Open AccessWheat straw biochar-supported nanoscale zerovalent iron for removal of trichloroethylene from groundwater
Author(s) -
Hui Li,
Ya Qin Chen,
Shuai Chen,
Xiao Li Wang,
Shuyu Guo,
Yue Qiu,
Yong Di Liu,
Xiao Li Duan,
Yun Jiang Yu
Publication year - 2017
Publication title -
plos one
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.99
H-Index - 332
ISSN - 1932-6203
DOI - 10.1371/journal.pone.0172337
Subject(s) - biochar , trichloroethylene , zerovalent iron , chemistry , environmental remediation , straw , environmental chemistry , humic acid , permeable reactive barrier , reductive dechlorination , pyrolysis , nuclear chemistry , chloride , adsorption , reactivity (psychology) , contamination , inorganic chemistry , biodegradation , organic chemistry , fertilizer , medicine , ecology , alternative medicine , pathology , biology
This study synthesized the wheat straw biochar-supported nanoscale zerovalent iron (BC-nZVI) via in-situ reduction with NaBH 4 and biochar pyrolyzed at 600°C. Wheat straw biochar, as a carrier, significantly enhanced the removal of trichloroethylene (TCE) by nZVI. The pseudo-first-order rate constant of TCE removal by BC-nZVI (1.079 h −1 ) within 260 min was 1.4 times higher and 539.5 times higher than that of biochar and nZVI, respectively. TCE was 79% dechlorinated by BC-nZVI within 15 h, but only 11% dechlorinated by unsupported nZVI, and no TCE dechlorination occurred with unmodified biochar. Weakly acidic solution (pH 5.7–6.8) significantly enhanced the dechlorination of TCE. Chloride enhanced the removal of TCE, while SO 4 2− , HCO 3 − and NO 3 − all inhibited it. Humic acid (HA) inhibited BC-nZVI reactivity, but the inhibition decreased slightly as the concentration of HA increased from 40 mg∙L -1 to 80 mg∙L -1 , which was due to the electron shutting by HA aggregates. Results suggest that BC-nZVI was promising for remediation of TCE contaminated groundwater.