ANAEROBIC DIGESTER WASTEWATER TREATMENT

Effluent sludge is anaerobically digested to remove volatile organic material and render it stable and suitable for land spreading. The process can take 12-30 days and the digesters are large. The sludge is kept mixed by gas recirculation or stirring.

An anaerobic digester is a tank or vessel which excludes oxygen and in which a sludge or a liquid effluent is modified by the action of anaerobic bacteria. Organic material in the effluent is converted to methane and carbon dioxide (biogas) and the BOD and COD value of the effluent is reduced. The biogas can be used to heat the effluent to the optimum temperature of 35

ANAEROBIC TREATMENT OF WASTEWATER