in an EV6 oven and then heated from 20°C to 180°C over a period of 20 minutes and held at 180°C for one hour to thoroughly desorb the ammonia, a carrier gas of dry argon was used at a flow rate of O.lL/min. The venting gases were collected to a Tenax trap. The trap septum was then transferred to a rapid purge device to release the collected ammonia under a flow of dry argon, this was connected to a Varian 3400 GC with a Saturn 3 mass spectrometer. A 30m DB5 type column was used with an oven temperature maintained at 180°C. The data was analyzed using a clarity program working on area under the peak to measure concentration released from a known weight of sample.

Results

Method i.

Number of roofs cleaned Loss of Sorptivity

10 a 1%

b 2%

c 1%

20 a 2%

b 2%

c 1%

30 a 3%

b 4%

c 4%

Method ii.

Number of roofs cleaned Sorbed QAC as a % of the standard.

10 a 2%

b 2%

c 1.5%

20 a 3%

b 4%

c 3%

30 a 5%

b 6%

5%

Method iii.

Number of roofs cleaned Level of remaining surface active sites.

10 a 99% b 98%

c 99%

20 a 97%

b 97%

c 98%

30 a 96%

b 95%

c 95%

[00187]These results all indicate that after 30 typical on site uses that the absorbent contained in the

geotextile containers are operating at approximately 95% of their original efficacy. This is regarded as a very safe margin of safety, as a discharge level of less than 1 part per billion might be expected from a 400mm long geotextile container used 30 times previously on typical roofs. This discharge figure is substantially below any current level of concern anywhere in the world and should be regarded as acceptable mitigation by legislators and regional councils.

Example 4 - EP Sock Runoff Test Summary

[00188]This example describes an assessment of water contamination from a variety of roofs typically used in New Zealand.

Method

[00189] Over a six month period from October to March a wide variety of roofs were studied for water contaminants sourced from the construction materials. These roof materials are typical of those found in New Zealand, and were a variety of ages - from newly installed, to those that had reached the end of their useful life. A known area of roof was washed with a controlled amount of water (the baseline composition of which was known), the water was collected both as passing directly into the stormwater system and also having passed through a sorbent system as described herein (hereafter the EPSock or EPSock filter). This enabled a comparative measure of the efficacy of the EPSock filters in the conditions expected to be encountered in the field. Each roof was

photographed, the weather recorded, the age of the EPSock being used and a consistent time lapse allowed before sampling the water.

[00190]The collected water was recovered in standard glass containers and kept refrigerated until analyzed.

The water samples were tested for the major contaminants of concern via ICP-MS for metal ions and GC-MS/MS + FID for polyaromatic hydrocarbons as per standard EPA guideline methodologies. Roof Types

[00191]The following numbers and types or construction materials were examined, with the split being approximately l/3rd Industrial facilities and 2/3rds being domestic dwellings.

Major Construction Material Number Comments

Unpainted galvanised Consistently high levels of zinc

Painted galvanized and coloursteel Produce Iron and Zinc, colour and age dependent

Butynol Plasticizers and Organic compounds

Wooden shingles High levels of Arsenic, Chromium, Copper and Organic Matter New Ashphalt Shingles 1 High levels of organic compounds Copper 1 Moderate levels of Soluble copper compounds

Pressed Metal Tiles 1 New Moderate levels of Zinc

3 Old High levels of Zinc and Iron Asbestos 1 High levels of entrapped organic matter and PAH's

Results

Analytical Summary

[00192]The most consistent source of Zinc and Iron are old unpainted galvanized iron long run roofs that are coming to the end of their lives.

[00193] New coloursteel roofs also produce small amounts of iron and zinc, and there was a correlation between colour and levels which suggests the paint system plays a role as oxide based pigment types were consistently higher than colours such as titania which have very little ferrous based pigmentation within them.

[00194] ubber based materials showed the release of internal plasticizers and oxidation products. Old asbestos roofs released large amounts of entrapped organic matter.

Contaminant levels - IRON

[00195]The highest level of iron found was 41ppm, the average level was typically 9.0 ppm without the EPSock, the average level with the EPSock was 0.018ppm and the highest level was off a very old roof that was being replaced at O.lllppm. [00196]The EPSock in these trials reduced the iron levels in stormwater run off to l/500th of its initial level. ZINC

[00197]The highest level found was 64ppm, the average level was typically 10.7 ppm without the EPSock, although the spread of results was very broad depending upon the age and condition of the roof. The average level with the EPSock was 0.014ppm and the highest level was again off an old roof that was being replaced at 0.089ppm.

[00198]The EPSock in these trials reduced the zinc levels in stormwater run off to l/750^th of its initial value.

COPPER

[00199]The highest level found was 3.6 ppm without the EP Sock. This was reduced in this case with the

EPSock to 0.067ppm which is a reduction of l/50th of its initial value. Although this was off a single result, it is illustrative of robust decontamination of copper from water run-off.

LEAD

[00200] Lead was typically associated with large industrial roofs. This may be a reflection of remaining lead headed nails as fixings or may be a legacy of environmental contamination stemming from the tetra ethyl lead additives historically added to petrol.

[00201]The highest level detected was 1.67ppm without the EPSock, and this was reduced to 0.021 ppm with the EPSock.

[00202]The EPSock in these trials reduced the lead levels in stormwater runoff to l/80^th of its initial value. ALUMINIUM, NICKEL

[00203]These elements were detected occasionally and the EPSock reduced their levels by l/100^th and l/200^th respectively.

Polyaromatic hydrocarbons

[00204]These compounds are of concern as they are of a potentially carcinogenic nature. They are generally introduced into the environment as by-products of internal combustion engines and domestic fires. The highest levels were found on commercial roofs used to house public transport. Levels of 3.6ppm without the EPSock was reduced to 0.003ppm with EPSock, being a reduction to l/1200^th of the original level. Notably, it was reassuring that domestic properties generally did not show PAH presence in the majority of cases.

Other Organic Compounds.

[00205]Several organic compounds were also detected, and these were confined to specific material types - such as plasticizers from rubberized sheets. [00206] In all cases, treatment with the EPSock reduced their levels by between l/100^th and l/300^th of the initial value.

Example 5 - Mitigation of roofing runoff contamination

[00207]This example describes an assessment of the presence of quaternary ammonium compounds

(QUATs or QACs) in runoff from a variety of roofs, and their removal using sorbent systems as described herein.

[00208]QACs are a common component of industrial cleaning compounds used for moss and mould control on roofs, gutters, drives and car parks. It is therefore to be expected that they would be found at some level in the run-off from these activities where these chemicals are used.

METHODS

[00209]Samples were taken over a two year long period of roof cleaning of a variety of roofing substrates, roof types, locations and contaminants. These varied from large scale coastal industrial facilities, through to urban domestic long run iron roofs of various ages.

[00210]Additional work was also conducted on a laboratory scale on old and new roofing materials, where the cleaning solution was run down a pitched 2m length of material and the run off collected and analyzed both initially and after a period of time, to mimic rainfall within a period of time that might be expected to assess QAC residual activity to determine if levels were still high enough to be of concern.

[00211]The wash off was done by applying the equivalent of 2mm of rainfall and collecting the last 50ml drain off from the area as it entered the gutter system.

[00212] During typical roof cleaning operations, the QACs are usually delivered on site as a concentrate and then diluted at a rate of 5L per 400L of water to give a slightly higher than 1% active ingredient solution for use on site. A typical application rate is lL/m², and thus a typical domestic dwelling of 250 m² actual roof area (allowing for eaves and corrugations) would utilize approximately 250 L of product. Published literature indicates an almost immediate decrease in activity of 90% during the cleaning process, and thus it is reasonable to project that each house could contribute

approximately 156g of excess QAC during a cleaning operation. Assuming that this is contained within the original 250L of water the concentration would be 0.63g/L as a maximum. This does not allow for any absorbance from detritus and debris contained within the gutters and spouting - QACs are well known to be attracted strongly via absorption to minerals such as clays, where they rapidly biodegrade. [00213]Standard solutions of both the QAC's used and their metabolites were made by dissolution using HPLC grade water, in a range from 500 parts per million (ppm) down to 5 parts per billion (ppb). These were used to calibrate an Agilent 1200 HPLC allied with an ESI Tandem ToF/LIT mass spectrometer for the analyses. The samples were filtered through a PTFE 5μηη frit immediately before injection as triplicate ΙΟμί aliquots, interspersed with matrix blanks and internal standards of 100 ppm and 100 ppb.

RESULTS

Roof Type Contamination Initial Level Washdown level

Level/type ppm(mg/L) 24 hrs ppm(mg/L)

Clean polycarbonate None 650 15

Clean scoria long run None 645 159

Clean karaka long run None 631 127

Clean painted scoria

long run None 481 49

Clean painted karaka

long run None 451 48

Clean new galva None 389 29

Clean new galvalume None 451 56

Newly installed long

run (hot day) None 710 160

Concrete tile Lichen 32 0.16

Long run Lichen 41 0.25

Long run Moss/Lichen 31 0.26

Long run Moss 18 0.11

Long run Lichen 26 0.18

Monier clay Lichen 34

Decramastic Lichen 14

Long run Lichen 36

Long run Lichen 35

Long run Lichen 34

Concrete Lichen 44 0.14

Concrete Lichen 37 Long run Lichen 29

Long run Moss/Lichen 22

Long run Lichen 27

Long run Lichen 29

Long run Lichen 28

Long run Lichen 31

Long run Lichen 45

Long run Lichen 41

Concrete Moss/Lichen 37

Average 32 0.185

Highest 44 0.260

[00214]The results above show a substantial reduction in QACs can be achieved using sorbent systems as described herein across a variety of roofing substrates and conditions.

Effect of Using EPSock with prewetted Mineral Absorbent.

[00215] A series of field trials were also undertaken with collection of the run off just before the EPSock and also at the base of the downspout with the run off having been passed through an optimal length of the EPSock filled with pre-wetted mineral. The mineral was pre-wetted to mimic the actual conditions encountered during use where it is very unlikely that the ESock would dry out due to immersion with dew and rain, even in a typical dry summer. HPLC grade water was passed through the EPSock which was then allowed to drain for 1 hour before use in a test.

Roof Type Contaminant Pre EPSock Post EPSock

Concrete Monier Clean 237 0.042

Decramastic Clean 241 0.031

Butynol New 244 0.022

Aged Butynol Clean 101 0.009

Polycarbonate Clean 237 0.038

Concrete Lichen 29 0.002

Long run Lichen 21 0.001

Painted Long run Lichen 19 0.001

Long run Moss/Lichen 17 0.001

Long run Moss/Lichen 27 0.001 Painted Concrete Lichen 26 0.001

Butynol Lichen 14 0.001

Life Span Efficacy OfEPSock

[00216] esults of run-off measurements with EPSocks used multiple times in the field have indicated a loss of performance of approximately 5% after 30 domestic roof cleaning operations - this was measured via % sorptivity, % QAC transmission of standard solutions and number of remaining active sites in the mineral blend.

[00217]These results establish the sorbent systems as described herein retain efficacy over long durations, indicating they can be installed permanently in certain circumstances and continue to mitigate the negative effects of chemical contamination over extended periods.

Storm water mitigation

[00218] Field testing and laboratory work has shown that the EPSock system dramatically reduces the level of organic polyaromatic hydrocarbon pollutants and metal ions present in stormwater runoff, and thereby prevents these chemical contaminants from entering the stormwater system. Typical reductions for metals were from 100s parts per million down to single digit parts per billion, and extended life uses do not release these contaminants as they are strongly bound within the crystal lattice of the EPSock absorbent materials.

[00219]Trials of capture of the chemicals used for pavement cleaning and maintenance have been

performed using large versions of the EPSock sorbent system which completely seal the storm drains set into the kerbs and gutters. These are placed before the cleaning process and capture the excess chemicals, grime, dirt and dead organic material produced and released by the cleaning process.

Example 6 - Stormwater Contaminants Capture

[00220]This example describes an assessment of sorbent systems as herein described to mitigate the reduction in stormwater quality stemming from the leaching of sediments and metals from roofs, car parks and roads. In particular, the efficacy of the sorbent systems to remove the principal contaminants copper, lead, and zinc - both as soluble salts and also particulates.

[00221] Notably, some of the levels of these chemicals exceed local stormwater guidelines for discharge. At the testing sites most stormwater reticulation was untreated, whereby untreated stormwater runoff is believed to impact the quality of biota, fauna and aquatic life in the riparian discharge routes - in this case, the River Avon in Christchurch.

[00222] ln addition to assessing copper, lead, and zinc, it was decided to include aluminium and iron as well as anions such as nitrate, sulphate and chlorides to enable a better understanding of the sources of these metal ions.

[00223]Accordingly, the aims of this experiment can be summarized as

a) does the EPSock capture the anions, and cations of concern?

b) once the ions are captured are they retained?

c) does the EPSock retain sediments? If so within what particle size distributions?

d) what is the useful performance life of the EPSock as a capture device?

Methods

[00224]Standard solutions of each individual ion were made in the concentration ranges shown below. It has been reported that a proportion of each metal is present as particulates. However, for this work it was decided to use soluble ions only as this could be considered a worst case scenario, especially as no particle size data was given for the metal particles - or even if they were alloyed with other metals.

Copper 3C^g/L

Zinc 25(^g/L

Lead l(^g/L

[00225]Solutions of iron and aluminium were also used, as these are also known to be associated with building material construction i.e., Zincalume coated roofing material, aluminium flashings on windows and exposed iron in gutters and downpipes.

Iron 10(^g/L

Aluminium 10C^g/L

[00226]The solutions were made using the relevant acetate in HPLC grade pure water and the numbers above refer to the amount of the metal present.

[00227]Additionally, speciation of anions was investigated as anti-corrosive pigments such as zinc

phosphate are known to be added to most roof paints at levels of up to 15% by weight of the dry paint film. It was considered important to try and confirm the source of zinc as many existing mitigation recommendations include suggestions to paint roofs as a mitigation measure. Other anions investigated were chloride, sulphate and nitrate as these can affect the solubilization of metal salts in acidic rainfall, and also acidity generated by organic material sitting in gutter systems accelerates the corrosion of these metals, especially zinc which has an amphoteric oxide film.

[00228]Sediments have also been identified as an area of concern, as levels up to 140mg/L (140,00C^g/L) have been reported in stormwater runoff. To test the efficiency of the EPSock in capturing sediments, slurries of calcium carbonate of known particle size distribution were made. These were classified using a coulter particle size analyser, both before and after passage through the EPSock filter system.

Equipment + Methods

[00229]A series of 65mm internal diameter PVC pipes were cut to 800mm lengths (a typical EPSock gutter dimension). These were sealed at the base with a piece of the specified EPSock geofabric held in place with an external pipe clamp, the pipe was then filled loosely with the EPSock sorbent composition to a depth of 750mm.

[00230] Each pipe was then wetted with 1500ml of HPLC grade water and the drained water was collected, the final lOOmL was collected for use as a matrix blank. Each pipe was then left to drain for 12 hours at 20 °C.

[00231] Each individual ion species was then passed through the wetted composition in lOOOmL quantities and the eluent collected for analysis. A total of 5000mL of each ionic solution was passed through the composition. A further 5000mL of HPLC grade water was also passed through each pipe, to investigate the retention of that ion within the EPSock sorbent composition. The eluent was collected in lOOOmL aliquots for analysis.

[00232]The eluent series was analysed using a DIONEX 5000 ion chromatograph and/or ICP-MS, using triplicate 20pL samples from each lOOOmL of eluent. The matrix blank was from the final lOOmL of the wetting eluent, and none of these samples showed leaching of any of the relevant ions to this study.

[00233] A master solution containing all of the cations, anions and sediments was also tested to investigate capture competition between these contaminants. Again, this was tested for both capture and retention after passage through an EPSock.

RESULTS

SEDIMENTS.

Particle Size % Retained % Retained after flushing

50μηη-80μηΊ 100 100

10μηΊ-15μηι 99 99 2μηΊ-5μιη 92 90

Combined equal volume 98 96

fractions Passing fraction was all <3μηι Passing fraction was al

<4μιη

CATIONS

Individual Species.

Cation Species Initial Cone Run off Cone after Run Off Cone after

EPSock flushing EPSock

Copper 30μ₈/ί 0 0 Zinc 250μ_δ/ί 2μg/L 0 Lead 10μ₈/ί 0 0

lron ³⁺ lOC L 0 0 Aluminium 100μ_δ/ί 0 0 Limit of detection is O^g/L

Mixed Species.

Cation Species Initial Cone Run Off Cone after Run Off Cone after

EPSock flushing EPSock

Copper 30μ₈/ί 0 0 Zinc 250μ_δ/ί 2 g/L 0 Lead 10μg/L 0 0 Iron ²⁺ 100μ_β/ί 0 lron ³⁺ 100μ_δ/ί 0 0 Aluminium 100μ₈/ί 0 0 Limit of detection is O^g/L

ANIONS

Individual Species

Species Initial Cone μg/L Cone after EPSock Cone after flushing

EPSock

Nitrate 100 0 0

Sulphate 100 0 0

Chloride 100 0 0 Limit of detection = 0^g/L Mixed Anions

Species Initial Cone pg/L Cone after EPSock after flush

EPSock

Nitrate 100 0 0

Sulphate 100 0 0

Chloride 100 0 0

Limit of detection = 0.5pg/L Polyaromatic Hydrocarbons.

[00234]These compounds are by products of petroleum combustion and are highly carcinogenic at relatively low levels. They are an EPA pollutant of high priority. The efficacy of sorbent systems as herein described was assessed against these compounds to determine whether the combination of high surface area combined with the unique intra-molecular activated carbon contained within the minerals could act as a capture and retainment composition.

[00235]A solution of naphthalene, fluorene, anthracene and chrysene was made at 10 ppm of each

compound in methylene chloride and then phase exchanged into a pure HPLC water. These were then passed through the EPSock sorbent system and the eluate analysed by HPLC - UV + HPLC MS/MS for any PAHs remaining in the stormwater as per EPA 6440B. The selected compounds had LoD's ranging between 1.8 and 0.15 pg/L.

[00236]These trials were repeated for the PAH blend on its own, the PAH blend in association with

sediments, the PAH blend with copper ions, the PAH blend with zinc ions and the PAH blend with iron ions

RESULTS

[00237] No levels above the individual LoD's were detected in the eluate (runoff water) after passage

through the EPSock sorbent system, irrespective of whether the PAHs were introduced to the sorbent system as a blend, or in association with the other contaminants above.

Example 7 - Useful Performance Life of an EPSock sorbent system in use

[00238]This example presents an assessment of the useful effective lifespan of EPSock sorbent systems as herein described when implemented in conditions similar to those present in various cities across New Zealand. [00239]Analysis of NIWA rainfall data indicates that Christchurch has an average annual rainfall of approximately 600mm, whilst Hamilton, Auckland and Wellington are 1100, 1200 and 1200 respectively.

[00240]A survey of local dwellings and industrial buildings gave an average roof area per dropper of

approximately 50 square metres. This equates to 30,000L of stormwater per dropper in

Christchurch and twice that in Hamilton, Auckland and Wellington.

METHOD

[00241]A master concentrate of the annual loading, per dropper, of anions and cations was produced along with sediment and PAH, to the levels described in Example 6 above, but contained in a 10L lot. This was analysed and checked for concentration of each component, then split into 12 equal aliquots.

[00242]A fresh EPSock test pipe was manufactured as described in Example 6 and this was again primed with 1500ml of HPLC grade water. Each test aliquot was then sequentially passed through the test pipe containing the sorbent composition, and the run off collected for testing. The liquid was added to the top of the test pipe over a 3 hour period and then allowed to drain for a further 9 hours, in an effort to mimic the cyclic wetting and drying that occurs naturally in a residential setting.

[00243]These collected aliquots were then analysed sequentially for all of the anions and cations of interest, plus sediment loading and PAH level.

RESULTS

[00244]The collected aliquots after passage through the EPSock ranged in collected size between 960 and 1020 ml. The numbers presented below are the % of each analyte remaining in the collected run- through aliquot. A figure of 0 represents a capture of sufficiently high efficacy such that the remaining analyte was below the limit of detection (LoD).

Species 1 2 3 4 5 6 7 8 9 10 11 12

Zinc 0 0 0 0 0 0.1 0.1 0.1 0.2 0.2 0.2 0.2

Copper 0 0 0 0 0 0 0 0 0 0 0 0

Aluminium 0 0 0 0 0 0 0 0 0 0 0 0

Iron ²⁺ 0 0 0 0 0 0 0 0 0 0 0 0

Iron ³⁺ 0 0 0 0 0 0 0 0 0 0 0 0

PAH 0 0 0 0 0 0 0 0 0 0 0 0

Sediment 0 0 0 0 0 0 0 0 0 0 0.1 0.1

Sulphate 0 0 0 0 0 0 0 0 0 0 0 0

Nitrate 0 0 0 0 0 0 0 0 0 0 1 2 [00245]The sediments that passed through the EPSock sorbent system were all below 5μιη and very mobile. CONCLUSION

[00246]The above results indicate that the EPSock sorbent system is a very effective capture media for all of the stormwater contaminants produced from roofs that are currently of concern.

[00247]The expected high efficacy life times, during which the sorbent system can be projected to work effectively and with a high degree of performance margin, for the various locations and annual average rainfalls is shown below.

LOCATION Roof Construction material Life Span of EPSock Efficiency

Auckland/Wellington/Hamilton Copper 1 year

Aluminium 1 year

Unpainted Zinc 1 year

Coloursteel 2 years

Christchurch/Hawkes Bay Copper 2 years

Aluminium 2 years

Unpainted Zinc 1 year

Coloursteel 2 years

Example 8 - Large scale roofing runoff mitigation

[00248]This example presents an assessment of the efficacy of an EPSock sorbent systems as herein

described when implemented on industrial roofs in Hamilton, New Zealand.

METHOD

[00249] Medium sized EPSock sorbent systems as herein described, comprising 3kg of sorbent composition in a geotextile container configured to fit within a header box, were installed in header boxes draining a part of two large, metal clad roofs typical of many industrial buildings. For comparison, untreated runoff was collected from the same roofs from downpipes that did not have an EPSock system installed. For each collection, temperature, rainfall level, date and time was recorded.

[00250] Roof B was an unpainted zinc coated trimdeck profile roof of a low (approximately 8°) pitch. The feed area to the header box was approximately 150 m², via 150 mm diameter half round clean gutters in good condition. The roof was approximately 24 years old.

[00251]The EPSock sorbent system was installed approximately 10 months prior to the samples assessed below. During that time, the approximate total rainfall for Hamilton was 1260 mm. Samples were taken during mid-afternoon. Metal ions were measured with ICP-MS, PAHs were measured using GC-MS/MS, and QACs were measured via HPLC - Tof/LitMS. RESULTS

[00252]The samples collected from the EPSock sorbent system treated runoff from each roof (A, and B) approximately 10 months after installation were assessed as described above, and the results are shown below. A reading of 0 is below the limit of detection.

Table 2. Contaminant levels

[00253]These results show very effective removal of the recited contaminants after long-term installation of a larger format sorbent system in header boxes of two industrial metal roofs.

SUMMARY

[00254]The above examples demonstrate that the sorbent compositions, geotextile containers, and sorbent systems as described herein are able to immediately and effectively capture cationic surfactants such as QAC (specifically BAC) from a contaminated roof run-off. The sorbent compositions, geotextile containers and sorbent systems described herein are economic, practical, efficient, clean and reliable to use. The superior performance of the compositions, containers and systems to capture contaminants such as cationic surfactant contaminants is believed, without wishing to be bound by any theory, to in one way be attributable to the anionic surfaces present in at least one minerals present in the sorbent compositions, which enables the mineral to rapidly and strongly absorb onto the positively charged cationic surfactant.

[00255]Similarly, the at least one mineral of this invention is anticipated to also work equally effectively to sorb other chemicals, e.g. other positively charged chemical species in the solution, including the metal ions (such as Pb²⁺ or Cd²⁺ and the like) or other positively charged organic/inorganic species. In an embodiment that also includes at least one other mineral and/or activated charcoal in the sorbent composition, the composition is effective for sorbing cationic, anionic and/or neutral chemical pollutant species in a liquid.

[00256]The entire disclosures of all applications, patents and publications cited above and below, if any, are herein incorporated by reference.

[00257] Reference to any prior art in this specification is not, and should not be taken as, an

acknowledgement or any form of suggestion that that prior art forms part of the common general knowledge in the field of endeavour in any country in the world.

[00258]The invention may also be said broadly to consist in the parts, elements and features referred to or indicated in the specification of the application, individually or collectively, in any or all combinations of two or more of said parts, elements or features.

[00259] Where in the foregoing description reference has been made to integers or components having known equivalents thereof, those integers are herein incorporated as if individually set forth.

[00260] It should be noted that various changes and modifications to the presently preferred embodiments described herein will be apparent to those skilled in the art. Such changes and modifications may be made without departing from the spirit and scope of the invention and without diminishing its attendant advantages. It is therefore intended that such changes and modifications be included within the present invention.

Claims

1. A sorbent composition for sorbing one or more chemicals from a liquid, the composition comprising activated charcoal; and

at least one porous non-swelling mineral having an anionic surface comprising hydroxyl groups and a high specific surface area of at least 100 m²/g.

2. The composition of claim 1 wherein the at least one mineral has a low bulk density.

3. The composition of claim 1 or claim 2 wherein the at least one mineral is selected from the group consisting of diamaceous earth, attapulgite, sepiolite, and zeolite.

4. The composition of any one of claims 1 to 3 wherein the at least one mineral has a high specific surface area of at least 100 m²/g.

5. The composition of any one of claims 1 to 4 wherein the sorbent composition has a high specific surface area of at least 120 m²/g, of at least 150 m²/g, at least 175 m²/g, at least 200 m²/g, at least 220 m²/g, at least 240 m²/g, at least 260 m²/g, at least 280 m²/g, at least 300 m²/g, at least 320 m²/g, at least 340 m²/g, at least 360 m²/g, at least 380 m²/g, or at least 400 m²/g.

6. The composition of any one of claims 1 to 5 wherein the sorbent composition has a high specific surface area in the range of

a) 150 - 600 m²/g,

b) 150 - 500 m²/g, or

c) 175 - 400 m²/g.

7. The composition of any one of claims 1 to 6 wherein the sorbent composition comprises activated charcoal and one or more minerals selected from the group consisting of of diamaceous earth, attapulgite, sepiolite and zeolite.

8. The composition of any one of claims 1 to 7 wherein the activated charcoal is contiguously

dispersed in the one or more minerals of the sorbent composition.

9. The composition of claim 8 wherein the activated charcoal is contiguously dispersed in

diatomaceous earth and/or attapulgite.

10. The composition of any one of claims 1 to 9 wherein the activated charcoal comprises fine particles that are contiguously and/or substantially evenly distributed within particles of the one or more minerals.

11. The composition of any one of claims 1 to 10 wherein the sorbent composition comprises a

combination of two or more minerals.

12. The composition of any one of claims 1 to 11 wherein the sorbent composition comprises:

a) 50 - 80 wt% Attapulgite;

b) 20 - 30 wt% Diatomaceous Earth; and

c) 5 - 15 wt% Activated Charcoal.

13. The composition of any one of claims 1 to 12 wherein the attapulgite in the sorbent composition has high specific surface area in the range of 150 - 350 m²/g or 175 - 330 m²/g.

14. The composition of any one of claims 1 to 13 wherein the attapulgite in the sorbent composition has one or more of the following properties:

a) specific surface area of from about 200 to 300 m²/g;

b) oil retention value of from about 20 -30% w/w;

c) cationic exchange capacity of from about 0.2 to about 0.4 mq/gm;

d) any combination of two or more of a) to c) above; or

e) each of a) to c) above.

15. The composition of any one of claims 1 to 14 wherein the activated charcoal in the sorbent

composition has high specific surface area in the range of 200 - 400 m²/g, or 250 - 350 m²/g.

16. The composition of any one of claims 1 to 15 wherein the activated charcoal in the sorbent

composition has one or more of the following properties:

a) specific surface area of from about 280 to about 320 m²/g; and/or

b) a mean particle size of less than 10 μηη.

17. The composition of any one of claims 1 to 16 wherein the at least one mineral, and/or the activated charcoal, and/or the composition is present as a powder, particles, granules, pellets or is in extruded form.

18. The composition of any one of claims 1 to 17 wherein the sorbent composition further comprises a pack filler material and/or a material with water retention properties.

19. A sorbent system for sorption of one or more chemicals from a liquid, the system comprising

a container having an elongated body defining an inner cavity for holding the sorbent composition, the container formed from a porous material capable of retaining the sorbent composition therein; wherein, in use, a body portion of the container holding the sorbent composition will have a volume that will result in at least 30% of the one or more chemicals in the liquid being sorbed.

20. The system of claim 19 wherein the container enables a liquid carrying one or more chemicals to pass through the porous material on one side or end of the container, to reach and be treated by a sorbent composition held within the container, then the treated liquid may exit the porous material on an opposing side or end of the container.

21. The system of claim 19 or claim 20 wherein the container is at least partially formed from a

geotextile fabric.

22. The system according to any one of claims 19 to 21 wherein, in use, a body portion of the container holding the sorbent composition will have a volume that will result in at least 30% of the one or more chemicals in the liquid run-off being sorbed.

23. The system according to any one of claims 19 to 22 wherein the elongated body portion of the

container having an in inner cavity for holding the sorbent composition has an openable end for receiving the sorbent composition, and a sealed end to secure the sorbent composition within the inner cavity.

24. The system according to any one of claims 19 to 23 wherein the porous material for forming the container has one or more of the following:

a) a porosity of from about 20 to about 90 μιη,

b) a tensile strength in the range of 6 - 15 N/m²;

c) a thickness in the range of 1 - 10 mm;

d) any combination of two or more of a) to c) above; or

e) each of a) to c) above.

25. The system of any one of claims 21 to 24, wherein the geotextile fabric forming at least a part of the container comprises a polypropylene, polyester, polyurethane or other similar synthetic polymeric material in woven, needle punched, needle felt, or heat bonded form.

26. The system of any one of claims 21 to 25, wherein the geotextile fabric forming at least a part of the container has one or more of the following:

a) a tensile strength of at least about 6 kN/m²;

b) a burst strength of at least about 3 kN/m²;

c) a thickness of from about 1.1 to about 8 mm;

d) any combination of two or more of a) to c) above; or

e) each of a) to c) above.

27. The system of any one of claims 21 to 26, wherein the geotextile fabric forming at least a part of the container has one or more of the following:

f) a tensile strength of at least about 9 kN/m²;

g) a burst strength of at least about 6.4 kN/m²;

h) a thickness of from about 1.4 to about 1.6 mm;

i) an average pore size of at least about 50μιη;

j) transplanar transmissivity of at least about 6L per minute;

f) crossplanar transmissivity of at least about 3.4L per minute;

g) any combination of two or more of a) to f) above; or

h) each of a) to f) above.

28. The system of any one of claims 19 to 27 wherein the container is at least partially formed from a porous polyester needlefelt fabric.

29. The system of any one of claims 19 to 28 wherein the container has a substantially elongated sock or tube design, having a body length of from about 20 cm to about 300 cm and a width of from about 3 cm to about 50 cm.

30. The system of any one of claims 19 to 29 wherein the weight of sorbent composition for filling the container is from about 100 g to about 5000 g.

31. The system of any one of claims 19 to 30 wherein the container contains sufficient sorbent

composition to result in at least 30% of the one or more contaminating chemicals in a liquid being sorbed.

32. The system of any one of claims 19 to 31 wherein the container is formed from a geotextile fabric, and the body portion of the container holding the sorbent composition has

a) a length in the range of 20 - 300 cm, and a cross-sectional diameter in the range of 3 - 50 cm; b) a length in the range of 50 - 200 cm, and a cross-sectional diameter in the range of 5 - 40 cm; c) a length in the range of 80 - 150 cm, and a cross-sectional diameter in the range of 7 - 30 cm; d) a length in the range of 90 - 110 cm, and a cross-sectional diameter in the range of 8 - 12 cm; or

e) a length in the range of 30 - 100 cm, and a cross-section diameter in the range of 5 - 15 cm.

33. The system of any one of claims 19 to 31 wherein the system is for a roof drainage system and the the body portion of the container holding the sorbent composition has a length in the range of 30 - 200 cm, and a cross-sectional diameter in the range of 5 - 25 cm.

34. The system of claim 33 wherein the body portion of the container holding the sorbent composition has

a) a length from about 50 cm to about 150 cm,

b) a length from about 70 cm to about 120 cm,

c) a length from about 80 cm to about 105 cm,

d) a length from about 90 cm to about 100 cm,

e) a cross-sectional diameter from about 6 cm to about 20 cm,

f) a cross-sectional diameter from about 7 cm to about 15 cm,

g) a cross-sectional diameter from about 8 cm to about 12 cm,

h) a cross-sectional diameter from about 9 cm to about 10 cm, or

i) any combination of one of a) to d) and one of e) to h).

35. The system of any one of claims 19 to 31 wherein the volume of sorbent composition present is a) from about 2000 cm³ to about 7000 cm³,

b) from about 2500 cm³ to about 6800 cm³,

c) from about 2500 cm³ to about 6200 cm³,

d) from about 2500 cm³ to about 6000 cm³,

e) from about 2500 cm³ to about 5800 cm³,

f) from about 3000 cm³ to about 6800 cm³, g) from about 3000 cm³ to about 6200 cm³,

h) from about 3000 cm³ to about 6000 cm³,

i) from about 3000 cm³ to about 5800 cm³,

j) from about 3500 cm³ to about 6800 cm³,

k) from about 3500 cm³ to about 6200 cm³,

1) from about 3500 cm³ to about 6000 cm³,

m) from about 3500 cm³ to about 5800 cm³,

n) from about 4500 cm³ to about 6800 cm³;

o) from about 4500 cm³ to about 6200 cm³;

p) from about 4500 cm³ to about 6000 cm³; or

q) from about 4500 cm³ to about 5800 cm³.

36. A method of removing one or more chemical contaminants from a liquid in a roof drainage system, the method comprising

placing a sorbent system according to any one of the preceding claims in a passage within the drainage system through which the liquid has to flow,

37. The method of claim 36 wherein the sorbent system is placed in a roof drainage system.

38. The method of claim 37 wherein the sorbent system is placed in one or more of a gutter (spout), a drop outlet (droppers), a downpipe or downspout (leader), or a header box (header).

39. A method of removing one or more chemical contaminants from a liquid in a storm or surface water drainage system, the method comprising

40. The method of any one of claims 36 to 39 wherein the sorbent system is placed so as to

substantially occupy the passage to minimise the flow of liquid around the sorbent system and maximise the flow of liquid through the sorbent system.

41. The method of any one of claims 36 to 40 wherein the sorbent system is shaped or configured to substantially conform to the shape and/or dimension of the receiving site.

42. A method of removing one or more chemical contaminants from a liquid in a drainage system, the method comprising

placing a sorbent system according to any one of the preceding claims near, at or just outside drainage point from or of the drainage system through or to which the liquid will flow, wherein at least a portion of the one or more chemical contaminants present in the liquid will sorbed by the sorbent system as the liquid passes through the sorbent system.

43. The method of claim 42 wherein the sorbent system is placed on or in the ground to filter a liquid run-off discharged from a downpipe or an exit of a roof drainage system, or to filter run-off from a surface.

44. The method of any one of claims 36 to 43 wherein a plurality of sorbent systems is applied

simultaneously.

45. The method of claim 44 wherein a plurality of sorbent systems is bundled or stacked together, optionally then placed inside one or more geotextile containers or receptacles.

46. The method of any one of claims 43 to 45, wherein the surface is a paved surface, a road, a

driveway, a carpark, a field, a pasture, a residential, civil, or commercial site, a residential, civil or commercial building site, a wastewater treatment plant, or the like.

47. The composition of any one of claims 1 to 18, the system of any one of claims 19 to 35, or the method of any one of claims 36 to 46, wherein one or more of the chemicals present in the liquid and/or to be sorbed is selected from the group consisting of

a) one or more quaternary ammonium compounds;

b) one or more metals or metal ions;

c) one or more phosphates;

d) one or more nitrates;

e) one or more nitrites;

f) one or more halides;

g) one or more organic compounds;

h) any combination of two or more of a) to g) above; or i) each of a) to g) above.

48. The composition, system or method of claim 47, wherein the one or more metals or metal ions is or comprises zinc, iron, aluminium, lead, nickel, or copper.

49. The composition, system or method of claim 47, wherein the one or more organic compounds is a polycyclic aromatic hydrocarbon, a polynuclear aromatic hydrocarbon, naphthalene, fluorene, anthracene, or chrysene.