Method of and apparatus for monitoring a waste influent stream to a waste treatment biological basin which contains active microorganisms for levels of materials that are toxic or otherwise injurious to the microorganisms in the basin involving the (a) measurement of the rate of oxygen uptake, R, in...http://www.google.ca/patents/US4260490?utm_source=gb-gplus-sharePatent US4260490 - Biomonitor to safeguard water purification process from toxicants
