Project

The plant is designed to treat up to 400m³/day of landfill leachate from cells of varying maturities, to reduce the COD, ammonia and nitrate concentration prior to sewer discharge.

Responsibilities

Whitewater was retained by the Principal Contractor to provide process design, equipment specification, oxygen transfer testing and performance trial review.

The plant consists of an influent leachate holding tank, transfer pumps, two 1500m³ SBRs and an effluent holding tank all constructed in reinforced concrete. The SBRs are covered to retain heat.

Denitrification takes place during anoxic filling and methanol dosing is provided to supplement the leachate COD as required. The anoxic stage is followed by aeration using fine bubble diffusers with automatic control of the air blowers by dissolved oxygen concentration. Automatic pH control is provided by caustic soda dosing.

A fully automatic sequence controller allows the operator to set the number of anoxic fill and aeration stages before settlement of the sludge and decanting under gravity into the effluent holding tank. The treated effluent is held until a full analysis has been carried out to ensure compliance prior to discharging to sewer or road tanker.