CONTROL OF BACTERIAL FOAMING IN ACTIVATED-SLUDGE PROCESS BY CHLORINATION

Nocardia amarae ST6, isolated from a local sewage treatment plant, was suggested to cause foaming in activated sludge process. Toxicity test s by using pure cultures showed that N. amarae ST6, the foaming bacter ium, was more sensitive to hypochlorite than other non-foaming bacteri a such as Pseudomonas aureginosa ST1 and Escherichia coli ST2. Results of toxicity tests in a laboratory-scale activated sludge unit confirm ed the success of using chlorination to control Nocardia foaming in ac tivated sludge process.