Evaluation of a constructed wetland treatment system specifically designed to decrease bioavailable copper in a wastestream.
A specifically designed constructed wetland decreased copper concentrations in a wastestream to 22 microg Cu/L and eliminated associated toxicity. Metal toxicity is a function of both concentration and form. This research measured copper partitioning to ligands within the wetland and observed changes in copper form with regard to bioavailability. Average monthly copper concentrations in the constructed wetland treatment system ranged from 10 to 47 microg/L in the upstream (i.e., inflow to the constructed wetland prior to the retention basin) and from non-detection to 11 microg/L in the downstream (i.e., outflow to the receiving stream). On average, 78% total-recoverable, 85% acid-soluble, and 83% soluble copper were removed from inflow to outflow of this constructed wetland; however, total recoverable and acid-soluble copper measurements were not useful indicators of bioavailable copper. Survival of Ceriodaphnia dubia increased from an average of 2% survival in the inflow to 96% in the outflow and reproduction increased from an average of 8 to 24 neonates/female, respectively. Soluble copper is a more accurate predictor of the concentration at which effects were observed. Average ratio of acid volatile sulfides to simultaneously extractable metals was 1.4: 0.06 micromol/g indicating sufficient sulfides to sequester available metals in the system.
Murray-Gulde
Cynthia L
CL
ENTRIX, Inc., 621 North Ave. NE, Suite A-125, Atlanta, GA 30308, USA. cgulde@entrix.com
Bearr
Jonathan
J
Rodgers
John H
JH
D000818:Animals; D001682:Biological Availability; D003300:Copper / Q000737:chemistry / Q000302:isolation & purification* / Q000633:toxicity*; D003621:Daphnia / Q000502:physiology*; D005618:Fresh Water / Q000737:chemistry; D007287:Inorganic Chemicals / Q000302:isolation & purification; D009942:Organometallic Compounds / Q000302:isolation & purification; D010084:Oxidation-Reduction; D012098:Reproduction / Q000187:drug effects; D012621:Seasons; D012989:Soil Pollutants / Q000032:analysis; D013440:Sulfides / Q000032:analysis; D016019:Survival Analysis; D014865:Waste Disposal, Fluid; D014874:Water Pollutants, Chemical / Q000302:isolation & purification* / Q000633:toxicity*
D007287:Inorganic Chemicals; D009942:Organometallic Compounds; D012989:Soil Pollutants; D013440:Sulfides; D014874:Water Pollutants, Chemical; D003300:Copper