The Leachate Treatment and Crystalliser Plant treats approximately 4.5 m3/hr of leachate from the various dams at Enviroserv Waste Management’s Holfontein site in Gauteng, South Africa. The leachate is processed in a number of stages with all utilities such as steam, compressed air, caustic soda, drinking and process water provided by the utilities section of the plant. The plant is controlled from a dedicated control room and MCC.
The first processing stage removes any large solids in the leachate solution using an inline filter. The pH is then adjusted before being fed to the crystalliser. The evaporative crystalliser is a single effect, steam driven, forced circulation, vacuum crystalliser and produces slurry and condensate streams. The slurry is concentrated in a settler before being disposed of at the waste site. The condensate undergoes further treatment to remove organics via a biological processing stage. The bio-sludge is then treated with a flocculent and filtered to remove the remaining solid particles. The filter cake is periodically removed and disposed of in the appropriate manner. The filtrate is returned to the client as process water.