Chlorinated solvent degradation in groundwater by green rust-bone char composite: solute interactions and chlorinated ethylene competition
Research output: Contribution to journal › Journal article › Research › peer-review
Biochar works as a green catalyst for the dechlorination of chlorinated ethylenes (CEs) by green rust (GR). Although the GR-biochar composite shows great potential for groundwater remediation, its performance under simulated field conditions has not been investigated. In this study, a composite of chloride GR and bone char (BC) was used to investigate the effect of groundwater solutes (Cl-, SO42-, HCO3-, and H4SiO4) and the co-existence of one or two CE(s) on GR-BC reactivity with CEs. Furthermore, a contaminant-free groundwater and five CE-contaminated groundwaters were collected to test the reactivity of the GR-BC composite under real groundwater conditions. Among all tested groundwater solutes, HCO3- affected CE dechlorination rates the most, exemplified by a 6.7-fold decrease in trichloroethylene (TCE) reduction rate constant, k(mass), to 0.16 L g(-1) h(-1) in the presence of 10 mM HCO3- solution when compared to the solute free experiment. Silicic acid led to a 1.7-fold decrease in k(mass) at concentrations of 0.5 and 1 mM and a 5.3-fold decrease at 2 mM. TCE reduction rate was also decreased by the co-existence of PCE (by a factor of 1.6), while cDCE had very little impact. Natural groundwater matrices led to up to 52-fold decrease in k(mass)(TCE), depending on the complexity and pollutant profile of the groundwater. However, relatively fast dechlorination with k(mass)(TCE) >= 0.021 L g(-1) h(-1) was seen in all tested CE-contaminated groundwaters where CE concentrations were comparable. For hard groundwaters, HCO3- is recognized as the main inhibitor for dechlorination, while the impact of the other tested solutes is minor. The study provides practical information for the application of the GR-BC composite for remediation of CE-contaminated groundwaters.
Original language | English |
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Journal | Environmental Science: Water Research & Technology |
Volume | 7 |
Issue number | 11 |
Pages (from-to) | 2043-2053 |
Number of pages | 11 |
ISSN | 2053-1400 |
DOIs | |
Publication status | Published - 2021 |
- ZEROVALENT IRON NZVI, ZERO-VALENT IRON, REDUCTION, WATER, TRANSFORMATION, PHOSPHATE, COPRECIPITATION, REACTIVITY, CARBONATE, GOETHITE
Research areas
ID: 280286110