AU723747B3

AU723747B3 - Multi-chamber apparatus for treatment of waste water

Info

Publication number: AU723747B3
Application number: AU60632/99A
Authority: AU
Inventors: Peter Boyd
Original assignee: Individual
Current assignee: Individual
Priority date: 1999-11-25
Filing date: 1999-11-25
Publication date: 2000-09-07
Anticipated expiration: 2005-11-25

Description

P/00/011 Regulation 3.2 COMMONWEALTH OF AUSTRALIA Patents Act 1990 COMPLETE SPECIFICATION FOR A PETTY PATENT Name of Applicant: Actual Inventor(s): Address for Service: Invention Title: PETER BOYD PETER BOYD

AHEARNS

Patent Trade Mark Attorneys, GPO Box 1149 Brisbane, Queensland, 4001 MULTI-CHAMBER APPARATUS FOR TREATMENT OF WASTE WATER The following statement is a full description of this invention, including the best method of performing it known to us: -1- MULTI-CHAMBER APPARATUS FOR TREATMENT OF WASTE WATER THIS INVENTION relates to multi-chamber apparatus for treatment of waste water.

The invention has particular application to household sewage treatment plants ("HSTP's") and for illustrative purposes reference will be made to such application. It will be appreciated however that the invention may have application to small commercial and industrial waste water treatment plants.

It is to be understood that the term "water" as is used in this specification refers to water as a carrier and containing other materials such as dissolved and/or suspended solids.

The inventor has installed for many years a multi-chamber waste water treatment plant in domestic and small commercial waste water treatment plants in which raw sewage is received into a first tank and treated anaerobically in a similar manner to the traditional septic tank. Liquid effluent from the first tank is decanted into a second tank. The liquid in the second tank is aerated typically by recirculating the liquid through a venturi which entrains atmospheric air into the liquid stream. Liquid effluent from the second tank is directed to a third tank and chlorinated prior to discharge.

Until recently, the discharge of the chlorinated effluent has been either to spray irrigation or to ground infiltration absorption pits. Unfortunately, the spray irrigation option is increasingly being disallowed by local health authorities because of public health concerns, but the alternatives are not as attractive from a cost point of view and also results in a loss of water which could be used on plants. Also, spray irrigation -2is usually more attractive because it provides more even distribution of irrigating waters and/or is less likely to adversely affect the sodicity of the soil.

Accordingly, it is an object of the present invention to provide multi-chamber apparatus for treatment of waste water which will permit the effluent to be discharged by spray irrigation. Other objects and advantages of the invention may hereinafter become apparent.

The inventor has discovered that, surprisingly, the chlorinated effluent from the third tank may be "polished" sufficiently for discharge by a spray irrigation if passed through backwashable filtration means, particularly a sand filter, of the type often specified for swimming pool filtration systems.

Thus, the invention in one aspect resides broadly in multichamber apparatus for treatment of waste water including: a septic treatment chamber having a wastewater inlet for receiving wastewater and a septic water outlet; an aerobic treatment chamber having a septic water inlet in fluid communication with the septic water outlet, an aerated water outlet, and aeration means for aerating liquid in the aerobic treatment chamber; a chlorination chamber having an aerated water inlet :influid communication with the aerobic water outlet, a chlorinated water outlet, and chlorination means for chlorinating liquid in the chlorination chamber, and backwashable filtration means operatively associated with Ce chlorinated water outlet, the filtration means having a 1e chlorinated water outlet, the filtration means having a -3discharge outlet for discharging filtered water and a backwash outlet in fluid communication with the aerobic treatment chamber, and a sand filter of the type normally specified for filtration of swimming pool water.

The chambers may be provided by separate tanks or vessels, or by a combination of tanks and multi-chamber vessels, or a single vessel with internal walls separating the required chambers from one another. Preferably, the filtration means comprises a pump and a sand filter, the sand filter having piping connections, controls and valving for various operational modes including normal filtration and backwashing. It has been surprisingly found that swimming pool sand filters are of sufficient capacity and effectiveness to produce a filtrate suitable for discharge by spray irrigation, removing substantially pathogens and indicator organisms from the filtrate at least to the extent required for such discharge.

The wastewater may be sewage (hereinafter referred to as black water) receivable from a domestic wastewater reticulation system operatively connected to one or more water closet type toilets. Water receivable from other household drains (such water being referred to hereinafter as grey water) may also be added to the black water stream, or the apparatus of invention may be used to treat the grey water only.

In another aspect, this invention resides broadly in a method of treating waste water including the steps of: passing the waste water into a septic treatment chamber of a capacity sufficient for septic treatment of the wastewater to Droduce septic water; -4decanting the septic water from the septic treatment chamber to an aerobic treatment chamber; aerating the septic water received into the aerobic treatment chamber to produce an aerated water; periodically delivering aerated water from the aerobic treatment chamber to a chlorination chamber for chlorination of the aerated water to produce chlorinated water; periodically filtering the chlorinated water from the chlorination chamber through a sand filter to produce filtered water for discharge, and periodically backwashing the sand filter with clean water, directing the water from the backwashing to the aerobic treatment chamber.

Preferably the aerated water is periodically pumped from the aerobic treatment chamber by using valves to redirect flow from an aeration pump which is normally used to aerate the septic water, recirculating the water being aerated back to, or within, the aerobic treatment chamber.

In order that the invention may be more readily understood and put into practical effect, reference will now be made to the accompanying drawing which illustrates a preferred embodiment of the invention, being a diagrammatic representation of a multichamber apparatus for treatment of waste water.

Referring to the drawing, the multi-chamber apparatus includes a septic treatment chamber 12, an aerobic treatment chamber 14, a chlorination chamber 16 and a backwashable filter The septic treatment chamber receives wastewater through a wastewater line 21. A septic water line 23 provides a fluid connection between the septic treatment chamber and the aerobic treatment chamber. The aerobic treatment chamber and the chlorination chamber are in fluid connection by way of an aerated water line 25. The chlorination chamber has a submersible pump 17 with a chlorinated water outlet 27 connecting the pump to the filter which in turn has a discharge line 29 for discharging filtered water and a backwash line 28 providing fluid communication between the feed side of the filter and the aerobic treatment chamber.

Wastewater is delivered to the septic chamber through the wastewater line, filling the septic chamber 12 to an operating level for anaerobic ("septic") treatment. According to the size of the septic tank and the volumetric flow rate, the wastewater therein has a residence time in which septic treatment takes place according to well known waste treatment principles. The water treated in the septic treatment chamber is decanted by gravity flow through the septic water line 23 to the aerobic chamber 14 in which aeration is effected by recirculating the water through a pump having a venturi in operative connection with the pump outlet, the venturi introducing atmospheric air into the water. The pump recirculates the aerated water back to the aerobic chamber. Water from the aerobic chamber is periodically pumped by the pump to the chlorination chamber 16 through the aerated water line 25, and chlorine is dosed into the water at a level suitable for disinfection. Chlorination also turns some dissolved material into solid material which may still contain undesirable biological entities. The water from the chlorination chamber is periodically discharged through the -6chlorinated water outlet to pass through the filter 20 and out from system through the discharge line 29. The quality of the filtrate passing from the filter through the discharge line has been found to be acceptable for spray irrigation. Periodically, the filter is backwashed with fresh water such as from a domestic water supply, the backwashing liquid being directed through the backwash line 28 to the aerobic treatment chamber 14.

It will be appreciated that while the above has been given by way of illustrative example of the invention, all such modifications and variations thereto as would be apparent to persons skilled in the art are deemed to fall within the broad scope and ambit of the invention as claimed in the following claims.

Claims

1. Multi-chamber apparatus for treatment of waste water including: a septic treatment chamber having a wastewater inlet for receiving wastewater and a septic water outlet; an aerobic treatment chamber having a septic water inlet in fluid communication with the septic water outlet, an aerated water outlet, and aeration means for aerating liquid in the aerobic treatment chamber; a chlorination chamber having an aerated water inlet in fluid communication with the aerobic water outlet, a chlorinated water outlet, and chlorination means for chlorinating liquid in the chlorination chamber, and backwashable filtration means operativelyassociated with the chlorinated water outlet, the filtration means having a discharge outlet for discharging filtered water and a backwash outlet in fluid communication with the aerobic treatment chamber, and a sand filter of the type normally specified for filtration of swimming pool water.

2. Multi-chamber apparatus for treatment of waste water, wherein said sand filter includes piping connections, controls and valving for various operational modes including normal filtration and backwashing.

3. Multi-chamber apparatus for treatment of waste water according to Claim 1 or Claim 2, and wherein said apparatus is as substantially hereinbefore described with reference to the accompanying drawing. Dated this 7 th day of July, 2000 PETER BOYD by his Patent Attorneys AHEARNS I"

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