GB2524511A

GB2524511A - Waste water treatment apparatus

Info

Publication number: GB2524511A
Application number: GB1405285.6A
Authority: GB
Inventors: Declan Mcshane
Original assignee: DMAC ENVIRONMENTAL Ltd
Current assignee: DMAC ENVIRONMENTAL Ltd
Priority date: 2014-03-25
Filing date: 2014-03-25
Publication date: 2015-09-30
Also published as: GB201405285D0; IE20150066A1

Abstract

A waste water treatment apparatus comprises a first treatment stage for removing solid contamination from the waste water, a second treatment stage for removing oil and other immiscible low specific gravity contaminants from the waste water, and a third treatment stage, wherein the waste water is aerated to create optimum conditions for microbial decomposition of contaminants within the waste water. The apparatus preferably comprises a housing or tank 2 having a base 4, a pair of side walls 6, 8 extending upwardly from said base and a pair of end walls 10, 12 extending upwardly from said base to extend transversely between said side walls, and at least one dividing wall 14, 16 extending between said side walls to divide said housing or tank into a plurality of chambers. A respective one of the water treatment stages is accommodated in each of said plurality of chambers, wherein the waste water passes through the plurality of chambers consecutively from an upstream chamber to a downstream chamber. The first treatment stage can comprise a vessel containing filtration media. The apparatus may be used for treating waste water from a washing facility.

Description

Waste Water treatment apparatus This invention relates to a waste water treatment apparatus for treating waste water from a washing facility.

In many applications water is used to wash objects or materials, resulting in a waste water run off carrying considerable amounts of entrained solids and dissolved or suspended contaminants. Such waste water run off can pose problems for disposal. When water is used as a washing medium in industrial or automotive applications, the waste water run off is typically contaminated with solids, such as small metal objects, litter and oils or grease and other toxic or hazardous contaminants. Increasing environmental awareness of the effects of disposal of contaminated water into water courses had led to greater demand for collection of such waste water run off from washing facilities, typically in collection vessels or tanks which must be periodically emptied at considerable cost for treatment prior to disposal.

According to the present invention there is provided a waste water treatment apparatus comprising a first water treatment stage for removing solid contamination from the waste water, a second water treatment stage for removing oil and other immiscible low specific gravity contaminants from the waste water, and a third water treatment stage, wherein the waste water is aerated to create optimum conditions for microbial decomposition of contaminants within the waste water.

The waste water may be inoculated with micro-organisms in said third water treatment stage to digest specific contaminants.

At least one further treatment stage may be provided downstream of said third stage comprising at least one further filtration stage and/or a dosing stage wherein the waste water is dosed with an additive, such as chlorine.

In one embodiment the apparatus comprises a housing or tank having a base, a pair of side walls extending upwardly from said base and a pair of end walls extending upwardly from said base to extend transversely between said side walls, and at least one dividing wall extending between said side walls to divide said housing or tank into a plurality of chambers, wherein a respective one of said water treatment stages is accommodated in each of said plurality of chambers, wherein a waste water flow path is defined through said housing or tank such that the waste water passes through said plurality of chamber consecutively from an upstream chamber to a downstream chamber.

In one embodiment the first water treatment stage is accommodated within a further housing mounted on an end wall of said housing or tank, preferably adjacent an upstream end of said tank or housing, said further housing defining a vessel containing a filtration media through which waste water is arranged to pass.

Preferably the vessel is provided with a waste water inlet at or adjacent a lower end thereof and a waste water outlet at or adjacent an upper end thereof such that waste water flows upwardly through the filtration media contained therein. The waste water outlet may communicate with a first chamber of the housing or tank adjacent said further housing. Preferably the waste water outlet comprises a feed pipe extending from said further housing into said first chamber. A strainer plate is provided over an inlet end of said feed pipe and/or an outlet end of said feed pipe may be provided with a filter, such as a mesh sock. Preferably the vessel comprises an inverted conical body. A drain outlet may be provided at a lower end of the vessel, the drain outlet being provided with a valve or closure.

Preferably the second water treatment stage is accommodated within one of the chambers defined within the housing or tank, preferably within said upstream chamber, said second water treatment stage comprising a conduit extending with the chamber between said side walls of the housing or tank located at a height substantially corresponding to the normal level of water within the chamber, said conduit incorporating one or more openings whereby oil or other low specific gravity contaminants floating on waste water drain into said conduit, the conduit communicating with an oil storage reservoir located within the base of the housing or tank.

The second water treatment stage may be accommodated within the first chamber of said housing of tank adjacent said further housing.

Preferably one or more transfer pipes extend between adjacent chambers of said housing or tank, over or through the respective intermediate dividing wall, for transferring waste water between said chamber. Preferably said one or more transfer pipes extend between a lower region of a respective upstream chamber and an upper region of a respective downstream chamber. A filter may be provided on the inlet end and/or outlet end of said one or more transfer pipes.

In one embodiment an inlet end of said one or more transfer pipes is covered by a body of open cell foam defining an inlet filter.

Preferably an outlet filter is provided an outlet end of said one or more transfer pipes. The outlet filter on at least one of said one or more transfer pipes located within said downstream chamber may comprise an activated carbon filter.

Preferably the third water treatment stage is defined by at least one of said one or more transfer pipes, wherein the liquid within at least one transfer pipe is inoculated with micro-organisms. Means may be provided for aerating the water in said at least one transfer pipe.

An embodiment of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which Figure 1 is a part sectional side view of a mobile waste water treatment apparatus in accordance with an embodiment of the present invention; and Figure 2 is a plan view of the water treatment apparatus of Figure 1.

As illustrated in the drawings, a mobile waste water treatment apparatus in accordance with an embodiment of the present invention comprises a housing or tank 2 having a bottom wall 4, a pair of side walls 6,8 and a pair of end walls 10,12, the housing or tank being divided into three chambers or compartments A,B,C by a pair of spaced apart dividing wallsl4,16 extending between the side walls 6,8 intermediate the end walls 10,12, each compartment A,B,C being adapted to further filter and clean waste water passing therethrough to an increasingly high standard as the waste water passes through the housing or tank, as will be described below in more detail.

An upper side of the housing or tank may be closed by doors which may be pivotally mounted at the upper ends of the end walls 10,12, whereby the doors can be closed to close the housing or tank or opened to provide access to the compartments of the chamber and the components located therein.

A pair of tine receiving slots 20,21 are provided in a base portion of the housing or tank 2, below the bottom wall 4, to enable the housing or tank 2 to be moved by a fork lift vehicle. Thus the water treatment apparatus comprises a self contained unit that can be readily transported and located where waste water treatment is required.

A bunded oil storage tank 22 is provided in a lower part of the first compartment A, delimited by an upper wall 23. The oil storage tank 22 is provided for storing oil and other low specific gravity contaminants separated from the waste water, as will be described below in more detail. The oil storage tank 22 is provided with a drain outlet (not shown) in an adjacent end wall 12 of the housing or tank 2. The oil storage tank 22 is bunded (of double wall construction) by virtue of the double walled structure of the base region of the housing or tank to reduce the risk of leakage.

A course filtration unit 24 is mounted on a first end of the housing or tank adjacent the first compartment A of the housing or tank, for initially receiving waste water to be treated. A bed of stones 18 or similar course filtration media is located within the conical body of the course filtration unit 24. An inlet pipe 25 is provided for passing waste water into a lower region of the course filtration unit 24. A drain valve 3 is provided at a lower end of the conical body of the course filtration unit. The course filtration unit 24 communicates with the first compartment A via an opening in the adjacent end wall 12 of the housing or tank at an upper end of the course filtration unit 24, through which opening a feed pipe 26 passes. A strainer plate 27 is provided over or adjacent an inlet end of the feed pipe 26 while a mesh sock 28 is provided on a outlet end of the feed pipe 26 to provide further solids removal.

Waste water is passed into the inlet pipe 25 of the course filtration unit 24 via a water pump 29.

An oil skimming device in the form of an oil separation pipe 30 extends between the side walls 6,8 of the housing or tank in an upper region of the first compartment A. A series of elongate slots or openings are formed in a side of the oil separation pipe having a series of slots or openings therein along the length thereof at the vertical midpoint of the pipe, for draining low specific gravity contaminants into the oil separation pipe from the first compartment. Such low specific gravity contaminants, in particular oils, tend to float on the top of the water located in the first compartment A and therefore can be drained into the oil separation pipe 30 by virtue of its position in an upper region of the first compartment.

As shown in Figure 2, the oil separation pipe 30 communicates with the oil storage tank 22 via a drain hose 32, preferably located within the first compartment for protection and to reduce the risk of leakage to the environment.

Three laterally spaced transfer pipes 34 communicate between the first and second compartments A,B, such transfer pipes 34 extending from a lower region of the first compartment A, passing through the intermediate dividing wall 16 and opening into an upper region of the second compartment B, as shown in the drawings. Blocks of open cell foam filtration material cover lower inlet ends of the transfer pipes in the bottom of the first compartment to act as inlet filters 35 for the transfer pipes 34.

Outlet ends of the transfer pipes 34, located in an upper region of the second compartment B, may be provided with filters or strainers 36, such as mesh socks.

Preferably the water within the transfer pipes 34 and/or the water within the second compartment B may be inoculated with micro-organisms having an affinity for the contaminants to be removed. Where the transfer pipes 34 contain said micro-organisms, the filters 35,36 at the inlet and outlet ends of the transfer pipes may be adapted to prevent passage of the microbes therethrough, preventing loss thereof from the transfer pipes 34. However, the waste water may contain sufficient natural microbes for adequate decomposition of the contaminants within the waste water without requiring the addition of micro-organisms.

The micro-organisms may be selected to feed on the particular contaminants, such as the particular organic compounds or chemical contaminants, to be removed, such that the apparatus can be tailored to suit particular applications.

Further transfer pipes 38 extend between the second and third compartments B,C, passing through the dividing wall 14 therebetween. The inlet ends of the further transfer pipes 38, located in a lower region of the second compartment B, are provided with blocks of open cell foam material acting as inlet filters 39. The outlet ends of the further transfer pipes 38, located in an upper region of the third compartment C, may be provided with activated carbon filters 40 to remove contamination from the water passing into the third compartment C. Activated carbon is a form of carbon processed to incorporate numerous small, low-volume pores that increase the surface area available for adsorption or chemical reactions To aerate the water within the transfer pipes 34, and preferably also the further transfer pipes 38, air diffusers 19 are provided in the lower end of each transfer pipe, said air diffusers 19 communicating with an air pump 40, in order to create optimum conditions for microbial decomposition of contaminants within the waste water. This aeration is particularly important where a microbe habitat is maintained within the transfer pipes.

The water pump 29 is housed in a pump housing 42 mounted on said first end of the housing or tank 2, to one side of the course filtration unit 24. The air pump 40 for aerating the water in the transfer pipes 34 and further transfer pipes 38 is also mounted in the pump housing 42.

A further water treatment unit 44, such as a chlorination unit, may be mounted on a second end of the housing or tank 2, opposite said first end, to provide a final water treatment process, whereby the water may be dosed with the chlorine and/or other water treatment additive.

In use, waste water is pumped into a lower region of the course filtration unit 24 via the water pump 29 and passes upwardly through the course filtration media 18 located therein before passing into the first compartment A through the filter 28 provided on the outlet of the feed pipe 26.

The waste water, having a substantial part of the solid contaminants removed in the course filtration unit 24, passes into the first compartment A, where are oil or other low specific gravity contaminants tend to settle onto the surface of the water. Such contaminants then drain into the oil separation pipe 30 and are drained into the oil storage tank 22.

Water is then passes into the transfer pipes 34, through the foam inlet filters 35.

The aeration of the water in the transfer pipes 34 creates ideal conditions for micro-organisms within the water digest the specific chemical contaminants within the water. Air is passed into the transfer pipes 34 through the air diffusers 19 therein via the air pump 40, aerating the water and creating the required conditions for the good health of the micro-organisms. In the absence of such aeration there is a risk that anaerobic conditions may be created, killing the micro-organisms.

The treated waste water then passes into the upper region of the second compartment B via the outlet ends of the transfer pipes 34 and out of the lower region of the second compartment B into the further transfer pipes 38, via the foam inlet filters 39 thereof.

The water then passes through the activated carbon filters 40 on the outlet ends of the further transfer pipes 38 before passing into the third compartment C. The water in the third compartment C is substantially free of contamination at such point in the process. However, it is envisaged that a further treatment process 44 may be provided downstream of the third compartment C, such as a chlorination process, resulting in an outlet stream of water that is essentially clean and safe for reuse or disposal.

The invention is not limited to the embodiment(s) described herein but can be amended or modified without departing from the scope of the present invention.

Claims

Claims 1. A waste water treatment apparatus comprising a first water treatment stage for removing solid contamination from the waste water, a second water treatment stage for removing oil and other immiscible low specific gravity contaminants from the waste water, and a third water treatment stage, wherein the waste water is aerated to create optimum conditions for microbial decomposition of contaminants within the waste water.
2. An apparatus as claimed in claim 1, comprising at least one further treatment stage downstream of said third stage comprising at least one further filtration stage and/or a dosing stage wherein the waste water is dosed with an additive.
3. An apparatus as claimed in claim 1 or claim 2, comprising a housing or tank having a base, a pair of side walls extending upwardly from said base and a pair of end walls extending upwardly from said base to extend transversely between said side walls, and at least one dividing wall extending between said side walls to divide said housing or tank into a plurality of chambers, wherein a respective one of said water treatment stages is accommodated in each of said plurality of chambers, wherein a waste water flow path is defined through said housing or tank such that the waste water passes through said plurality of chamber consecutively from an upstream chamber to a downstream chamber.
4. An apparatus a claimed in claim 3, wherein said first water treatment stage is accommodated within a further housing mounted on an end wall of said housing or tank, preferably adjacent an upstream end of said tank or housing, said further housing defining a vessel containing a filtration media through which waste water is arranged to pass.
5. An apparatus as claimed in claim 4, wherein said vessel is provided with a waste water inlet at or adjacent a lower end thereof and a waste water outlet at or adjacent an upper end thereof such that waste water flows upwardly through the filtration media contained therein.
6. An apparatus as claimed in claim 5, wherein the waste water outlet communicates with a first chamber of the housing or tank adjacent said further housing.
7. An apparatus as claimed in claim 6, wherein waste water outlet comprises a feed pipe extending from said further housing into said first chamber.
8. An apparatus as claimed in claim 7, wherein a strainer plate is provided over an inlet end of said feed pipe.
9. An apparatus as claimed in claim 7 or claim 8, wherein an outlet end of said feed pipe is provided with a filter, such as a mesh sock.
10. An apparatus as claimed in any of claims 5 to 9, wherein the vessel comprises an inverted conical body.
11. An apparatus as claimed in claim 10, wherein a drain outlet is provided at a lower end of the vessel, said drain outlet being provided with a valve or closure.
12. An apparatus as claimed in any of claims 3 to 11, wherein said second water treatment stage is accommodated within one of said chambers defined within the housing or tank, preferably within said upstream chamber, said second water treatment stage comprising a conduit extending with the chamber between said side walls of the housing or tank located at a height substantially corresponding to the normal level of water within the chamber, said conduit incorporating one or more openings whereby oil or other low specific gravity contaminants floating on waste water drain into said conduit, the conduit communicating with an oil storage reservoir located within the base of the housing or tank.
13. An apparatus as claimed in claim 12, when dependent upon any of claims 6 to 11, wherein said second water treatment stage is accommodated within the first chamber of said housing of tank adjacent said further housing.
14. An apparatus as claimed in any of claims 3 to 13, wherein one or more transfer pipes extend between adjacent chambers of said housing or tank, over or through the respective intermediate dividing wall, for transferring waste water between said chamber.
15. An apparatus as claimed in claim 14, where said one or more transfer pipes extend between a lower region of a respective upstream chamber and an upper region of a respective downstream chamber.
16. An apparatus as claimed in claim 14 or 15, wherein a filter is provided on the inlet end and/or outlet end of said one or more transfer pipes.
17. An apparatus as claimed in claim 16, wherein an inlet end of said one or more transfer pipes is covered by a body of open cell foam defining an inlet filter.
18. An apparatus as claimed in claim 16 or 17, wherein an outlet filter is provided an outlet end of said one or more transfer pipes.
19. An apparatus a claimed in claim 18, wherein said outlet filter on at least one of said one or more transfer pipes located within said downstream chamber comprises an activated carbon filter.
20. An apparatus as claimed in any of claims 14 to 19, wherein said third water treatment stage is defined by at least one of said one or more transfer pipes, wherein the liquid within at least one transfer pipe is inoculated with micro-organisms.
21. An apparatus as claimed in claim 20, wherein means are provided for aerating the water in said at least one transfer pipe.
22. A waste water treatment apparatus substantially as described herein with reference to the accompanying drawings.