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Metal Bioavailability and Speciation in a Wetland Tailings Repository Amended with Biosolids Compost, Wood Ash, and Sulfate
Author(s) -
DeVolder Pam S.,
Brown Sally L.,
Hesterberg Dean,
Pandya Kumi
Publication year - 2003
Publication title -
journal of environmental quality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 171
eISSN - 1537-2537
pISSN - 0047-2425
DOI - 10.2134/jeq2003.8510
Subject(s) - compost , biosolids , tailings , amendment , environmental chemistry , bioavailability , chemistry , sulfate , environmental science , environmental engineering , agronomy , bioinformatics , organic chemistry , political science , law , biology
Lead poisoning of waterfowl from direct ingestion of wetland mine tailings has been reported at the Coeur d'Alene River basin in Idaho. A greenhouse study was conducted to evaluate the effects of surface applications of amendments on lead bioavailability in the tailings. Treatments included sediment only, and sediment with three different surface amendments: (i) biosolids compost plus wood ash, (ii) compost + wood ash + a low SO 2− 4 addition as K 2 SO 4 , and (iii) compost + wood ash + a high SO 2− 4 addition. Measured variables included growth and tissue Pb, Zn, and Cd concentration of arrowhead ( Sagittaria latifolia Willd.) and cattail ( Typha latifolia L.) and soil pH, redox potential (E h ), pore water Pb, Pb speciation by X‐ray absorption spectroscopy, and in vitro Pb bioavailability. The compost + ash amendment alleviated phytotoxicity for both plant species. Bioavailability of Pb as measured by a rapid in vitro extract decreased by 24 to 34% (over control) in the tailings directly below the amendment layer in the compost + SO 4 treatments. The ratio of acid volatile sulfide (AVS) to simultaneously extracted metals (SEM) also indicated a reduction in Pb bioavailability (1:40 control, 1:20 compost, 1:8 compost + low SO 4 , and 1:3 compost + high SO 4 ). Extended X‐ray adsorption fine structure (EXAFS) and X‐ray absorption near edge structure (XANES) spectroscopy data indicated that lead sulfide was greater after 99 d in the treatments that included additions of sulfate. These results indicated that, under reducing conditions, surface amendments of compost + wood ash (with or without sulfate) decreased the bioavailability of Pb in metal‐contaminated mine tailings.