Winterton Leachate Site, Winterton

Raw leachate, collected from the landfill will be pumped to the RLBL. The control of the leachate collection system is existing.

Background

During 2004, The Waste Recycle Group will install a leachate treatment facility with a specifically designed plant incorporating an Aerated Suspended Growth Plant (ASGP) with an additional dissolved air flotation (DAF) plant for assistance in the removal of residual suspended solids and colloidal material in conjunction with chemical dosing for nutrient and pH control at:

The main treatment process is described as follows:

Raw leachate, collected from the landfill will be pumped to the RLBL. The control of the leachate collection system is existing.

From the RLBL, the leachate will be pumped under controlled conditions to the annulus of the ASGP. This zone of the ASGP comprises an aqueous matrix of leachate and biomass and will be aerated continuously for 24 hours per day, 7 days per week. At intervals of 6 hours, mixed liquor will be drawn off into the inner settling zone of the ASGP, where it will be allowed to settle. At pre- determined intervals, a pre-set volume of supernatant will be decanted from the settlement zone into the TLBT. The remaining volume of supernatant and the settled biomass will then be mixed together and pumped back into the aerated zone of the ASGP.

From the TLBT, the treated leachate will be pumped to the header tank of the DAF plant. The DAF plant, using compressed air, coagulant and flocculant aids, will remove solids from the treated leachate, after which the treated leachate will be pumped to the TLBL. From the TLBL the treated leachate will be pumped to sewer. The final discharge pumping system in the TLBL exists and the control of its operation shall be integrated into the leachate treatment plant control system.

During the treatment process, chemical reagents; sodium hydroxide and phosphoric acid, will be added to the aerated section of the ASGP. This will be for pH balancing and nutrient addition respectively.

Equipment Installed

The key elements of the MEICA system are shown on the Process Flow Diagram Drawing No 404 and can be summarised as follows: –