PARENT SESSION
70 - Metal Pollution: From Exposure to Ecological Effects
8:00 AM to 6:30 PM, Wednesday, 15 May 2002
Exhibition Area

(70-72) Design of a Constructed Wetland for Remediation of Bioavailable Copper in a Wastestream.

Murray-Gulde, Cynthia^*,1, Rodgers, John¹, Huddleston, George², ¹ Clemson Institute of Environmental Toxicology, Pendleton, SC² Fouser Environmental Services, Versailles, KY

ABSTRACT- Performance was evaluated for a full-scale constructed wetland treatment system recently constructed for treatment of a copper contaminated wastewater stream. Design of the full-scale system involved theoretical and physical modeling of the constructed wetland system, with the primary objective of poising the system to limit copper bioavailability. Performance objectives for this constructed wetland treatment system were to decrease total recoverable copper to <22 g/L and to eliminate toxicity (Ceriodaphnia dubia; 7-d, static/renewal). Evaluation of the physical model indicated overall copper removal from the simulated wastewater used in the pilot studies was 73% (±14) with the inflow total recoverable copper concentrations averaging 46(±9) g Cu/L while average outflow copper concentrations were 12 (±7) g Cu/L following a 48-h HRT. Pilot-scale copper inflow water was toxic to C. dubia, while no toxicity was observed in the outflow. Monitoring of the full-scale system began in spring 2001 and continues. Inflow wastewaster concentrations averaged 27 (± 11) g Cu/L and outflow averaged 3 (±2) g Cu/L, with 89% (±8) overall copper removal. Inflow water was toxic to C. dubia, while no toxicity was observed in outflow water. Hydrosoil redox potential and AVS indicated that the system was poised to limit bioavailable copper, with no adverse seasonal effects on wetland performance.

Key words: Constructed wetland, copper, AVS, bioavailability