MASSBALANSER OCH RENINGSEFFEKTER AVSEENDE NÅGRA METALLER VID LUNDS RENINGSVERK / Mass Balances and Removal Efficiencies of Some Heavy Metals at the Sewage Treatment Plant in Lund
Samples of incoming raw sewage vater have been collected on a five day basis every week during six months, and analyzed for seven heavy metals. A few determinations of other elements have also been made. These data have been combined with the results of the compulsory analytical control of effluent water and sludge to calculate mass balances and removal efficiencies. It is suggested that the accuracy of sampling procedures and mass flow measurements is demonstrated by showing the closure of the mass balance for phosphorous. There is a considerable variation in the composion of the raw sewage water. Based on five days composite samples, the relative standard deviation is at east about 20 % for the most abundant metals (copper, zinc), but rises to 50 % or more for several of the other elements. Therefore, mass balance studies should be performed during an extended period of time to diminish the effect of random variations “Complete abstract not presented.”