GB2483527A

GB2483527A - Surface reactor

Info

Publication number: GB2483527A
Application number: GB1104541.6A
Authority: GB
Inventors: Galen Yarrow Fulford
Original assignee: BIOMATRIX WATER TECHNOLOGY LLP
Current assignee: BIOMATRIX WATER TECHNOLOGY LLP
Priority date: 2010-09-13
Filing date: 2011-03-17
Publication date: 2012-03-14
Anticipated expiration: 2031-03-17
Also published as: GB2483527B; GB201104541D0; GB201015134D0

Abstract

A surface reactor 1a suitable for the treatment of a contaminated water body comprises a hollow structural cover 3 mounted on a buoyant flotation support 4 and an aerator 5. The aerator is housed within the hollow structural cover. Preferably, the cover comprises a growth medium 6 possessing one or more layers. The cover acts to contain contaminant carrying aerosols typically associated with mechanical aerators and also allows filtered air to pass through planted media 9, replacing and replenishing oxygen diffused by the aerator and providing a filter to malodorous gasses released in the aeration process. The aerator may be a surface or sub-surface aerator. The one or more layers of the growth medium can be a supporting layer, a moisture conveying or wicking substrate, an organic lignin based fibrous matting or a fibre reinforced soil. Typically, the reactor further comprises an anchoring system 12, a power supply provided by either a renewable energy source (7, Fig. 2) or a power line connected to a mains supply, a bio-augmentation device (13, Fig. 5), an ammonia probe (14, Fig. 5) adapted for communication with the bio-augmentation device and a sub-surface growth medium 10.

Description

I Surface Reactor 3 The present invention relates to the field of water treatment. More specifically, the present 4 invention concerns a surface reactor suitable for the treatment of water in a lagoon, reactor vessel, canal, lake, river or the like.

7 Many water bodies, for example lakes, ponds, canals, estuaries, lagoons, treatment 8 containments, and rivers are contaminated with sewage, industrial waste water and storm 9 water runoff as well as other pollutants. The result of these pollution loads contributes to eutrophication, decreasing the levels of dissolved oxygen, loss of biodiversity and 11 decreasing water quality both in the water body to be treated and its receiving water body.

13 To date many methods of treatment have been employed, including: 14 1) aeration; 2) inoculation with bacteria, or chemical treatments; and 16 3) passive re-vegetation and natural methods such as phytoremediation.

18 These approaches are somewhat limited due to a number of factors.

1 Where aeration techniques are applied this generally takes the form of employing fine 2 bubble membrane diffusers or mechanical aeration units. In open environments fine 3 bubble diffusers are subject to clogging and mechanical aeration units create fine particles 4 of water droplets in the air (Aerosols) causing the potential spread of water borne illnesses.

7 Inoculation with bacteria, as with treatment through chemical processes, has typically been 8 limited by the requirement for frequent reapplication of the desired bacteria or chemical 9 treatment.

11 Passive re-vegetation and phyto-remediation is a useful element of water treatment 12 however its capacity is limited by the slow reaction rates associated with such passive 13 natural systems.

It is therefore an object of an aspect of the present invention to obviate or at least mitigate 16 the foregoing disadvantages of the water treatment apparatus known in the art for the 17 treatment of a contaminated water body.

1 Summary of Invention

3 According to a first aspect of the present invention there is provided a surface reactor 4 suitable for the treatment of a contaminated water body, the reactor comprising a hollow structural cover mounted upon a buoyant floatation support and an aerator wherein the 6 aerator is housed within the hollow structural cover.

8 The above arrangement provides a surface reactor wherein the hollow structural cover 9 significantly reduces the noise and effects of aerosols produced by the aerator thus making the apparatus more flexible with respect to the areas within which it may be 11 deployed. For example, such a surface reactor may be installed in close proximity to 12 dwellings or work spaces.

14 A mechanical aeration unit, which may be a surface aerator or a submersed or sub-surface aerator, may be utilised.

17 Optionally, the hollow structural cover comprises a growth medium, optionally an 18 ecological growth medium, comprising one or more layers. Inclusion of the ecological 19 growth medium acts to further reduce the noise and effects of aerosols produced by the aerator. This medium also provides a more attractive visual appearance to the reactor 21 again allowing it to be deployed in a greater number of locations.

23 The one or more layers may comprise one or more layers selected from the group 24 comprising a supporting layer, a moisture conveying or moisture wicking substrate, an organic lignin based fibrous matting, a fibre re-enforced soil of peat or bark or compost, a 26 moisture retaining layer, and a particulate filtration layer.

28 Such a layer selection may provide additional benefit through biofiltration of malodorous 29 gasses (such as hydrogen sulphide, ammonia, and mercaptons) and the like released inside the cover as the water being treated undergoes transition from anaerobic or anoxic 31 to aerobic conditions.

33 The surface reactor may further comprise an anchoring system. This provides a movable 34 fixing system allowing the reactor to be easily relocated or repositioned.

1 The surface reactor preferably comprises a power supply. Optionally the power supply 2 comprises a renewable energy source, e.g. solar panels or wind turbines. Alternatively, 3 the power source comprises a power line connected to a mains supply.

Optionally the surface reactor further comprises one or more electronic sensory probes.

6 The electronic sensory probes provide a means for monitoring oxygen levels within the 7 water body.

9 The surface reactor may also comprise a bio-augmentation device. Such a device allows for additional inoculation with beneficial bacteria, for specific remediation purposes such as 11 nitrification with nitrosanomas, nitrobactor, or other bacteria for the reduction of fats, oils 12 and grease. In such an embodiment the surface reactor may comprise an ammonia probe 13 adapted for communication with the bio-augmentation device.

The surface reactor may also comprise a subsurface growth medium. This medium 16 provides a means for increasing treatment biomass volume and surface area.

18 The surface reactor may also comprise one or more floating extensions, said extensions 19 preferably supporting additional planted or un-planted surfaces or any suitable subsurface biofilm media, or the like.

1 Brief Description of Drawings

3 Aspects and advantages of the present invention will become apparent upon reading the 4 following detailed description and upon reference to the following drawings in which: 6 Figure 1 presents a perspective view of a surface reactor located within a river estuary in 7 accordance with an embodiment of the present invention; 9 Figure 2 presents a cross sectional side view of the surface reactor of Figure 1; 11 Figure 3 presents a side view of a surface reactor in accordance with an alternative 12 embodiment of the present invention; 14 Figure 4 presents a cross sectional side view of the surface reactor of Figure 3; 16 Figure 5 presents a side view of a surface reactor in accordance with an alternative 17 embodiment of the present invention; 19 Figure 6 presents a cross sectional perspective view of the surface reactor of Figure 5; and 22 Figure 7 presents a cross sectional side view of a surface reactor in accordance with an 23 alternative embodiment of the present invention.

1 Detailed Description

3 A surface reactor 1 will now be described by referring to the accompanying drawings.

A first embodiment of the present invention will now be described with reference to Figures 6 1 to 4. In particular Figure 1 presents a perspective view and Figure 2 a cross sectional 7 side view of the surface reactor 1 a located within a river estuary 2. Similarly, Figure 3 8 presents a bottom perspective view of a surface reactor Ia while Figure 4 presents a cross 9 sectional side view of the surface reactor I a.

11 The surface reactor 1 a can be seen to comprise a hollow structural cover 3 mounted upon 12 a buoyant floatation support 4 and an aeration unit 5 that is housed within the hollow 13 structural cover 3. An ecological growth medium or bio-filter 6 is formed upon/within the 14 hollow structural cover 3 and covers substantially all of its surface area. The ecological growth medium 6 comprises one or more layers selected from the group comprising a 16 supporting layer, an organic lignin based fibrous matting, a media (such as fibre re- 17 enforced soil) of organic or lignin content and a moisture conveying or moisture wicking 18 substrate.

Located on a top surface of the surface reactor 1 a may be a renewable energy source 7 21 e.g. a wind turbine or a plurality of solar panels (shown figuratively in Figure 2). This 22 renewable energy source 7 is employed to generate the required energy to power the 23 components of the surface reactor Ia, e.g. the aeration unit 5. Alternatively the energy 24 supply to the surface reactor Ia may be via power lines connected to a mains supply.

26 The aeration unit 5 may be of any suitable commercial aeration unit; the AQUA TURBO® 27 AER-AS produced by Aquasystems International NV being one such suitable example.

29 The surface reactor Ia may comprise one or more electronic sensory probes 8 (as illustrated in Figure 7, for example) that provide a means for monitoring the oxygen levels 31 within the water body.

33 An alternative embodiment of the surface reactor I b is presented in Figures 5 and 6. In 34 particular Figure 5 presents a side view of the surface reactor I b provided with extensions while Figure 6 presents a cross sectional perspective view of the surface reactor Ib, again 1 showing the extensions. The surface reactor 1 b shares many of the elements previously 2 described with reference to the surface reactor la, as indicated by the same reference 3 numerals. In this embodiment, as with the previous embodiment, a layer of plants or 4 vegetation 9 can be seen to be growing out of the top surface of the hollow structure cover 3.

7 Figure 7 presents a cross sectional side view of a further alternative embodiment of the 8 surface reactor Ic. As illustrated, and in contrast to the previously described 9 embodiments, this embodiment does not comprise a planted surface.

11 The surface reactor 1 c shares many of the elements previously described with reference 12 to the surface reactor la and Ib, as indicated by the same reference numerals. In this 13 embodiment the surface reactor Ic can be seen to further comprise: 14 * a subsurface growth medium 10 SO as to increase a means for increasing the treatment biomass volume and surface area; 16 * a flotation 11 upon which may be mounted further plants or vegetation 17 * an anchoring system 12 that provides a movable fixing system allowing the surface 18 reactor Ic to be easily relocated or repositioned; 19 * a bio-augmentation device 13 which allows for additional inoculation with beneficial bacteria, for specific remediation purposes such as nitrification with nitrosanomas, 21 nitrobactor, or reduction of fats oils and grease; 22 * an ammonia probe 14 adapted for communication with the bio-augmentation 23 device.

The water flow induced by the aeration unit 5 is also represented in Figure 7 by the solid 26 arrows.

28 Note that while the embodiment illustrated in Figure 7 clearly does not comprise a planted 29 surface, it will be understood by the skilled person that Figure 7 is also illustrative of a yet further alternative embodiment of a like surface reactor prior to plant growth. Further 31 alternatively, it will be readily understood that the cover may comprise portions that are 32 planted and portions that are un-planted.

34 The described surface reactors I a, I b and 1 c exhibit a number of key advantages over those systems known in the art.

2 In the first instance the buoyant flotation support 4 allows the surface reactors Ia, lb and 3 1 c to be deployed on the water body without the need for fixed structural supports. This 4 component also facilitates a dynamic response to changing water levels associated with bioremediation and treatment applications with intermittent flow conditions.

7 The hollow structural cover 3 provides a means for containing contaminant carrying 8 aerosols, typically associated with mechanical aeration equipment (such as aeration unit 5, 9 or other aeration devices or processes which may present or produce odours). This component also allows for filtered air to pass through planted media 9 (where present), 11 replacing and replenishing oxygen diffused by the aeration equipment 5 and providing a 12 primary filter, to malodorous gasses potentially released in the aeration process.

14 It is found that the delivery of air to the water by surface aeration can be as much as twice as energy end performance efficient as shallow water subsurface mechanical aeration 16 devices employed for similar purposes. Employing a surface aerator 5 thereby 17 significantly reduces the energy requirements of the surface reactors Ia, lb and Ic and 18 thus the associated operational costs.

The multilayered ecological growth media 6 supports a diverse colon isation with beneficial 21 bacteria as an integral element in the water treatment process. The media can be fully 22 drained through the pores contained therein thus maintaining an aerobic environment.

23 Moisture accumulating in the media is transferred through perforations in the hollow 24 structural cover 3 so as to allow contact with the beneficial bacteria colonising the roots of the covering plants (where present). The optional feature of a planted surface (as 26 illustrated, for example, in Figures 1 to 6 by reference numeral 9) facilitates the growth of a 27 diverse community of organisms within the surface reactors I a, I b and I c which thrive on 28 the plants roots and which are adapted to utilize food and energy sources within the 29 contaminated water system. The establishment and growth of these ecologies within the surface reactors Ia, lb and Ic provide a continuous self-sustaining inoculation of 31 beneficial organisms into the treatment reactor volume, and a subsequent increase in 32 efficiency and range of contaminants which may be reduced and treated.

34 The multilayered ecological growth media 6 provides a second important filtration process i.e. trapping and containing aerosols and providing a primary filtering of malodorous 1 gasses released in the treatment process which typically include hydrogen suiphides, 2 mercaptons and ammonia. Malodorous gasses are absorbed by organic compounds in 3 the media, and consumed by the bacteria which thrive within the media layers. Higher 4 plants 9 (if present) play an important role in maintaining the bacterial colonies and available carbon content through carbohydrates and enzymes exuded from their root 6 mass.

8 The anchoring system 12 provides a movable fixing system allowing the surface reactors 9 1 a, I b and I c to be relocated or repositioned if treatment conditions change or require a re-configuration of the system or change in spacing or density of reactors.

12 Surface reactors installed for waste-water treatment or bioremediation purposes provide a 13 natural look and the whole water ecosystem effect has a significant advantage over 14 traditional bioremediation or open mechanical aeration systems. This is important in allowing treatment in waterways that receive significant amounts of human waste water, 16 and in some water treatment plants which require control of odours and aesthetics.

18 Surface reactors may, for example, be deployed within a water area which is periodically 19 subject to combined sewage overflow or storm drain discharge. The deployed surface reactors, or variations thereof, will adopt a well covered natural look, with contained 21 odours, equipment and noise, while at the same time providing a powerful treatment 22 process reducing pollution and protecting the environment.

24 Surface reactors may also be applied in locations where waste water, is desired for re-use purposes, and a cost effective, low impact treatment is required. It may also be applied in 26 bioremediation purposes and for retrofitting in existing treatment works.

28 The covering elements 3, 6 and (optionally) 9 act to eliminate noise, typically associated 29 with mechanical aeration equipment 5. lt can also provide an attractive visual appearance, similar to that of natural vegetated island, allowing this type of treatment to be applicable to 31 many more locations than would otherwise be acceptable for treatment equipment, and 32 allowing installation in closer proximity to homes and business not previously acceptable 33 due to the aforementioned disadvantages.

1 The foregoing description of the invention has been presented for purposes of illustration 2 and description and is not intended to be exhaustive or to limit the invention to the precise 3 form disclosed. The described embodiments were chosen and described in order to best 4 explain the principles of the invention and its practical application to thereby enable others skilled in the art to best utilise the invention in various embodiments and with various 6 modifications as are suited to the particular use contemplated. Therefore, further 7 modifications or improvements may be incorporated without departing from the scope of 8 the invention herein intended.