Abstract |
Three sludge (carbon removal, nitrification and denitrification) system with alum addition for phosphorus removal was evaluated. Eight months of performance data from a 0.2 mgd pilot plant, operating with diurnal flow variations over a nominal liquid temperature range of 10 to 20C, are presented. Performance data for the soluble phase (COD, nitrogen and phosphorus), solids phase (solids characterizations and unit solids production values) and miscellaneous considerations (temperature, pH, alkalinity depletion, etc.) are also presented. Split chemical treatment with alum and optimum pH values will result in optimum system performance and the least amount of precipitated inorganic solids. Soluble phosphorus residuals as low as 0.1 mg/l can be easily achieved with an additional inorganic solids production of about 40 to 60 mg/l. (Author) |