TY - JOUR
T1 - Algae as an electron donor promoting sulfate reduction for the bioremediation of acid rock drainage
AU - Ayala-Parra, Pedro
AU - Sierra-Alvarez, Reyes
AU - Field, Jim A.
N1 - Funding Information:
Further evidence of sulfate reduction is supported by the removal of sulfate in the algae-amended columns ( Fig. 2 B). The highest sulfate removal occurred from the latter part of period (b) to the end of period (d) in the WCA column, or from period (c) through (e) in the LEA column, corresponding to 60–80% sulfate removal. There was little to no sulfate removal in the endogenous column.
Funding Information:
This work was funded by a grant from the National Institute of Environmental Health Sciences-supported Superfund Research Program (NIH ES-04940). P. Ayala-Parra was partly supported by the Mexican National Council of Science and Technology (CONACYT). We are grateful to Dr. Kimberly Ogden for the algal biomass provided and to Dr. Sue A. Roberts for XRD analysis.
PY - 2016/11/5
Y1 - 2016/11/5
N2 - This study assessed bioremediation of acid rock drainage in simulated permeable reactive barriers (PRB) using algae, Chlorella sorokiniana, as the sole electron donor for sulfate-reducing bacteria. Lipid extracted algae (LEA), the residues of biodiesel production, were compared with whole cell algae (WCA) as an electron donor to promote sulfate-reducing activity. Inoculated columns containing anaerobic granular sludge were fed a synthetic medium containing H2SO4 and Cu2+. Sulfate, sulfide, Cu2+ and pH were monitored throughout the experiment of 123 d. Cu recovered in the column packing at the end of the experiment was evaluated using sequential extraction. Both WCA and LEA promoted 80% of sulfate removal (12.7 mg SO42- d-1) enabling near complete Cu removal (>99.5%) and alkalinity generation raising the effluent pH to 6.5. No noteworthy sulfate reduction, alkalinity formation and Cu2+ removal were observed in the endogenous control. In algae amended-columns, Cu2+ was precipitated with biogenic H2S produced by sulfate reduction. Formation of CuS was evidenced by sequential extraction and X-ray diffraction. LEA and WCA provided similar levels of electron donor based on the COD balance. The results demonstrate an innovative passive remediation system using residual algae biomass from the biodiesel industry.
AB - This study assessed bioremediation of acid rock drainage in simulated permeable reactive barriers (PRB) using algae, Chlorella sorokiniana, as the sole electron donor for sulfate-reducing bacteria. Lipid extracted algae (LEA), the residues of biodiesel production, were compared with whole cell algae (WCA) as an electron donor to promote sulfate-reducing activity. Inoculated columns containing anaerobic granular sludge were fed a synthetic medium containing H2SO4 and Cu2+. Sulfate, sulfide, Cu2+ and pH were monitored throughout the experiment of 123 d. Cu recovered in the column packing at the end of the experiment was evaluated using sequential extraction. Both WCA and LEA promoted 80% of sulfate removal (12.7 mg SO42- d-1) enabling near complete Cu removal (>99.5%) and alkalinity generation raising the effluent pH to 6.5. No noteworthy sulfate reduction, alkalinity formation and Cu2+ removal were observed in the endogenous control. In algae amended-columns, Cu2+ was precipitated with biogenic H2S produced by sulfate reduction. Formation of CuS was evidenced by sequential extraction and X-ray diffraction. LEA and WCA provided similar levels of electron donor based on the COD balance. The results demonstrate an innovative passive remediation system using residual algae biomass from the biodiesel industry.
KW - Acid mine drainage
KW - Algae waste
KW - Biodiesel
KW - Heavy metal
KW - Permeable reactive barrier
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U2 - 10.1016/j.jhazmat.2016.06.011
DO - 10.1016/j.jhazmat.2016.06.011
M3 - Article
C2 - 27318730
AN - SCOPUS:84974827266
VL - 317
SP - 335
EP - 343
JO - Journal of Hazardous Materials
JF - Journal of Hazardous Materials
SN - 0304-3894
ER -