AU779522B2

AU779522B2 - Waste treatment system

Info

Publication number: AU779522B2
Application number: AU11097/01A
Authority: AU
Inventors: Peter Harte; Sheridan Morley
Original assignee: Bvci Pty Ltd
Current assignee: Bvci Pty Ltd
Priority date: 2000-01-17
Filing date: 2001-01-08
Publication date: 2005-01-27
Anticipated expiration: 2021-01-08
Also published as: AU1109701A

Description

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION STANDARD PATENT Applicant(s): SHERIDAN MORLEY PETER HARTE Invention Title: WASTE TREATMENT SYSTEM The following statement is a full description of this invention, including the best method of performing it known to me/us: 2 WASTE TREATMENT SYSTEM This invention relates to a waste treatment system for treating sewage and other waste material from domestic and industrial environments. The invention is an improvement to that disclosed in our Australian patent number 712789.

Most domestic waste treatment systems simply comprise a convention septic tank in which sewage and other waste material are treated. The septic tank has an outlet for egress of liquid waste material which generally is passed through a long underground pipe to disburse into the surrounding soil. Generally, the liquid which exits the septic tank is not suitable for above-ground use due to the high bacteria and solid content.

Our abovementioned Australian patent discloses an improved waste treatment system which provides output liquid which is suitable for above-ground use.

*The object of the present invention is to provide further improvements to the system disclosed in the above patent.

The invention, in the first aspect, may be said to reside in a waste treatment system including; a primary tank for receiving waste material and for allowing solids and liquid to separate; an aeration tank coupled to the primary tank for receiving and temporarily retaining liquid and suspended solids from the primary tank for aerobic treatment in the aeration tank; a humus tank coupled to the aeration tank for receiving and storing aerobically treated liquid from the aeration tank; a solids removal conduit in the humus tank, the solids removal conduit having an inlet; an air tube coupled to the solids removal conduit \\mebfies\homeS\paulad\Keep\speci\2 waste treatment system -2.doc 8/01/01 -3for providing air to the solids removal conduit so that the air flows upwardly through the solids removal conduit to create suction at the inlet to draw liquid and solids in the humus tank into the solids removal conduit for removal from the humus tank.

The invention provides for removal of solids which may pass from the aeration tank into the humus tank thereby increasing the purity of the liquid in the humus tank and which is outputted from the humus tank.

Preferably the inlet to the solids removal conduit is adjacent a bottom portion of the humus tank and a second solids removal conduit is provided in the humus tank, the S" 15 seconds solids removal conduit having an inlet which is arranged at the intended level of liquid in the humus tank, the second solids removal conduit having a second air tube for providing air to the second solids removal conduit so as to cause suction through the inlet of the seconds solids removal conduit to draw liquids and solids into the second solids removal conduit.

oooo According to this preferred aspect of the invention the first mentioned solids removal conduit provides a sludge removal system for removing sludge which may settle at the bottom of the humus tank and the seconds solids removal conduit is a skimmer for skimming floating solids from the liquid in the humus tank.

Preferably the solids removal conduit and the second solids removal conduit are connected to or integral with a sludge return conduit which extends to the primary tank for returning collected liquids and solids to the primary tank.

Preferably means for delivering air is provided in the aeration tank for causing the liquid and suspended solids in the aeration tank to undergo the aerobic treatment.

H,\Luisa\Keep\Speci\Morley-Harte 11097-01.doc 4/11/04 4 r r Preferably an air pump is provided for supplying air to the means for delivering air and also to the air tube connected to the solids removal conduit and the air tube connected to the second solids removal conduit.

A preferred embodiment of the invention will be described, by way of example, with reference to the accompanying drawings in which; Figure 1 is a cross-sectional view of a system embodying the invention; Figure 2 is a plan view of the system of Figure 1; and Figure 3 is a view along the line III to III of Figure 1.

Figure 1 shows a treatment system 10 is which comprises a conventional sewage tank 12 which has a sewer inlet 14 for receiving sewage and other waste material from a house (not shown). The sewage tank 12 have access lids 16 as is conventional and has primary and secondary chambers 12a and 12b separated by a partition 18. A discharge tube 20 is THE NEXT PAGE IS PAGE 7 Hi\Luisa\Keep\Speci\Morley-Harte 11097-01.doc 4/11/04 7 provided for discharge of liquid waste material which would conventionally include a large proportion of solid matter.

The sewage tank 12, as is conventional, allows for conventional solids separation to occur and the discharge outlet 20 would normally be connected to an underground pipe system for receiving the overflow from the sewage tank 12 and for enabling dispersion of the overflow of liquid into the ground. However, according to this embodiment of the invention, the discharge tube 20 is coupled to a further treatment tank 30 which includes an aeration compartment 32 and a humus compartment 34 which are separated by a baffle or wall 36. The discharge tube has an outlet end 21 which is arranged above a medium 38, such as a BIO BLOCK (trade mark), in the aeration compartment 32 which acts to increase the surface area of the aeration compartment 32. The medium 38 simply is a member which enables bacteria to grow and therefore increases the surface area within the compartment 32. The 20 medium 38 may take the form of a grid, lattice work or other network simply presenting surface area upon which bacteria can accumulate and grow within the compartment 32.

S"Alternatively, rather than provide the medium 38 directly S"below the outlet end 21 the medium 38 could be provided on 25 side walls of the aeration tank 32 as shown by reference i 38' in Figures 1 and 2. The tank 30 may have access lids An air pump 42 is arranged within the tank 30 and is powered from a power source (not shown) such as a conventional 240 volt electric supply. The pump 42 is connected to a air discharge ring 44 via a conduit 46 for delivery of air into the aeration compartment 32. The waste material in the aeration compartment 32 undergoes aerobic biological treatment. Typically, in domestic environment, a relatively long aeration detention occurs in the compartment 32 of usually twenty-four hours or more \\melbfiles\home\paulad\Keep\speci\2 waste treatment system -2.doc 8/01101 8 thereby providing a high degree of BOD removal of approximately 95% to 98%. Micro-organisms exit in the endogenous phase of respiration by maintaining a low BOD loading, a high mixed-liquor suspended solids, and long retention time within the compartment 32.

A filtration unit 50 is provided in the humus tank which can be connected to wall 36 by a support bracket 56. The tube 54 may have a diameter of 30 to 40 cm. The tube 54 has a bio-reactor 52 arranged within it which comprises the same medium as the medium 38 or 38' previously described.

That medium increases the surface area within the tube 54 and enables bacteria to grow on the increase surface area which can react with solids in the liquid within the aeration tank 32 to affectively separate the solids from the liquid by bio-reaction thus purifying the liquid which passes up through the tube 54.

It should be noted that the top end of the tube 54 is arranged above liquid level in the aeration tank 32 so that liquid entering the tube 54 must enter from the bottom of the tube. Both the top and the bottom of the tube can be left completely open. The tube 54 has an outlet tube 58 communicating with it so that liquid in the tube 54 can pass out of the tube 54 through the tube 58. The tube 58 extends through the wall 36 and joins a vertically extending tube 60 which has an outlet end 62 arranged at the bottom of the humus tank 34.

The cross-sectional area of the outlet tube 58 and also the tube 60 is less than the cross-sectional area of the inlet and also outlet 80 from the humus tank. The smaller diameter outlet tube 58 together with the filtration unit formed by the tube 54 and the medium 52 forms a flow reduction for liquid passing through the system to slow down the flow of water and allow the medium 52 to create bio-reaction with solids in the liquid passing up through \\melb_files\homeS\paulad\Keep\speci\2 waste treatment system -2.doc 8/01/01 9 the tube 54. Furthermore, the slow down of the flow of liquid also enables any heavy particles to drop to the bottom of the aeration tank 32. Air emanating from the air discharge ring 44 will tend to cause an upward lift from the base of the aeration chamber 32 thereby drawing any settled solids upwardly in the aeration tank 32 for further aerobic treatment within the aeration compartment 32.

The tube 60 in the humus tank 34 tends to deposit any solids which do pass through the filter 50 and out through the outlet 58 on the bottom of the humus tank 34. Since suspended solids which do pass through the outlet 58 are primarily deposited on the bottom of the humus tank 34 the purity of liquid in the humus tank 34 is improved notwithstanding the fact that some small amount of suspended solids may pass through the outlet 58 and tube A first solids removal conduit 75 and a second solids removal conduit 76 are arranged within the humus tank 34.

Conduits 75 and 76 are best shown in Figure 3. The conduit is generally a vertically extending tube which has an inlet end 109 arranged adjacent the bottom of the humus tank 34. An air tube 92 extends from the pump 42 to the conduit 75 and joins the conduit 75 just upwardly from the inlet end 109. When air is blown into the tube 92 from the pump 42 the air enters the conduit 75 and bubbles up through liquid in the conduit 75. The upward flow of air within the conduit 75 creates suction at the inlet end 109 which tends to suck liquid and any sludge, which has accumulated on the bottom of the humus tank 34 by a deposit of solids which may pass through the outlet 58 and tube up through the tube 75. The tube 75 is connected to a sludge return conduit 78 which, as is best shown in Figure 1, returns to the primary tank 12 so that the sludge can be deposited in the primary tank 12 for treatment and \\melb files\homeS\paulad\Keep\speci\2 waste treatment system -2.doc 8/01/01 10 circulation through the system as previously described.

The conduit 76 has a section 105 and an upwardly extending section 107 which extends upwardly from the lower end of the section 105. An inlet 110 is provided at the upper end of the section 107 and is generally at the level L of liquid within the humus tank 34. An air tube 94 which extends from the pump 42 is coupled to the section 105 towards the lower end of the section 105. Once again, air which is delivered into the section 105 from the tube 94 flows upwardly through the tube 105 creating a suction through the tube 107 and therefore through inlet 110 so that solids which may float on the liquid L can be skimmed off the liquid L through the inlet 110 by the suction created in the section 107 and again returned to the primary tank 12 through a conduit 78' which extends parallel with the conduit 78.

The conduits 78 and 78' may be integral with the tubes and 105 or may be connected by a snap hose fitting or the like. Furthermore, rather than providing separate conduits 78 and 78' a single conduit 78 can be provided which has two branches at one end for connection to the conduits and 105.

Thus, the inlet 109 acts to draw sludge which accumulates on the bottom of the humus tank 34 and the inlet 110 acts as a skimmer to skim floating solids from the top of the liquid level L in the humus tank 34. Thus, any solids which do pass to the humus tank 34 can be recirculated back to the primary tank 12 for continued processing.

The conduits 75 and 76 can be supported within the humus tank by suitable brackets (not shown).

A further medium 77 which is similar to the medium 38 previously described may be provided in the humus tank 34 adjacent inlet end to the outlet pipe 80. The discharge \\melbfiles\home$\paulad\Keep\speci\2 waste treatment system -2.doc 8/01/01 11 pipe 80 leads to a contact tank 95 which may be included if additional treatment of the liquid phase delivered from the tank 34 is required. For example, the tank 95 may include a chlorination dispenser 97 and provide chlorine treatment of the liquid phase if the liquid phase is to be used above ground and sprayed as distinct from drip deposited onto the ground. A pump 102 may be included within the tank 95 for pumping the liquid out of an outlet 101. The outlet 101 may be connected to the spray system (not shown) for spraying the liquid phase or to drip irrigation piping (not shown) for drip depositing the liquid phase onto the ground. A high water level alarm 103 may be included for providing an alarm if the liquid level in the tank exceeds a desired level.

The outlet opening 101 in Figure 1 is arranged below the level of the partition wall 36 so that the liquid level in the compartment 32 cannot rise above the partition wall 36 to deposit unfiltered treated waste from the compartment 32 into the compartment 34 which would then discharge via the outlet 101. Once the system is fully operational, the liquid level in the septic tank 10, aeration compartment 32, and humus tank 34 is approximately at the level of the tray 54 so that as liquid enters the sewage inlet 14, a corresponding amount of liquid is caused to flow through the tubes 52 into the tray 54 and out through the outlet tube 58 into the humus tank 34 thereby causing liquid in the humus tank 34 to flow through the discharge pipe into the contact tank 95 and so the corresponding amount of liquid can exit the outlet 101.

The discharge pipe 80 may be connected to a vertical discharge section 81 within the tank 95 for delivery of liquid towards the bottom of the tank Thus, once treated and relatively clear effluent liquid passes through the humus tank 32, it can be further treated \\melb_files\home$\paulad\Keep\speci\2 waste treatment system -2.doc 8/01/01 12 in the contact tank 95 before being used above ground on a garden or the like.

Since modifications within the spirit and scope of the invention may readily be effected by persons skilled within the art, it is to be understood that this invention is not limited to the particular embodiment described by way of example hereinabove.

*0 \\melb_files\home$\paulad\Keep\speci\2 waste treatment system -2.doc 8/01/01

Claims

2. The system of claim 1 wherein the inlet to the solids removal conduit is adjacent a bottom portion of the humus tank and a second solids removal conduit is provided 25 in the humus tank, the seconds solids removal conduit having an inlet which is arranged at the intended level of liquid in the humus tank, the second solids removal conduit having a second air tube for providing air to the second solids removal conduit so as to cause suction through the inlet of the seconds solids removal conduit to draw liquids and solids into the second solids removal conduit.
3. The system of claim 1 or claim 2 wherein the solids removal conduit and the second solids removal conduit are connected to or integral with a sludge return conduit which extends to the primary tank for returning collected liquids and solids to the primary tank. \\melbfiles\home$\paulad\Kep\speci\2 waste treatment system -2.doc 8/01/01 14
4. The system of any one of claims 1 to 3 wherein means for delivering air is provided in the aeration tank for causing the liquid and suspended solids in the aeration tank to undergo the aerobic treatment. The system of claim 4 wherein an air pump is provided for supplying air to the means for delivering air and also to the air tube connected to the solids removal conduit and the air tube connected to the second solids removal conduit.
6. A waste treatment system substantially as hereinbefore described with reference to the accompanying S 15 drawings. Dated this 4th day of November 2004 SHERIDAN MORLEY and PETER HARTE By their Patent Attorneys GRIFFITH HACK Fellows Institute of Patent and STrade Mark Attorneys of Australia H-\Luisa\xeep\speci\Morley-Harte 11097-O1.doc 4/11/04