THE USE OF POLYMER AND PAPER PULP AS CONDITIONING AGENTS FOR MUNICIPAL WASTEWATER TREATMENT PLANT SLUDGE PROCESSING

Substituting polymer and paper pulp for lime and ferric chloride, to condition municipal wastewater treatment plant sludge was evaluated, and ultimately implemented as a method to improving the efficiency of plate and frame filter press and incinerator operation. The evaluation and subsequent implementation of these sludge conditioning agents was performed at the Erie County – Southtowns Advanced Wastewater Treatment Plant in Hamburg, New York. The plant is a 16-mgd pure oxygen activated sludge plant with biological phosphorus removal. While maintaining a constant polymer dosage, varying quantities of paper pulp were added to the liquid sludge to determine the optimal sludge-to-paper pulp ratio. The impact of paper pulp and polymer-conditioned sludge on plant operations was evaluated with respect to filter press throughput, overall incinerator combustion quality and efficiency, ash quantity/quality and air emissions.When compared to sludge conditioned with lime and ferric chloride, the polymer and paper pulp-conditioned sludge had similar cake release and feed characteristics, had higher BTU values, required less auxiliary fuel for incineration, and generated less ash for disposal. The polymer and paper pulp did not have any appreciable negative impact on the operation of the plant. Construction of the recommended sludge conditioning facilities was completed in winter 1999, with full-scale start-up commencing in June 2000. Estimated cost savings in processing sludge conditioned with polymer and paper pulp were estimated to be 25 per dry ton of sludge solids, including the cost of the new facilities, which equates to an annual savings of about 51,000. The estimated operations and maintenance cost savings is approximately 69 per dry ton of sludge solids.