Monitoring pracy komunalnej oczyszczalni ścieków z wykorzystaniem zestawu Microtox

The paper presents the results of acute toxicity investigation of sewage and sewage sludge samples from the municipal treatment plant located in Bialystok. The toxicity was measured by means of the acute test using luminescent bacteria Vibrio fischeri and by Microtox Model 500 analyzer. According to Sawicki’s classification, three out of five raw sewage samples were of high toxicity, contrary to the treated wastewaters in which no toxicity was observed. The obtained results confirmed the correct work of the plant. Treated sewage did not contain toxic chemicals and was safety for the environment. It was also found that regardless of the assessment system, sewage sludge was characterized by high or very high toxicity. Its use may cause a significant threat to the environment.