EFFECT OF ALTERNATING AEROBIC AND ANAEROBIC CONDITIONS ON THE ECONOMICS OF THE ACTIVATED-SLUDGE SYSTEM

Results of our trials demonstrate that the alternating aerobic/anaerobic activated sludge (AAA-CMAS) system is capable of producing effluent of high quality in either fully-loaded or under-loaded conditions. The aeration energy saving and the sludge reduction of the AAA-CMAS system was shown to be of the order of 30% and 15% respectively. Because denitrification process is taking place within the reactor under controlled conditions and not in the sedimentation tank where degree of densification cannot be controlled, effluent of the AAA-CMAS system was found to contain much less suspended solids and E. coli counts than that of the conventional system, resulting in further cost saving in chlorination and in backwashing of the filter.