The settling of sludge is one of the most crucial parameter in the operation of wastewater treatment plants (WWTP). Not only is the whole purification process affected by sludge settling both prior and after the biological treatment step but also the quality of the final effluent, the operation of further treatment units and the whole line of sludge handling. Especially, controlling sedimentation characteristics of the sludge in the post-sedimentation can be named as one of the most important parameters for WWTP operation. Here accurate measurements of sludge levels can be utilised for effective and optimal treatment control. This report provides an evaluation of an optical sludge blanket meter. This includes its performance in measuring and control of sludge levels in WWTP and the potential for better treatment control. The Cerlic CBX has been tested in both laboratory and pilot-scale and at a WWTP. The conclusion is that it can provide automatic and reliable measurements of the sludge blanket. The Cerlic CBX can be used as supplied but it also provides extensive configuration options for demanding applications. The ability to measure actual suspended solid concentrations at various depths reduces the need for compensations or interpretation as necessary when using indirect measurements. The application of the optical sludge blanket meter should therefore facilitate a better control of WWTP operation and buffer variations in incoming sewage flows and loads. It can further provide a continuous process monitoring and thus increase the robustness and reliability of the treatment process. The control of the sludge content in the biological stage, detection of operations problems such as disturbances due to storm water events etc. can be detected more easily. The report further includes other potential advantages for WWTP operation using sludge level measurement sensors like the Cerlic CBX.
AA