WO2019152188A1

WO2019152188A1 - Method and apparatus for reducing contaminants in wastewater

Info

Publication number: WO2019152188A1
Application number: PCT/US2019/013734
Authority: WO
Inventors: Shunqing CHEN; Ajikumar CHRYSTALBAI
Original assignee: The Procter & Gamble Company
Priority date: 2018-01-30
Filing date: 2019-01-16
Publication date: 2019-08-08

Abstract

A method (200, 400) for reducing contaminants in wastewater from a manufacturing process. Water is fed into a processing tank (102) that has been used to process one or more materials having negatively charged particles that become contaminants in wastewater. The water becomes mixed with the contaminants forming wastewater which is discharged into a wastewater tank (13). A water treatment composition is added to the wastewater tank (13) containing the wastewater. The water treatment composition has a coagulant having one or more water-soluble multi-valent inorganic salts or mixtures thereof. The coagulant attracts and neutralizes the negatively charged particles in the wastewater to form insoluble matter. The insoluble matter is removed to obtain treated wastewater with reduced contaminants.

Description

METHOD AND APPARATUS FOR REDUCING CONTAMINANTS IN WASTEWATER

FIELD OF THE INVENTION

The present invention relates generally to the field of treatment for wastewater. More particularly, the present invention relates to a method and an apparatus for reducing the level of contaminants in wastewater from manufacturing processes, particularly those that include volatile liquids.

BACKGROUND OF THE INVENTION

Cleaning and washing of industrial equipment used in chemical manufacturing plants such as product containers and mixing tanks generate large volumes of wastewater. For example, industrial equipment used for manufacturing oil-based products such as perfume products can generate waste water comprising volatile liquids such as aromatic oils, microorganisms, and colloidal and/or suspended particles and solids, and microorganisms (hereinafter“contaminants”). The presence of volatile liquids and microorganisms may result in a high level of chemical oxygen demand (“COD”) in the wastewater. Wastewater with high levels of COD generally cannot be discharged into the environment through ordinary sewage systems because the wastewater can decrease oxygen supply in water bodies and negatively affect aquatic life in the water bodies. As such, COD rich wastewater is typically incinerated which is costly and increases overall operation costs. Alternatively, the wastewater may be subject to one or more pre-treatment processes to reduce the levels of COD and other chemicals in the wastewater. A conventional wastewater pre-treatment process typically involves a number of separate steps including flocculation, sedimentation, media filtration to remove colloidal and suspended solids, and disinfection.

However, such processes are complex, costly and require long processing times as many steps are involved in the processes. Therefore, there remains a need for a simple and cost- effective method for reducing contaminants in wastewater.

SUMMARY OF THE INVENTION

The present invention relates to a method for reducing the level of contaminants in wastewater from a manufacturing process, the method comprising the steps of;

(i) feeding water into a processing tank that has been used to process one or more materials having negatively charged particles that become contaminants in wastewater; (ii) washing the processing tank with the water, wherein the water becomes mixed with the contaminants forming wastewater;

(iii) discharging the wastewater into a wastewater tank;

(iv) adding water treatment composition to the wastewater tank, the water treatment composition comprising a coagulant selected from the group consisting of: one or more water-soluble multi- valent inorganic salts and mixtures thereof, wherein the coagulant attracts and neutralizes the negatively charged particles in the wastewater to form insoluble matter; and

(v) removing insoluble matter to obtain treated wastewater with a reduced level of contaminants.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of a system for reducing contaminants in wastewater according to the invention;

FIG. 2 is a process chart of a method for reducing contaminants in wastewater according to the invention;

FIG. 3 is a schematic diagram of a system for recovery of wastewater from a manufacturing process according to the invention; and

FIG. 4 is a process chart of a method of recovery of wastewater from a manufacturing process according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to a method of treating wastewater and a wastewater treatment apparatus for reducing a level of contaminants in wastewater, for example, from a manufacturing process, such as the manufacture of chemicals. Wastewater fro manufacturing processes often comprises contaminants including but not limited to volatile organic compounds, suspended particles and solids, and volatile liquids. Such volatile liquids may comprise any hydrophobic organic liquid such as for example, aromatic oils, liquid hydrocarbons such as crude oil and oil-based products. Aromatic oils may comprise terpenes, esters, aldehydes or any volatile liquid used for making perfumes.

Prior to describing the present invention in detail, the following terms are defined and terms not defined should be given their ordinary meaning as understood by a skilled person in the relevant art. “Inorganic metal salt” as used herein, includes all poly-variations thereof such as polyaluminum chloride and polyferric material, but does not include compounds comprising methyl or ethyl groups.

“Inorganic metal salts which are free from carbon atoms” as used herein, includes sources of inorganic metal salts winch comprise minor amounts of carbon impurity such as often found in naturally occurring inorganic metal salt sources.

“Amine group” as used herein, includes primary amine groups, secondary'· amine groups, tertiary amine groups, quaternary_' amine groups such as quaternary ammonium groups, but does not include amide groups.

“A low amount of substantially water-soluble organic content” as used herein, refers to having a total organic content (TOC) of purified water of less than 10 ppm, preferably less than 7 ppm, more preferably less than 4 ppm as determined by Water Solubility Test Method described hereinafter.

“Substantially water-insoluble” as used herein, refers to having at least 10% by dry total weight of undissolved material present as determined by the Water Insolubility Test Method described hereinafter.

“Highly porous aerogel” as used herein, refers to aerogels based on the chemical element carbon with open pores and a high porosity (up to ca. 99.5 %) which are flexible and have a sponge-like texture. The structure of the obtained aerogel depends on the carbon raw material used as starting material. In case cotton is used as the carbon raw' material, the obtained aerogel has an interconnected twisted carbon fiber (TCP) structure. The fibers in such a TCP aerogel show a diameter of 5 to 10 pm and a twisted morphology with a pitch length in the range of 10 to 20 p . These fibers are cross-linked. When paper is used as carbon raw material the resulting aerogel shows the same structure as the TCP aerogel, but the libers of the manufactured aerogel are belt-like and not twisted. Most of the belt-like fibers are 5 to 10 pm wide and are cross-linked with each other resulting in advantageous mechanical properties, such as stiffness. This type of aerogel is referred to herein as a carbon microbelt (CMB) aerogel and is obtained by using paper and/or wastepaper as carbon raw' material. The aerogels have, due to their structure and porosity, a large surface area which makes them particularly suitable for adsorbing a wide range of organic solvents and oils.

In the following description, the wastewater treatment apparatus described is an apparatus for reducing a level of contaminants in wastewater from the manufacture of perfumes for use in consumer products such as for example, haircare products, skincare products, personal cleansing products, household detergent products, air freshening products or the like. Accordingly, the method described is a method for reducing a level of contaminants in wastewater from the manufacture of perfumes for use in consumer products. However, it is contemplated that the apparatus and the method may be configured for use in a variety of applications to reduce contaminants in wastewater including, but not limited to, the manufacture of oil-based products not limited to consumer products containing perfumes and/or the manufacture of other products wherein the manufacturing process results in wastewater including contaminants.

FIG 1 is a schematic drawing of a wastewater treatment apparatus 10 according to the present invention deployed in a system 100 for recovery of treated wastewater. Referring to FIG. 1, the system 100 includes a water supply feedline 101 for supplying clean water for washing, a processing tank 102 in fluid connection with the water supply feedline 101 for cleaning the processing tank 102, and the wastewater treatment apparatus 10 is disposed downstream from the processing tank 102. The processing tank 102 may be any equipment used in a process for manufacturing perfumes including for not limited to packing containers for storage of chemicals, process containers for processing chemicals and mixing tanks for mixing one or more chemicals in intermediate steps of a manufacturing process. The processing tank 102 may he connected to the water supply feedline 101 for receiving water for washing the processing tank 102. A wastewater storage tank 103 may be positioned downstream the processing tank 102 to receive and store wastewater from washing the processing tank 102. The wastewater treatment apparatus 10 is located downstream the wastewater storage tank 103 and may comprises a wastewater tank 13 having a first inlet 14 in fluid communication with the processing tank 102 for receiving wastewater discharged during/after washing of the processing tank 102. A second inlet 15 is arranged about the wastewater tank 13 for receiving a water treatment composition for treating the wastewater comprising a mixture of water and contaminants having negatively charged particles. The wastewater tank 13 may comprise a mechanical agitator 17 for mixing the water treatment composition with the wastewater so that the wastewater becomes mixed with the water treatment composition. As described in more detail below, the water treatment composition comprises a coagulant that attracts and neutralizes the negatively charged particles in the wastewater to form insoluble matter. A first outlet 16 is disposed within the wastewater tank 13 to allow' for removal of insoluble matter from the w^rastewater so as to provide treated wastewater with a reduced level of contaminants. The wastewater tank 13 comprises a second outlet 18 for discharging the treated wastewater from the wastewater tank 13 for reuse in manufacturing/industrial facilities where the wastewater is produced or for post-treatment, an example of which is described later with reference to FIGS. 3 and 4.

In an exemplary embodiment in which the apparatus 10 is deployed within a manufacturing process of a manufacturing facility, the second outlet 18 may be in fluid communication with a different processing tank for washing with the treated waste water such as through a treated wastewater feedline for returning the treated wastewater to the processing tank 102 for a second washing process in the cleaning of the processing tank 102.

FIG. 2 is a process chart illustrating a method 200 according to the present invention for reducing the level of contaminants in wastewater from, for example, a manufacturing process. Referring to FIG. 2, the method 200 comprises step 201 of feeding water into a processing tank 102 followed by a step 202 of washing the processing tank 102. The step 202 of washing the processing tank 102 may include any conventional means, including but not limited to spraying or jetting the water into the processing tank 102. The wastewater may be left in the processing tank 102 to stand for a predetermined period of time to remove water-soluble chemical material deposited on inner walls of the processing tank 102. The wastewater is then discharged in step 203 from the processing tank 102 to the wastewater tank 13 and the water treatment composition is added to the wastewater in the wastewater tank 13 in step 204. The water treatment composition may be added in an amount of at least 400 ppm by weight of the wastewater, preferably from about 400 ppm to about 4000 ppm by weight of the wastewater it will be appreciated by a person skilled in the art of water treatment systems that an amount of the water treatment composition to be added to the wastewater may depend on the level of contaminants in the wastewater and/or the level of treatment desired and may be varied accordingly. For example, a smaller amount of the water treatment composition may be needed to treat wastewater with a lower level of contaminants compared to the amount of the water treatment composition needed to treat wastewater with a high level of contaminants.

In step 204, upon adding the water treatment composition to the wastewater, the coagulant in the water treatment composition generates a positively charged precipitate which attract negatively charged particles present in the wastewater and neutralize the particles. As the particles are neutralized, these particles do not carry a charge forming neutralized particles which stick together to form agglomerated particles. The agglomerated particles and the insoluble precipitate forms insoluble matter which is removed from the wastewater tank 13 in step 205 through a first outlet 16 of the wastewater tank 13, as shown in FIG. 1 to obtain treated wastewater with a reduced level of contaminants. The insoluble matter may be removed or separated from the remaining part of the treated wastewater by any technique, typically by filtration, but decanting, sedimentation and flotation may also be used. Suitable filters include cloth filters, non-woven and paper filters, and polishing filters, such as filters comprising activated carbon, glass fibre, zeolite, ion exchange media, or a combination thereof, which remove residual water-impurities, e.g. organic matter, heavy metal ions and residual disinfectant from the water. The filters may be impregnated with silver or other biostatic components so that bacteria cannot grow on said filter and the filter can be reused se veral times without contaminating the water being filtered. Sand filters can also be used, and more than one filter may be used in combination herein.

The insoluble matter also absorbs the volatile liquid present in the wastewater. Therefore, when the insoluble matter is removed from the treated wastewater, the volatile liquid is also removed simultaneously. Removal of the volatile liquid and the insoluble matter reduces particles present in the wastewater and a COD level of the wastewater, thereby the treated wastewater may be recovered for purposes such as for example, washing of mixing tanks used in manufacture of oil-containing products such as perfumes.

The wastewater treatment apparatus 10 may be co-located with the processing tank 102 used in a manufacturing process to enable treatment of the wastewater in a single step, thereby reducing a level of contaminants in the wastewater and eliminating the need for additional processing steps typically required for removing particles from the wastewater at the same time. However, it is also contemplated to have the wastewater treatment apparatus 10 be located at a different location from the processing tank 102 through configuration of feed line arrangements which are known to persons skilled in the art of industrial automation. Such separate processes may be preferred when the manufacturing location does not have space for the additional wastewater tank 13 and/or if a separate process for treating the wastewater is desirable for other reasons, such as, for example, when the treatment process is faster than or slower than the manufacturing process, where a separate group or company is handling the wastewater treatment and/or when it is preferred to treat the wastewater at a different time than when it is generated. A technical effect of the present invention is that the time required for wastewater treatment can be significantly reduced relative to conventional wastewater treatment processes. Wastewater Treatment Composition

The water treatment composition herein may be in any suitable form, including but not limited to a solid unit dose form such as a tablet or a dissolvable unit dose filled with powder liquid, gel or a combination of one or more material forms. The water treatment composition may also be in the form of a bulk powder, a liquid, foam, gel or any other suitable material. The water treatment composition herein may be provided in a package so that it is protected from environmental conditions such as moisture. The package may comprise a water impermeable material such as polypropylene or typical laminates. An example of one such laminate is a laminate supplied by Akerlund & Raus, comprising layers of coated paper (outer), LDPE, aluminium foil and an inner layer Surlyn (an ethylene/methacrylate co-polymer)— an FDA approved food packaging.

The water treatment composition preferably comprises a coagulant selected from the group consisting of: one or more water-soluble multi- valent inorganic salts and mixtures thereof. The one or more water-soluble multi-valent inorganic salts may be an inorganic metal salt selected from the group consisting of iron sulphate, iron chloride, manganese sulphate, manganese chloride, copper sulphate, copper chloride, aluminium sulphate, aluminium chloride, poly- variations thereof, and combinations thereof. The inorganic metal salt of the water treatment composition may be selected on the basis that it can act as a coagulant and can interact with charged water-soluble impurities in such a manner so as to neutralise the charge of said water-soluble impurity to form a water-insoluble impurity, usually to form a water-insoluble salt of said impurity, which precipitates out of solution. The inorganic salt of the water treatment composition may also lower the turbidity of the water by increasing the particle size of the water-insoluble impurities possibly causing sedimentation or facilitating the removal of these water-insoluble impurities by filtration or other water-insoluble matter removal techniques such as flotation or decanting. The inorganic salts may also co-precipitate heavy- metal ions out of water, and can also lower the total organic content present in the water by coagulating or adsorption of this organic content onto the water- insoluble impurities which have been formed in the water. The inorganic metal salt of the water treatment composition may be a multivalent, preferably a di- or tri- valent, inorganic metal salt such as, aluminium III sulphate, iron II (ferrous) sulphate or iron III (ferric) sulphate. The inorganic metal salt may be free of carbon atoms. Inorganic metal salts of the water treatment composition may comprise (by weight of said salt) less than 5%, less than 3%, less than 1%, less than 0.1%, less than 0.01% carbon atoms. Inorganic metal salts which are a source of acid, such as aluminium III sulphate or iron sulphate may also be used. The water treatment composition may also comprise a source of carbonate such as sodium carbonate. The carbonate source provides an optimized pH for coagulation. The acid source and the carbonate source may react together to form a gas. This process is known as effervescence and helps to disperse the water treatment composition herein, especially when the water treatment composition herein is in the form of a tablet.

The water treatment composition herein may comprise (by weight) from 1%, or from 5%, or from 10%, or from 15%, or from 20%, or from 25%, and to 50%, or to 40%, or to 30% inorganic salt selected from the group consisting of iron sulphate, iron chloride, manganese sulphate, manganese chloride, copper sulphate, copper chloride, aluminium sulphate, aluminium chloride, poly- variations thereof, and combinations thereof.

The water treatment composition herein may comprise a coagulant aid. Preferred coagulant aids are polymeric materials which comprise an amine group and which are cationic in nature. The coagulant aid may be selected on the basis that it can aid a coagulation and flocculation process and in particular can, in conjunction with the primary' coagulant, aid particle adherence and the aggregation of water-insoluble particles into larger water-insoluble aggregated complexes known as floes. The coagulant aid may also adsorb or coagulate oils, fats and other organic or inorganic matter, and may sequester heavy metal ions. The amine group can be the group linking the monomeric units of the backbone of the polymeric material, or may be present as a side group of the polymeric material, for example as an amine side group of a polysaccharide. The amine group may be present as a side group. The coagulant aid may^¬ be substantially water-insoluble.

The amine group of the coagulant aid may be at least partly protonated when the coagulant aid comes into contact with water, typically this protonation reaction occurs at a pH of below 9 0, and preferably at a pH of from 3 to 8. Thus, preferably the coagulant aid is cationic when in a solution of water at a pH of below 9. Alternatively, the am ine group of the coagulant aid may already be in a charged state, for example a substituted or protonated state. The amine group of the coagulant aid may be a cationic quaternary ammonium group.

The coagulant aid may comprise a polysaccharide comprising an amine group. The coagulant aid may comprise a cationic starch, for example, cationic starch obtained from potato starch, waxy maize starch, corn starch, wheat starch and rice starch. The coagulant aid may comprise a polysaccharide which comprises an amine group which is bound directly to the monomer saccharide backbone unit of said polysaccharide. Alternatively, the coagulant aid may comprise a polymer of glucosamine where all the monomer saccharide backbone units are connected in a linear conformation via beta-l-4-giycosidic bonds. The coagulant aid may comprise a modified chitin, such as chitosan, modified chitosan, or salts thereof. The coagulant aid may comprise chitosan or modified chitosan. The coagulant aid may be an impurity of chitin, and therefore, chitin may be a preferred source of coagulant aid for use herein. Chitosan suitable for use herein may be derived from the chitin of Crustacea such as crabs, lobsters and shrimps. Chitosan derived from the chitin of fungi can also be used herein. Hie chitosan for use herein is typically found in the shells of Crustacea and can be extracted by any technique known in the art, for example by using the extraction techniques described in U.S Pat. Nos. 3,533,940, 3,862,122, 3,922,260 and 4,195,175.

The coagulant aid for use herein typically has an amine modification degree of at least 0.1, at least 0.2, or at least 0.3, or at least 0.4, or at least 0.5, or at least 0.6, or at least 0.7, or at least 0.8, or at least 0.9, or at least 1.0. The modification degree is an indication of the amount of amine groups present in the polymeric material and is defined as the number ratio of the number of amine groups present in the polymeric material per monomer unit of the polymeric material. The coagulant aid may comprise a weight average molecular weight of at least 10,000, or at least 25,000, or at least 50,000, or at least 75,000, or at least 100,000.

The water treatment composition herein may comprise, by weight, from 0.1%, or from 0.5%, or from 1%, or from 1.5%, or from 2%, or from 2.5%, and to 50%, or to 40%, or to 30%, or to 20%_', or to 10%, or to 5%, or to 4% of a coagulant aid.

The water treatment composition may also comprise a bridging flocculant. The bridging flocculant may be substantially water-soluble at in-use concentrations and preferably has a weight average molecular weight of at least about 100,000 or at least about 2,000,000. The bridging flocculant may be selected on the basis that it can act as flocculent and cause the aggregation of water- insoluble particles into larger water- insoluble aggregated complexes known as floes. It is believed that the ability of the bridging flocculant to act as a flocculent, is due to the combination of its high molecular weight, structure, and water-solubility properties. The bridging flocculant is usually of greater molecular weight than the coagulant aid and optionally comprise an amine group. The bridging flocculant may comprise an amide group and/or a polyacrylamide. The bridging flocculant may exclude a cationic polyaerylanide, and the bridging flocculant may optionally be cationic. The bridging flocculant for use herein may be nonionic or anionic and may contain at least 0.02, or at least 0.05, or at least 0.1 anionic groups per monomer unit. The bridging flocculant for use herein is typically a polyacrylamide, such as for example, anionic or nonionic polyacrylamides.

A low amount of substantially water-soluble organic content may be present in the water treatment composition herein. The bridging flocculant may be substantially free of a polysaccharide and may be substantially free of a carboxymethyl cellulose or derivative thereof.

The weight average molecular weight of the bridging flocculant may be at least 2500000, or at least 3,000,000 or at least 5,000,000 or at least 7,500,000 or at least 10,000,000 or at least 15,000,000. The water treatment composition may comprise, by weight, from 0.1%, or from 0.2%, or from 0.5%, or from 1%, and to 30%, or to 20%, or to 10%, or to 5%, or to 3% of a bridging flocculant. The water treatment composition may comprise a microbiocidal disinfectant (sometimes referred to herein as the“disinfecting agent”). The disinfecting agent may comprise any compound which disinfects or sanitises water. The disinfecting agent may he inorganic such as silver salts, colloidal silver, nanosilver, ozone, chlorine dioxide, chlorine, sodium hypochlorite or chloramine. The disinfecting agent may also be organic such as a quaternary ammoniu compound or may include inorganic chlorine based disinfectants, wherein the chlorine is in a formal oxidation state that is not minus one, and may he above minus one. Sources of chlorine may comprise hypochlorites (such as calcium hypochlorite) and organic sources of chlorine such as isocyanurates. Other disinfecting agents may comprise iodine and sources of iodine such as polyiodide resins. As previously discussed, the disinfecting agent may be used in a controlled, delayed, sustained or slow release form. Means for providing such controlled, delayed, sustained or slow release (hereafter‘means for providing delayed release’ ) can include blending or coating the disinfecting agent with, for example, a poorly water-soluble or hydrophobic material, or providing a coating of sufficient thickness that the kinetics of dissolution of the coating provide delayed release. Poorly water-soluble or hydrophobic materials include waxes, paraffins, silicas, zeolites, clays, polymeric resins, celluloses, cross- linked polymers, insoluble salts such as calcium carbonate, etc. The coating material can be applied by agglomeration in, for example, pan, rotary’ drum and vertical blenders, or by spray atomization. Other means for providing delayed release include mechanical means for altering the physical properties of the disinfecting agent, for example, compaction, granulation means for altering the particle size distribution of the disinfecting agent, or the like.

To achieve improved levels of flocculation and disinfectancy performance in water contaminated with high levels of organic impurities, a disinfecting agent, such as calcium hypochlorite may be used wherein calcium hypochlorite may have a particle size distribution such that at least about 50%, preferably at least about 75%, preferably at least about 90% by weight is retained on a 210 pm (Tyler 65 mesh) screen, preferably on a 425 pm (35 mesh) screen, preferably on a 600 pm (28 mesh) screen, preferably on a 710 pm (24 mesh) screen, preferably on a 850 pm (20 mesh) screen, and preferably on a 1000 pm (16 mesh) screen. In order to minimise random sampling variance in the final unit dose composition, it is also preferred that the particulate disinfecting agent has a particle size distribution such that at least about 50%, preferably at least about 75% by weight thereof passes through a 2000 pm (9 mesh) screen and more preferably through a 1400 p (12 mesh) screen.

The water treatment composition preferably comprises (by weight) from 0.01%, or preferably from 0.1%, or preferably from 0.2%, or preferably from 0.5%, or preferably from 0 7%, or preferably from 1.0%, or preferably from 1.2%, or preferably from 1.5%, and preferably to 20%, or preferably to 10%, or preferably to 5%, or preferably to 4%, or preferably to 2.5% disinfecting agent.

The water treatment composition preferably comprises a water-insoluble silicate selected from clays, zeolites and mixtures thereof A technical effect of the water-insoluble silicate is to function as a seed particle onto which water-insoluble impurities can aggregate to form floes. As more floes are generated, this creates a larger area of matter for contacting the volatile compound thereby further reducing COD levels in the wastewater. Highly preferred silicates for use herein are clays. The clay acts as a seed particle onto which water-insoluble impurities can aggregate to form floes. The presence of clay in the composition improves the rate of floe formation and allows the formation of larger floes compared to when clay is absent from the composition herein. The clay may also act as a swelling agent, and if the composition herein is in the form of a tablet, the clay can improve the rate at which the tablet disintegrates on contact with water by swelling upon contact with water so that the components of the tablet are pushed apart by the swollen clay particles. The clay can also act as a desiccant within the tablet. The clay may also act as a cationic exchange agent to remove metal ions from the water and the clay can also remove colour, heavy metals and some organic material from water by adsorption. The clay is preferably a smectite clay, preferably a dioctahedral smectite clay such as montmorillonite clav or a trioctahedral smectite clav such as hectorite clay. Those clavs found in bentonite clay deposits are also preferred. Particularly preferred clays for use herein include laponite clay, hectorite, montmorillonite, nontronite, saponite, volkonsite, sauconite, beidellite, allevarlite, illite, halloysite and attapulgite. In compositions containing calcium hypochlorite, the free moisture content of the clay should be carefully controlled to provide acceptable disinfectant stability. Preferably the free moisture content should be less than about 4%, preferably less than about 3%, preferably less than about 2.5% and preferably less than about 1.5% by weight. Free moisture content is determined on a 2g sample of the test material following the procedure as described hereinabove.

Highly preferred to provide disinfectant stability are pre-dried clays which in their dessicated form have the potential to scavenge or pick up moisture. Such clays can be described in terms of their so-called‘water-capacity’ , defined herein as the equilibrium weight percentage of moisture picked up by a small sample (e.g. 10 mg) of the dessicated material from air at 80% relati ve humidity and 20° C. as measured by dynamic vapour sorption techniques. For example, if 10 mg of the dessicated clay picks up 2 mg moisture, the dessicated clay has a water capacity of 20%. Preferred for use herein are dessicated clays having a water capacity of at least about 10%, preferably at least about 15%, and more preferably at least about 18%.

The water treatment composition preferably comprises (by weight) from 1 %, or preferably from 5%, or preferably from 10%, or preferably from 15%, or preferably from 20%, or preferably from 25%, and preferably to 80%, or preferably to 50%, or preferably to 35% clay.

Aluminosilicates may be used herein in place of, or in addition to, clay. The aluminosilicate can act as a cationic exchange agent to remove metal ions from water, and can also act as a seed particle to enhance Hoc formation and as dessicant for enhancing disinfectant stability. Aluminosilicates for use herein may include zeolite A, zeolite X, zeolite Y, zeolite P and zeolite beta. The free moisture content of the aluminosilcate may be less than about 4%, less than about 3%, less than about 2.5% and less than about 1.5% by weight.

To improve disinfectant stability, pre-dried aluminosilicates which in their dessicated form may be used as they have the potential to scavenge or pick up moisture. Such dessicated aluminosilicates can also be described in terms of their so-called‘water-capacity’, as defined hereinabove. The dessicated aluminosilicates may have a water capacity of at least about 10%, may be at least about 15%, and may be at least about 18%. The composition herein may comprise (by weight) from 1%, or may be from 5%, or may be from 10%, or may be from 15%, or may be fro 20%, or may be from 25%, and may be to 80%, or alternatively to 50%, or alternatively to 35% aluminosilicate.

The water treatment composition may comprise a seed particle material that can act as a seed particle to enhance Hoc formation. The seed particle material is a polymeric material different from the coagulant aid and the bridging flocculant. The seed particle material does not contain an amine group and is substantially water insoluble. Thus, the seed particle material can be used in place of, or in addition to, clay or zeolite. The free moisture content of the seed particle material may be less than about 4%, alternatively less than about 3%, alternatively less than about 2.5% and alternatively less than about 1.5% by weight. The seed particle material may comprise cellulose, including and not limited to an unmodified cellulose, or powdered cellulose. The water treatment composition herein may comprise (by weight) from 1%, or from 5%, or from 10%, or from 15%, or from 20%, or from 25% , and to 80%, or to 50% , or to 35% of a seed particle material. The water treatment composition may comprise an alkali agent. The alkali agent can be any compound which gives alkalinity when contacted to water. The alkali agent for use herein is not a polymeric material. Providing the alkali agent in the water treatment composition facilitates generating an optimized pH in the wastewater to be treated. The water treatment composition herein preferably comprises an amount of alkali agent such that when the water treatment composition herein is contacted to water to form a solution, said solution has a pH of from 5 to 8, preferably from 6 to 7.

Preferred alkali agents are selected from the group consisting of sodium carbonate, sodium bicarbonate, sodium hydroxide, sodium oxide, calcium carbonate, calcium bicarbonate, calcium hydroxide, calcium oxide, potassium carbonate, potassium bicarbonate, potassium hydroxide, potassium oxide and combinations thereof.

Particular alkali agents which are a source of carbonate when contacted to water, for example sodium carbonate or sodium bicarbonate, may be preferred for used herein. If the water treatment composition herein comprises a source of acid, for example an inorganic salt such as iron sulphate, said alkali agent which is a source of carbonate can interact with said acid source in the presence of water to produce a gas. This process is known as effervescence, and may improve the rate at which the water treatment composition disperses, especially when the water treatment composition herein is in the form of a tablet. Highly preferred herein, especially in water treatment compositions containing calcium hypochorite as disinfecting agent, are alkalis which can also act as moisture sinks, especially anhydrous sodium carbonate. The water treatment composition herein typically comprises (by weight) from 1% to 50%, preferably from 10%, or preferably from 15%, or preferably from 20%, or preferably from 25%, and preferably to 45%, or preferably to 40%, or preferably to 35% alkali agent.

In the above description with reference to FIG. 1, the apparatus 10 may be a self- contained turnkey unit or a modular unit that is integrated with the system 100 in a manufacturing facility, and accordingly operation of the apparatus 10 may be configured to be fully automated to fit into the operation of the system 100. In another exemplary embodiment, such as shown in FIG. 3, the apparatus 10 may be configured as a modular and compact unit for deployment in other systems such as a system 300 for recovery of wastewater from a manufacturing process.

FIG. 3 is a schematic drawing of a system 300 for recovering of wastewater from a manufacturing process according to the present invention. The system 300 comprises an oil/water separator module 30 upstream of a wastewater treatment apparatus 10 and a post treatment module 40 downstream of the wastewater treatment apparatus 10. The oil/water separator module 30 includes an inlet chamber 32, an oil/water separation chamber 34 and an outlet chamber 36. The inlet chamber 32 may be connected to a feed line 301 through which wastewater from a manufacturing process enters the inlet chamber 32. The inlet chamber 32 may also be operatively connected to be in fluid connection with a container containing wastewater transported from a manufacturing and/or industrial facility which does not have the space to accommodate the system 300 onsite.

As shown in FIG. 3, the chambers 32, 34 and 36 are in fluid communication and may comprise baffles 302 arranged for separating oil 20 from wastewater in the separation chamber 34 and to allow wastewater with a reduced level of oil to enter the outlet chamber 36. An outlet line 303 is disposed in the outlet chamber 36 for discharging the wastewater for treatment by the wastewater treatment apparatus 10. The wastewater treatment apparatus 10 has substantially the same components as the wastewater treatment apparatus 10 of FIG. 1 but may differ in physical dimensions and arrangement of the components based on customization to be operatively connected with the corresponding components of the oil/water separator module 30 and the post-treatment module 40. Specifically, the outlet line 303 is arranged in fluid communication with first inlet 14 of the wastewater treatment apparatus 10.

In the water treatment apparatus 10, the wastewater is treated in the wastewater tank 13 according to the method 200 described hereinbefore and sludge is discharged through the first outlet 16 for disposal. In this way, the colloidal and suspended solids inside the wastewater can be completely removed through removal of the sludge. The water treatment composition added to the wastewater in the wastewater tank 10 may also include a microbiocidal disinfectant for disinfecting microorganisms. Treated wastewater discharged from the wastewater treatment apparatus 10 may be recycled or further processed in a post-treatment module 40 to further reduce a COD level in the treated wastewater.

Referring to FIG. 3, the post- treatment module 40 comprises a filtration housing 42 having an inlet 44 for receiving treated water from the wastewater treatment apparatus 10 and an outlet 46 for discharging suspended or colloidal particles. The filtration housing 42 comprises an inner chamber 48 for receiving and post-treating the treated wastewater entering from the wastewater treatment apparatus 10. Specifically, the filtration housing 42 comprises a barrier 50 arranged on a support 52 wherein the barrier 50 faces the inner chamber 44 and the support 48 faces away from the inner chamber 48. The barrier 50 is adjacent to the support 52 as a combined layered structure that may be disposed on opposing sides of the inner chamber 48 defining a width of the inner chamber 48. The support 52 may be made of a material including but not limited to non-woven fabric sheets to provide desired properties including high filtration rates and good mechanical strength.

The barrier 50 may be a membrane that acts as a filter for water to flow through and out through the support 52 while removing any residual suspended solids and other substances from wastewater in the inner chamber 48 and obtaining post-treated water. A technical effect of providing the water treatment apparatus 10 is that it minimizes clogging of the membrane with oil and water. Clogging of the membrane with oil and water may cause early mechanical failure of the post-treatment module 40 thereby increasing costs of equipment maintenance and replacement. The membrane may be semi-permeable membranes manufactured for use in water purification or water desalination systems. The semi-permeable membranes may include thin film composite membranes made out of a thin polyamide layer (<200 nm) deposited on top of a polyethersulfone or polysulfone porous layer (about 50 microns) on top of the support 52. The three-layer configuration gives the desired properties of high rejection of undesired materials (like salts), high filtration rate, and good mechanical strength. The polyamide top layer is responsible for the high rejection and is chosen primarily for its permeability to water and relative impermeability to various dissolved impurities including salt ions and other small, unfilterable molecules.

In an exemplary embodiment, the barrier 50 may comprise an absorbent material for absorbing volatile compounds. The barrier 50 may be a high porous aerogel such as a carbon- based aerogel, examples which are described in International Patent Publication WO 2015005868A1 published on 15 January 2015. In particular, as shown in Example II described hereinafter, where wastewater treated by the wastewater treatment apparatus 10 is post-treated by a post-treatment module 40 having a highly porous aerogel, COD levels of treated wastewater are further reduced by 48% because volatile compounds remaining in the treated wastewater (from the water treatment apparatus 10) are absorbed by the highly porous aerogel. A technical effect of using the highly porous aerogel is that the aerogel may be washed with water to remove volatile compounds such as aromatic oils absorbed in the aerogel and the aerogel may be reused again.

FIG. 4 is a process chart of a method 400 of recovery of wastewater from a manufacturing process. The method 400 comprises step 203 of discharging wastewater into a wastewater treatment apparatus 10 followed by step 204 in which a water treatment composition is added to the wastewater tank 13 of the wastewater treatment apparatus 10. Optionally, the method 400 may include steps 201 and 202 prior to step 203. It will be appreciated that the wastewater entering the wastewater treatment apparatus 10 (deployed in the system 300) may be wastewater from an earlier process of washing a processing tank 102 (such as shown in FIG. 1). Alternatively, the wastewater may have been pre-treated in an oil/water separator 30 to remove oil from the wastewater. The method 400 comprises treating wastewater in the wastewater treatment apparatus 10 according to the steps 204 and 205. The method 400 further comprises step 401 of contacting the treated wastewater from step 205 with a barrier 50 in the post-treatment module 40 to obtain post-treated wastewater, followed by step 402 of separating the post-treated wastewater from the barrier 50 to obtain post-treated wastewater. In step 401, oils from the treated wastewater is absorbed by the barrier 50 thereby resulting in post-treated wastewater. In step 402, the wastewater treated in the post-treatment module 40 may be separated the treated wastewater from the barrier 50. In an exemplary embodiment, where the barrier 50 is a membrane for water purification or desalination, the treated wastewater will be separated according to methods known in the water purification or desalination industries which will not be further described. In another exemplary embodiment, where the barrier 50 is a carbon-based aerogel such as a carbon fibre aerogel, the treated wastewater may be separated by the Carbon Fibre Aerogel Filtration Method described as follows;

1) Using a pump, the contaminated water is passed through the filtration housing 42 (as shown in FIG. 3) that contains a barrier 50 comprising a carbon fibre aerogel.

2) When the treated wastewater passes through the barrier 50, contaminants including organic compounds and/or oils are removed from the treated wastewater forming post- treated wastewater.

3) The relative percentage of organic compounds removed by the post-treatment module 40 can be determined by measuring a COD level of the post-treated wastewater discharged from the post-treatment module using the COD Test Method as described hereinbefore.

The post-treatment module 40 may be co-located with the wastewater treatment apparatus 10 (if the wastewater treatment apparatus 10 is used in-line with a manufacturing process) to enable treatment of wastewater and recovery of the treated wastewater in a single step, thereby reducing a level of contaminants in the wastewater and at the same time, eliminating the need for additional processing steps typically required for removing particles from the wastewater. As a result, the time required for wastewater treatment and treated wastewater recovery can be significantly reduced relative to conventional wastewater treatment and recovery processes. The post-treated wastewater may be returned to other processing tanks used in the manufacturing process to wash the other processing tanks thereby creating an alternative water supply for washing the processing tanks instead of using an external water source. However, it is also contemplated to have the wastewater tank 13 located at a different location from the processing tank 102. Such separate processes may be preferred when the manufacturing location does not have space for the additional wastewater tank 13 and/or if a separate process for treating the wastewater is desirable for other reasons, such as, for example, when the treatment process is faster than or slower than the manufacturing process, where a separate group or company is handling the wastewater treatment and/or when it is preferred to treat the wastewater at a different time than when it is generated.

Further, the post-treated wastewater may be directed to a sewer system or directed to further treatment. The further treatment may include known water treatment technologies including physical and chemical water treatment processes. Chemical water treatment processes may include a chemical treatment including but not limited to addition of halogens or oxidants such as ozone, or chlorination to provide disinfection. Physical water treatment processes may include a physical treatment including but not limited to filtration treatment including filtration by media such as sand or by a membrane designed for nanofiltration, microfiltration, ultrafiltration or reverse osmosis; heat treatment including evaporation, air treatment including aeration or deaeration; radiation including ultraviolet radiation; acoustic treatment; electrodeionisation; capacitive deionization; combinations thereof. TEST EQUIPMENT/MATERIALS

Equipment and materials used for each of the Examples set forth herein are listed in Table 1 below. Comparative and Inventive Samples used for testing in the Examples are described under the respective Examples.

Table 1

TEST METHODS

Carbon Oxygen Demand (COD) Level Test Method

The COD Level Test Method determines the quantity of oxygen required to oxidize the organic matter in a wastewater sample, under specific conditions of oxidizing agent, temperature, and time. Organic and oxidizable inorganic substances in the sample are oxidized by potassium dichromate in 50% sulfuric acid solution at reflux temperature. Silver sulfate is used as a catalyst and mercuric sulfate is added to remove chloride interference. The excess dichromate is titrated with standard ferrous ammonium sulfate, using orthophenanthroline ferrous complex as an indicator.

COD level of a Sample is measured according to the following steps:

1. Pre-heat the COD Test Tube Heater to l50°C.

2. Remove a cap from a COD Test Tube.

3. Add 2 ml of a Sample to the COD Test Tube, while keeping the COD Test Tube at a 45 -degree angle.

4. Replace the cap of the COD Test Tube. Rinse the outside of the COD Test Tube with deionized water and wipe the COD Test Tube clean with a paper towel.

5. Hold the COD Test Tube by the cap and over a sink. Invert gently several times to mix the contents.

6. Place the COD Test Tube in the pre-heated COD Test Tube Heater.

7. Prepare a Blank COD Test Tube by repeating Steps 2 to 6 substituting 2.00 mL deionized water for the Sample.

8. Heat the COD Test Tube with the Sample and the Blank COD Test Tube for 2 hours.

9. Turn off the COD Test Tube Heater. Wait for about 20 minutes for the COD Test Tubes to cool to a temperature less than or equal to l20°C. 10. Invert each COD Test Tube several times while still warm. Place the COD Test Tubes into a rack and wait until the COD Test Tubes have cooled to ambient temperature.

11. Measure the COD of the Sample in the COD Test Tube using the COD Multiparameter Laboratory Photometer.

pH Measurement Test Method

A pH level of a Sample is tested according to the following steps:

1. Collect 100 ml of a Sample;

2. Measure the pH of the Sample using the pH Mettler Toledo meter. Record the pH reading for the Sample.

Water Insolubility Test. Method

W'ater insolubility of a material is tested according to the following steps:.

1) 1 g material is added to 1 litre of distilled water at a pH of between 6.0 and 8.0, at 20° C. and stirred vigorously for 24 hours.

2) The water is then filtered through a 3 micrometer filter, and the undissolved material which is collected by the filter step is dried at 80° C. until constant weight, typically for 24 to 48 hours.

3) The weight of this undissolved material is then determined and the % dry weight of this undissolved material can be calculated.

Water Solubility Test Method

The term“substantially low amount of water-soluble content” and can be determined according to the following steps:

1 ) 500 mg of said water treatment composition is added to 1 litre of deionised water which comprises no detectable amounts of substantially water-soluble organic content, to form a solution.

2) Said solution is left with occasional stirring for 30 minutes and is then filtered through Whatman GF/C paper having an average pore size of 1.2 micrometers to obtain treated water.

3) The level of total organic content (TOC) of the treated water is determined using the ISO method 8245:1999.

A low amount of substantially water-soluble organic content may be obtained on use of the water treatment composition either in-vivo or on model surface water. For this purpose, 620 mg of the water treatment composition is added to 1 litre of in-vivo or model surface water respectively and the test repeated. The TOC of the water after treatment may be less than 10 ppm, more preferably less than 7 ppm, and especially less than 4 ppm. EXAMPLES

EXAMPLE I

Example I demonstrate an effect of treating wastewater according to a method for reducing the level of contaminants in wastewater from a manufacturing process according to the present invention. Wastewater Lots A, B and C for preparing Comparative and Inventive Samples A, B and C are described in Table 2 below'.

Table 2

The Comparative and Inventive Samples A, B and C are prepared at ambient temperature ranging from 20°C to 25°C. Comparative Samples A, B and C are prepared according to the following steps:

(i) Mix Wastewater Lots A, B and C respectively for 5 minutes at RPM 700 using a Mettler Toledo Mixing Scale

(ii) Weigh 20,000 g of Wastewater Lots A, B, C respectively into three separate 2000 ml beakers and mix the beakers for 5 minutes at RP 700 using the Mettler Toledo Mixing Scale;

(iii) Transfer 200 g of Wastewater Lots A, B, C respectively into separate bottles of 250 ml and labeled as Comparative Samples A, B and C respectively;

(iv) Measure pH of each of the Comparative Samples A, B and C respectively.

Inventive Samples A, B and C are prepared according to the following steps:

(i) Transfer 2000 g of wastewater from Wastewater Lots A, B and C respecti vely into three separate 2000 ml beakers;

(ii) Add 4 grams of a water treatment composition comprising iron sulfate into each beaker and mix the beakers for 5 minutes at 700 RPM using the Mettler Toledo Mixing Scale;

(iii) Filter the treated wastewater into three separate 2000 ml beakers

(iv) Transfer 200 g of the treated wastewater respectively into separate 250 ml bottles and label as Inventive Samples A, B and C respectively; (v) Measure pH of each of the Inventive Samples A, B and C respectively.

The COD of the Samples are measured according to COD Test Method as described hereinbefore. Table 3 shows the COD and pH measurements of the Samples.

Table 3

EXAMPLE II

Example II demonstrate an effect of treating wastewater according to a method for reducing the level of contaminants in wastewater from a manufacturing process wherein the method further comprises treating wastewater treated by the water treatment composition with a post-treatment module 40 (shown in FIG. 3) in which the barrier material 50 is a highly porous aerogel as specified hereinbefore.

Inventive Sample AA is prepared and treated according to the following steps:

(i) Transfer 2000 g of wastewater from Wastewater Lot A into a 2000 ml beaker;

(ii) Add 4 grams of a water treatment composition comprising iron sulfate into the beaker and mix the beaker for 5 minutes at 700 RPM using the Mettler Toledo Mixing Scale;

(in) Filter the treated wastewater into a 2000 ml beaker

(iv) Transfer 200 g of the treated wastewater into a 250ml bottle and label as Inventive Sample AA;

(v) Pass Inventive Sample A through the post-treatment module;

(vi) Collect treated water from step (v).

The COD of the Inventive Sample AA is measured according to COD Test Method as described hereinbefore. Table 4 shows the COD and pH measurements of Inventive Sample A A with Comparative and Inventive Samples A to show' the improvement in the reduction of COD levels of the wastewater.

Table 4

The COD measurement for Inventive Sample AA show that the combination of steps of treating wastewater with the water treatment composition and passing the treated wastewater through a post-treatment module further reduces the COD level of the treated water to 1320 (i.e. by 48% relative to Inventive Sample A). The COD levels are further reduced because volatile compounds remaining in the treated wastewater are absorbed by the aerogel. In view of the above results, almost complete removal of the COD in wastewater could be obtained on passage of the treated wastewater through a single larger post-treatment module or a plurality of small post-treatment modules in a series.

Additional examples are described below:

A. A method for reducing the level of contaminants in wastewater from a manufacturing process, the method comprising the steps of;

(i) feeding water into a processing tank that has been used to process one or more materials having negatively charged particles that become contaminants in wastewater;

(ii) washing the processing tank with the water, wherein the water becomes mixed with the contaminants forming wastewater;

(iii) discharging the wastewater into a wastewater tank;

(iv) adding a water treatment composition to the wastewater tank, the water treatment composition comprising a coagulant selected from the group consisting of: one or more water-soluble multi-valent inorganic salts and mixtures thereof, wherein the coagulant attracts and neutralizes the negatively charged particles in the wastewater to form insoluble matter; and

(v) removing the insoluble matter to obtain treated wastewater with a reduced level of contaminants.

B. The method according to A, wherein the contaminants comprise volatile liquids selected from the group consisting of: aromatic oils and liquid hydrocarbons. C. The method according to A or B, wherein the one or more water-soluble multi-valent inorganic salts are selected from the group consisting of: iron sulphate, iron chloride, manganese sulphate, manganese chloride, copper sulphate, copper chloride, aluminium sulphate, aluminium chloride, poly- variations thereof, and combinations thereof.

D. The method according to A, B or C, wherein the water treatment composition comprises an alkali agent selected from the group consisting of: sodium carbonate, sodium bicarbonate, sodium hydroxide, sodium oxide, calcium carbonate, calcium bicarbonate, calcium hydroxide, calcium oxide, potassium carbonate, potassium bicarbonate, potassiu hydroxide, potassiu oxide and combinations thereof.

E. The method according to D, wherein the alkali agent is a carbonate source selected from the group consisting of: sodium carbonate, sodium bicarbonate, calcium carbonate, calcium bicarbonate, potassium carbonate, potassium bicarbonate and combinations thereof.

F. The method according to A, B, C, D, or E, wherein the water treatment composition comprises one of: the coagulant, a bridging flocculant and a coagulation aid, in amounts by weight of the wastewater configured to obtain a carbon oxygen demand (COD) reduction percentage of at least 30% of an initial COD level in the wastewater.

G. The method according to A, B, C, D, E or F, wherein the water treatment composition comprises a water-insoluble silicate selected from clays, zeolites and mixtures thereof.

H. The method according to A, B, C, D, E, F or G, wherein the step (iii) comprises adding the water treatment composition in an amount of at least 400 ppm by weight of the wastewater.

I. The method according to A, B, C, D, E, F, G or H, further comprising the step of:

(vi) returning at least a portion of the treated wastewater from step (v) to the processing tank of step (i).

J. The method according to I, wherein the at least portion of the treated wastewater returned to the processing tank is run through the process steps (i)-(vi) two or more times. K. A wastewater treatment apparatus for reducing the level of contaminants in wastewater from a manufacturing process, the device comprising

a wastewater tank comprising:

i. a first inlet for receiving wastewater from the manufacturing process, the wastewater comprising a mixture of water and contaminants having negative charged particles;

ii. a second inlet arranged for receiving a water treatment composition; and iii. a first outlet;

wherein the water treatment composition comprising a coagulant selected from the group consisting of: one or more water-soluble multi- valent inorganic salts and mixtures thereof, wherein the coagulant attracts and neutralizes the negatively charged particles in the wastewater to form insoluble matter to be discharged through the first outlet of the wastewater tank.

L. The apparatus according to K, wherein the wastewater tank further comprises a second outlet configured for fluid connection with a wastewater supply feedline of a manufacturing process for returning treated wastewater remaining in the wastewater tank to a processing tank of the manufacturing process.

M. A method of recovering wastewater from a manufacturing process, the method comprising the steps of;

(iii) discharging the wastewater into a wastewater tank;

(iv) adding a water treatment composition to the wastewater tank, the water treatment composition comprising a coagulant selected from the group consisting of: one or more water-soluble multi-valent inorganic salts and mixtures thereof, wherein the coagulant attracts and neutralizes the negatively charged particles in the wastewater to form insoluble matter;

(v) removing the insoluble matter to obtain treated wastewater with a reduced level of contaminants; (vi) contacting the treated wastewater with a barrier having an absorbent material for absorbing volatile compounds to obtain post-treated wastewater; and

(vii) separating the post-treated wastewater in step (vi) from the barrier.

N. The method according to M, wherein the treated wastewater is passed through the barrier and the barrier acts to filter the volatile compounds from the treated wastewater.

O. The method according to M, wherein the post-treated wastewater is returned to the processing tank of step (i).

P. The method according to M, wherein the post-treated wastewater is directed to a sewer system.

Q. The method according to M, wherein the post-treated wastewater is directed to further treatment.

R. The method according to M, wherein the one or more water-soluble multi-valent inorganic salts are selected from the group consisting of: iron sulphate, iron chloride, manganese sulphate, manganese chloride, copper sulphate, copper chloride, aluminium sulphate, aluminium chloride, poly- variations thereof, and combinations thereof.

S. The method according to M, wherein the water treatment composition comprises one of: the coagulant, a bridging flocculant and a coagulation aid, in amounts by weight of the wastewater configured to obtain a carbon oxygen demand (COD) reduction percentage of at least 30% of an initial COD level in the treated wastewater of step (v).

T. The method according to M, wherein the water treatment composition comprises one of: a water-insoluble silicate selected from clays, zeolites and mixtures thereof; and a microbiocidal disinfectant for disinfecting microorganisms.

The dimensions and values disclosed herein are not to be understood as being strictly limited to the exact numerical values recited. Instead, unless otherwise specified, each such dimension is intended to mean both the recited value and a functionally equivalent range surrounding that value. For example, a dimension disclosed as“40 mm” is intended to mean “about 40 mm.”

Every document cited herein, including any cross referenced or related patent or application and any patent application or patent to which this application claims priority or benefit thereof, is hereby incorporated herein by reference in its entirety unless expressly excluded or otherwise limited. The citation of any document is not an admission that it is prior art with respect to any invention disclosed or claimed herein or that it alone, or in any combination with any other reference or references, teaches, suggests or discloses any such invention. Further, to the extent that any meaning or definition of a term in this document conflicts with any meaning or definition of the same term in a document incorporated by reference, the meaning or definition assigned to that term in this document shall govern.

While particular embodiments of the present invention have been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of this invention.

Claims

What is claimed is:

1. A method for reducing the level of contaminants in wastewater from a manufacturing process, the method comprising the steps of:

(i) feeding water into a processing tank that has been used to process one or more materials having negatively charged particles that become contaminants, preferably, volatile liquids selected from the group consisting of: aromatic oils and liquid hydrocarbons, in wastewater;

(iii) discharging the wastewater into a wastewater tank;

(iv) adding a water treatment composition to the wastewater tank, the water treatment composition comprising a coagulant selected from the group consisting of: one or more water-soluble multi- valent inorganic salts and mixtures thereof, wherein the coagulant attracts and neutralizes the negatively charged particles in the wastewater to form insoluble matter; and

2. The method according to claim 1, wherein the one or more water-soluble multi- valent inorganic salts are selected from the group consisting of: iron sulphate, iron chloride, manganese sulphate, manganese chloride, copper sulphate, copper chloride, aluminium sulphate, aluminium chloride, poly- variations thereof, and combinations thereof.

3. The method according to any preceding claim, wherein the water treatment composition comprises an alkali agent selected from the group consisting of: sodium carbonate, sodium bicarbonate, sodium hydroxide, sodium oxide, calcium carbonate, calcium bicarbonate, calcium hydroxide, calcium oxide, potassium carbonate, potassium bicarbonate, potassium hydroxide, potassium oxide and combinations thereof, preferably the alkali agent is a carbonate source selected from the group consisting of: sodium carbonate, sodium bicarbonate, calcium carbonate, calcium bicarbonate, potassium carbonate, potassium bicarbonate and combinations thereof.

4. The method according to any preceding claim, wherein the water treatment composition comprises one of: the coagulant, a bridging flocculant and a coagulation aid, in amounts by weight of the wastewater configured to obtain a carbon oxygen demand (COD) reduction percentage of at least 30% of an initial COD level in the wastewater.

5. The method according to any preceding claim, wherein the water treatment composition comprises a water-insoluble silicate selected from clays, zeolites and mixtures thereof.

6. The method according to any preceding claim, wherein the step (iii) comprises adding the water treatment composition in an amount of at least 400 ppm by weight of the wastewater.

7. The method according to any preceding claim, further comprising the step of:

8. The method of claim 7, wherein the at least portion of the treated wastewater returned to the processing tank is ran through the process steps (i)-(vi) two or more times.

9. A wastewater treatment apparatus for reducing the level of contaminants in wastewater from a manufacturing process, the device comprising:

a wastewater tank comprising:

wherein the water treatment composition comprising a coagulant selected from the group consisting of: one or more water-soluble multi-valent inorganic salts and mixtures thereof, wherein the coagulant attracts and neutralizes the negatively charged particles in the wastewater to form insoluble matter to be discharged through the first outlet of the wastewater tank.

10. The apparatus according to claim 9, wherein the wastewater tank further comprises a second outlet configured for fluid connection with a wastewater supply feedline of a manufacturing process for returning treated wastewater remaining in the wastewater tank to a processing tank of the manufacturing process.

11. A method of recovering wastewater from a manufacturing process, the method comprising the steps of:

(iii) discharging the wastewater into a wastewater tank;

(iv) adding a water treatment composition to the wastewater tank, the water treatment composition comprising a coagulant selected from the group consisting of: one or more water-soluble multi- valent inorganic salts and mixtures thereof, wherein the coagulant attracts and neutralizes the negatively charged particles in the wastewater to form insoluble matter;

(v) removing the insoluble matter to obtain treated wastewater with a reduced level of contaminants;

(vi) contacting the treated wastewater with a barrier having an absorbent material for absorbing volatile compounds to obtain post-treated wastewater; and

(vii) separating the post-treated wastewater in step (vi) from the barrier.

12. The method according to claim 11, wherein the treated wastewater is passed through the barrier and the barrier acts to filter the volatile compounds from the treated wastewater.

13. The method according to claim 11 or claim 12, wherein the post-treated wastewater is returned to the processing tank of step (i), preferably the post- treated wastewater is directed to a sewer system or to further treatment.

14. The method according to any one of claims 11 to 13, wherein the one or more water- soluble multi-valent inorganic salts are selected from the group consisting of: iron sulphate, iron chloride, manganese sulphate, manganese chloride, copper sulphate, copper chloride, aluminium sulphate, aluminium chloride, poly- variations thereof, and combinations thereof.

15. The method according to any one of claims 11 to 14, wherein the water treatment composition comprises one of: the coagulant, a bridging flocculant and a coagulation aid, in amounts by weight of the wastewater configured to obtain a carbon oxygen demand (COD) reduction percentage of at least 30% of an initial COD level in the treated wastewater of step (v), preferably, the water treatment composition further comprises one of: a water-insoluble silicate selected from clays, zeolites and mixtures thereof; and a microbiocidal disinfectant for disinfecting microorganisms.