Activated sludge wastewater treatment system and method

Abstract

A improved activated sludge system and method for treating wastewater containing contaminants is disclosed which offers a broad array of advantages over conventional activated sludge wastewater treatment systems, including smaller size, higher rates of operation, higher oxygen transfer efficiency, lower operating costs, and a substantially decreased level of excess sludge production. The improved activated sludge waste treatment system of the present invention has two processing tanks rather than the several tanks that are commonly found in activated sludge systems for treatment and sludge management equalizations, including anaerobic processes. The first processing tank is a contact tank which hosts a reaction which functions not merely to digest the maximum amount of contaminants, but instead to bind contaminants to the microorganisms through absorption, adsorption, precipitation, or digestion so that they can then be removed from the liquid in a solid/liquid separator. The activated sludge removed by the solid/liquid separator is then supplied to a digester tank containing a high concentration of activated sludge, where virtually complete digestion is achieved to minimize the volume of solids remaining. Activated sludge is provided from the digester tank to the contact tank to facilitate the reaction in the contact tank.