GB2229434A

GB2229434A - Waste water treatment

Info

Publication number: GB2229434A
Application number: GB9004089A
Authority: GB
Inventors: Bailey John Wright
Original assignee: Individual
Current assignee: Individual
Priority date: 1989-02-23
Filing date: 1990-02-23
Publication date: 1990-09-26
Anticipated expiration: 2010-02-23
Also published as: GB8904191D0; GB9004089D0; GB2229434B

Abstract

Waste fluid e.g. sewage is treated by passing it through one or more brush-like elements 4 each of which waste fluid passes. The fibres support and encourage the growth of bacteria therein which effects bacterial decomposition of the waste material. <IMAGE>

Description

WATER TREATMENT This invention relates to the treatment of fluids, particularly to the treatment of waste fluids to remove waste from the fluid. The invention has particular application to the treatment of sewage.

It is known to treat sewage in a sewage treatment plant by delivering it to first treatment station in which solids are ground and then discharged into another treatment chamber where they are subjected to bacterial action which decomposes the waste material. In this further treatment chamber, air is circulated through the sewage to promote bacterial decomposition. The treated water is thereafter fed to a settling chamber where the solids settle to the bottom and form a sludge. Water from the settling chamber can be passed through a filter and disposed of appropriately.

The present invention is concerned with a method and apparatus which can be used in the further treatment chamber and which enhances the bacterial action for decomposing the waste material.

According to one aspect of the present invention there is provided apparatus for use in waste fluid treatment, the apparatus comprising a plurality of brush-like elements, each of which includes a plurality of fibres through which the waste material is arranged to pass in use, said fibres being arranged to support the growth of bacteria thereon which can subsequently operate to effect bacterial decomposition of the waste material. Preferably each brush-like element comprises a central shaft or tube-like member which carries plurality of radially extending fibres. The fibres can be arranged helically around the shaft or tube-like member. The fibres may be made from a suitable polymer such as an extruded crimped polypropylene with a metallic core. The metallic core may be stainless steel or aluminium. Typically the fibres will be of .5 to 2 mm in diameter.

The brush-like element may be supported upon a frame which includes oppositely located triangular portions for carrying opposite ends of the brush-like elements.

Another aspect of the present invention provides a brush-like element for use in the apparatus defined above, each brush-like element comprising a shaft-like member carrying a plurality of radially extending fibres. The shaft may be a rod or a hollow tube. The fibres may be arranged helically around the shaft.

According to a further aspect of the present invention there is provided a method of treating waste fluid which comprises passing the waste fluid through an apparatus according to said one aspect defined above in order to promote the decomposition of the waste material by the action of bacteria on said fibres.

The present technique has particular application to the treatment of raw sewage, but is not limited to that application.

The invention will be described now by way of example only, with particular reference to the accompanying drawings. In the drawings: Figure 1 is a schematic view of a typical sewage treatment plant for the treatment of water carrying sewage, Figure 2 shows brush-like members which are used in apparatus in accordance with the present invention, Figure 3 is an enlarged view of part of a brush-like member used in the present invention; Figure 4 shows an alternative form of apparatus in accordance with the present invention; and Figures 5 and 5a show an alternative form of brush-like member.

Referring to Figure 1, a typical sewage treatment plant comprises an initial treatment tank into which raw sewage is fed. The initial treatment may include action to pulverise any solids carried in the raw sewage into relatively small particles. By reducing the waste solids to particles of smaller size the resultant surface area of the waste to be acted upon by bacteria in the subsequent treatment is maximised and this helps to promote the bacterial decomposition of the sewage.

The treated sewage is then fed into a second stage, generally marked by the reference numeral 2.

This comprises a series of channels through which the sewage is fed. As it passes through this channel the sewage is aerated to promote the bacterial decomposition of the waste material. After treatment within the stage 2, the treated sewage is then passed into a chamber, not shown, where solids settle to the bottom and form a sludge. Water from the settling chamber can be discharged appropriately. The present arrangement proposes an apparatus for use in the channels of stage 2. Referring to Figure 2 it comprises a frame work, shown generally at 3, which is made up of tubular members and extends longitudinally along the channel. The frame work comprises a base section 5 which carries oppositely disposed inverted V-shaped sections 6.Only one complete pair of Inverted V-shaped sections is shown in Figure 2, but it will be appreciated that a number of these are provided along the length of a channel. Each inverted V-shaped section 6 in conjunction with the base defines a triangular support for a plurality of brush-like members shown generally by the reference numeral 4. Referring to Figure 2 and also Figure 3, each brush-like element comprises a hollow shaft 7 which carries a plurality of radially outwardly extending fibres 8. As shown in Figure 3 the fibres are arranged so that they extend in a helical pattern along the axis of the shaft 7. The fibres are so mounted that the pitch of the helix formed thereby can be varied. Each fibre may be formed from extruded crimped polypropylene which has a core of stainless steel or aluminium. Typically diameter for the fibre is in the range 0.5 mm to 2 mm.

The frame work which supports the brush elements can be made from PVC pressure pipe and the various sections of the frame work may be connected by heat fusion welded joints which are double butted.

In use the frame work is located longitudinally along each channel of the treatment stage 2 of Figure 1 and a plurality of brush-like members 4 are mounted on the frame work as illustrated in Figure 2 of the drawings. It will be appreciated that the tips of the fibres of one element 4 are touching or in close proximity to the tips of the fibres of an adjacent element. In operation the sewage from the treatment stage 1 is then passed into the channel 2 so that it has to pass between the fibres 6 on the brushes. The brush-like members 4 operate to promote the growth of bacteria on the surface of each fibre. This can occur naturally from the bacteria which occur within the waste or by the use of specially bred commercial bacteria fed into the channel.As the sewage passes through the channel it undergoes decomposition by the bacteria which consumes the waste by aerobic digestion. The aerobic digestion can be promoted by the introduction of air or oxygen into the channel by conventional means. As a result of the treatment the water which leaves the exit end of the channel carries decomposed waste which then separates from the water in the settling chamber previously referred to.

Figure 4 shows an alternative configuration of the brush-like elements which can be used in a sewage treatment module. In this arrangement the brush-like elements are mounted with their axes along the longitudinal direction of the sewage treatment module. However it will be appreciated that the way in which the brush-like elements operate to enhance decomposition of the waste material is substantially the same as that described above for the embodiments of Figures 2 and 3.

Figures 5 and 5a show an alternative form of brush-like element 24. This comprises a central shaft 25 carrying a series of angularly spaced lines 26 of radially extending fibres. The shaft 25 is carried by a bracket 28 fixed to a wall 30. The fibres can have a construction similar to that referred to above. The lines 26 of fibres form a paddle like arrangement with the shaft 25. The shaft can be rotated by means of motor operating through a reduction box. The shaft can also be rotated manually by means of handle 32.

It will be appreciated that the apparatus and technique has general application to the purification of liquids, typically water, and that it is not restricted to use in the treatment of sewage.

Claims

CLAIMS:

1. Apparatus for use in waste fluid treatment, the apparatus comprising a plurality of brush-like elements, each of which includes a plurality of fibres through which the waste material is arranged to pass in use, said fibres being arranged to support the growth of bacteria thereon which can subsequently operate to effect bacterial decomposition of the waste material.

2. Apparatus according to claim 1, wherein each brush-like element comprises a central shaft or tube-like member which carries a plurality of radially extending fibres.

2. Apparatus according to claim 2, wherein the fibres are arranged helically around the shaft or tube-like member.

4. Apparatus according to any preceding claim, wherein the fibres are made from a suitable polymer such as an extruded crimped polypropylene with a metallic core.

5. Apparatus according to claim 4, wherein the metallic core is stainless steel or aluminium.

6. Apparatus according to any preceding claim, wherein the fibres are of 0.5 to 2 mm in diameter.

7. Apparatus according to any preceding claim, wherein the brush-like elements are supported upon a frame which includes oppositely located triangular portions for carrying opposite ends of the brush-like elements.

8. A brush-like element for use in the apparatus claimed in any preceding claim, each brush-like element comprising a shaft-like member carrying a plurality of radially extending fibres.

9. A brush-like element according to claim 8, wherein the shaft is a rod or a hollow tube.

10. A brush-like element according to claim 8 or claim 9, wherein the fibres are arranged helically around the shaft.

11. A method of treating waste fluid which comprises passing the waste fluid through an apparatus according to any one of claims 1 to 7 in order to promote the decomposition of the waste material by the action of bacteria on said fibres.

12. Apparatus for use in waste fluid treatment substantially as hereinbefore described with reference to and as shown in the accompanying drawings.

13. A brush-like element substantially as hereinbefore described with reference to and as shown in the accompanying drawings.

14. A method of treating waste fluid substantially as hereinbefore described.