Wastewater production and its subsequent treatment is a major problem for every industry and for the society as well. Monitoring the wastewater characteristics is necessary in order to evaluate the performance of treatment processes as well as to permit their discharge into the local water resources. Biochemical oxygen demand (BOD) is one of the most important and frequently used parameters for monitoring water and wastewater which is estimated by determining the amount of oxygen required by aerobic microorganisms degrading organic matters. The BOD value represents the amount of biodegradable organic compounds. The standard method to measure biodegradable organic levels in wastewater is 5-day biochemical oxygen demand assay (BOD5). The conventional BOD test has certain benefits such as being a universal method of measuring most wastewater samples, and furthermore, no expensive equipment is needed. It has, however, the limitations of being time consuming, and consequently it is not a suitable method for on-line process monitoring. The control of wastewater treatment plants is very difficult or even impossible using the dir=ltr Keywords : Cell-based biosensor, wastewater, BOD, activated sludge, flow injection analysis
