FOAMING IN ACTIVATED-SLUDGE PLANTS - A SURVEY IN QUEENSLAND, AUSTRALIA AND AN EVALUATION OF SOME CONTROL STRATEGIES

Abstract

Activated sludge sewage treatment plants that were affected by biological foams attributed to the presence of actinomycetes were surveyed in Queensland, Australia. Nocardia amarae and Nocardia pinensis were the predominant organisms found to accumulate selectively in the foam phase. Foaming was shown to be a significant problem in Queensland with 92% of surveyed plants being affected. A total of 60% of these plants suffered from bulking, however, no correlation between these two problems was noted. No operational, design, influent or weather feature was found to be consistent in all foaming plants. Apart from the fact that the plants were all variations of the activated sludge process, the o..