Improved Sewage Treatment with Ozonated Activated Sludge

A ctivated SLUDGE SEWAGE treatment processes are often inadequate to comply with effluent criteria as promulgated in anti-pollution legislation. Ozonation was studied as a means of improving nutrient removal activated sludge processes without the salinity and other disadvantages of the often used polyvalent metal salt addition. Direct ozonation into the aeration basin of a 150 I/d Phoredox (modified Bardenpho) system led to improved removal of organic substances. Nitrification was improved while phosphate removal was not adversely affected. Beneficial biological activity in the activated sludge was enhanced. The trihalomethane formation potential was reduced. Pollutional loads could be lessened, while an effluent with increased reuse potential was produced.