Online BOD Analysis in Waste Water Treatment Plants

The biochemical oxygen demand (BOD) reflects the demand of oxygen that is needed for the degradation of all biological degradable substances in water. Thus, the BOD, also called biological oxygen demand, is an important indicator for the assessment of the pollution of water. Its fast analyses allows the optimal control of a waste water treatment plant (WWTP) with regard to nutrient dosage and/or ventilation strategies.

LAR's BioMonitor is an online BOD analyzer for the determination of the total biochemical oxygen demand. The analyzers' functional principle is similar to a miniature biological WWTP. The waste water to be tested is mixed with activated sludge and air and continuously passed through a multistage measurement cascade. Upon exiting the cascade, the residual oxygen is measured with an oxygen sensor. The analyzer determines the degradation of nitrogen as well as carbon compounds within minutes. This characterizes a huge advantage against the regulated BOD5 measurement, that needs 5 days and measures the carbonaceous-BOD only. Moreover, using the plant's own activated sludge the BioMonitor delivers direct information on the treatment processes and thus, allows the highest applicability on the real process.

Using BioMonitor, operators can control their waste water treatment effectively and thus, realize enormous cost savings regarding blowers and/or nutrient dosage.