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Author      Title/Abstract      

Enhancing Copper Removal in Secondary Treatment by Chemical Addition
Author: Matthew B. Gerhardt, Diane Nascimento, Robert A. Witzgall, Michael Fan
Date: 9/302
Presented at WEFTEC 2002.

Chemical addition was tested for enhancing copper removal in the University of California, Davis (UCD) wastewater treatment plant (WWTP). Wastewater from the headworks and oxidation ditch were treated with ferric chloride and two organic precipitants in jar tests. Ferric chloride had little effect on residual dissolved copper, while the organic precipitants reduced it below 10 µg/L. In a full-scale trial, dose of 8 ppm to 13 ppm organic polymer effected a mean reduction in dissolved copper concentration of 2 µg/L, sufficient to maintain compliance with the WWTP’s 13-µg/L water quality-based effluent limit for copper. Full-scale implementation required no additional solids separation or handling equipment.