RAPID BOD MEASUREMENT TECHNOLOGY TO PREVENT INDUSTRIAL WASTE IMPACT ON MUNICIPAL WASTEWATER PLANTS

This paper presents the test results of various rapid biochemical oxygen demand (BOD) instruments to establish online respirometry for process control at wastewater treatment plants during events of industrial waste discharges. Several methods to measure soluble BOD through bacterial respiration (biosensors, and biomembranes reactors) have been implemented by various instrument manufacturers in USA, Germany, and Japan. Respirometry can provide insight into the industrial waste discharge concentration in the plant's influent by the health of the bacteria culture.BOD is generally considered by plant operators to be the most important measure of wastewater strength, but the standard laboratory procedure to measure it, the BOD5 test (Standard Methods, 1992), is far too slow to use for process control. Faster tests for related parameters have been available for years, such as, the chemical oxygen demand (COD) test which takes 2–3 hours, and total organic carbon (TOC) which only measures the content of organic compounds, not other substances that contribute to BOD.The diurnal patterns of BOD loadings and new effluent regulations for wastewater effluent make it desirable to monitor BOD influent concentration in real-time to allow plant operators to respond quickly to BOD fluctuations caused by industrial waste discharge in ways that will prevent process upsets.We tested various presently available respirometric systems and concluded that systems employing bio-reactors using plant inflow provide the most representative behavior of plant's BOD influent changes within minutes. The quick response of these instruments will help to identify high loading of BOD (shock loadings) as it occurs to prevent any violation to the plant's permit. The BIOX-1010 performance in the field including its moderate maintenance make it ideal for application to detect shock loadings for process control.