Conditioning and Dewatering of Anaerobically Digested BPR Sludge

Abstract

Anaerobic digestion of sludge from a full‐scale biological phosphorus removal (BPR) treatment facility resulted in significant release of soluble phosphorus. However, the increase in phosphorus and/or change in microbial population associated with the BPR conversion had no significant impact on sludge dewatering characteristics. Cationic polymer requirements (Percol 757) for effective sludge conditioning were not significantly impacted by the conversion to BPR treatment. Inorganic chemical addition using both lime and ferric chloride promoted effective sludge conditioning while concurrently promoting the reduction in filtrate phosphorus concentration. Suggestions for implementing the experimental results in full‐scale sludge treatment systems are also presented.