TY - JOUR
T1 - Assessment of biochar and zero-valent iron for in-situ remediation of chromated copper arsenate contaminated soil
AU - Frick, Hanna
AU - Tardif, Stacie
AU - Kandeler, Ellen
AU - Holm, Peter E.
AU - Brandt, Kristian K.
PY - 2019/3/10
Y1 - 2019/3/10
N2 - Chromated copper arsenates (CCA) have been extensively used as wood impregnation agents in Europe and North America. Today, CCA contaminated sites remain abundant and pose environmental risks that need to be properly managed. Using a TRIAD approach that combined chemical, ecotoxicological and ecological assessment of soil quality, we investigated the abilities of biochar and zero-valent iron (ZVI) to remediate CCA contaminated soil in a microcosm experiment. Soil samples from a highly contaminated CCA site (1364, 1662 and 540 μg g−1 of As, Cu and Cr, respectively) were treated with two different biochars (fine and coarse particle size; 1% w w−1) and ZVI (5% w w−1), both as sole and as combined treatments, and incubated for 56 days at 15 °C. In general, bioavailable As (Asbio) and Cu (Cubio) determined by whole-cell bacterial bioreporters corresponded well to water-extractable As and Cu (Aswater and Cuwater). However, in biochar treatments, only Cubio and not Cuwater was significantly reduced. In contrast, under ZVI treatments only Cuwater and not Cubio was reduced, demonstrating the value of complementing analytical with bacterial bioreporter measurements to infer bioavailability of elements to soil microorganisms. The combined fine particle size biochar and ZVI treatment effectively reduced water extractable concentrations of Cr, Cu, and As on site by 45%, 45% and 43% respectively, and led to the highest ecological recovery of the soil bacterial community, as measured using the [3H]leucine incorporation technique. We conclude that the combined application of biochar and ZVI as soil amendments holds promise for in-situ stabilization of CCA contaminated sites.
AB - Chromated copper arsenates (CCA) have been extensively used as wood impregnation agents in Europe and North America. Today, CCA contaminated sites remain abundant and pose environmental risks that need to be properly managed. Using a TRIAD approach that combined chemical, ecotoxicological and ecological assessment of soil quality, we investigated the abilities of biochar and zero-valent iron (ZVI) to remediate CCA contaminated soil in a microcosm experiment. Soil samples from a highly contaminated CCA site (1364, 1662 and 540 μg g−1 of As, Cu and Cr, respectively) were treated with two different biochars (fine and coarse particle size; 1% w w−1) and ZVI (5% w w−1), both as sole and as combined treatments, and incubated for 56 days at 15 °C. In general, bioavailable As (Asbio) and Cu (Cubio) determined by whole-cell bacterial bioreporters corresponded well to water-extractable As and Cu (Aswater and Cuwater). However, in biochar treatments, only Cubio and not Cuwater was significantly reduced. In contrast, under ZVI treatments only Cuwater and not Cubio was reduced, demonstrating the value of complementing analytical with bacterial bioreporter measurements to infer bioavailability of elements to soil microorganisms. The combined fine particle size biochar and ZVI treatment effectively reduced water extractable concentrations of Cr, Cu, and As on site by 45%, 45% and 43% respectively, and led to the highest ecological recovery of the soil bacterial community, as measured using the [3H]leucine incorporation technique. We conclude that the combined application of biochar and ZVI as soil amendments holds promise for in-situ stabilization of CCA contaminated sites.
KW - Bioavailability
KW - Biochar
KW - Metal-contaminated soils
KW - Soil remediation
KW - Whole-cell biosensors
KW - Zero-valent iron
UR - http://www.scopus.com/inward/record.url?scp=85056884761&partnerID=8YFLogxK
U2 - 10.1016/j.scitotenv.2018.11.193
DO - 10.1016/j.scitotenv.2018.11.193
M3 - Journal article
C2 - 30472643
AN - SCOPUS:85056884761
SN - 0048-9697
VL - 655
SP - 414
EP - 422
JO - Science of the Total Environment
JF - Science of the Total Environment
ER -