ABSTRACT
With the accelerated urbanization process, the accumulation of stored sludge in wastewater treatment plants is increasing year by year, and the stored sludge is likely to pose a potential and long-term threat to the surrounding environment. To identify the pollution characteristics of stored sludge sources and to analyze the changes in the physicochemical properties of stored sludge at different storage times, this study sampled sludge stored in a sludge storage site in north China for nearly ten years and analyzed its moisture content, pH value, TOC, TN, TP, TK. The results showed that all the indicators showed different downward trends with the increase in storage time. The moisture content decreased by 14.4 %. The pH value decreased from 7.3 to 6.9, and the overall sludge was weakly alkaline. The TOC content decreased significantly, from 286.4 g/kg to 171.3 g/kg. The TN, TP, and TK content decreased in the range of 50.1~20.3 g/kg, 29.1~25.3 g/kg, and 8.4~4.9 g/kg.
