Remediation of Trichloroethylene-Contaminated Groundwater by Sulfide-Modified Nanoscale Zero-Valent Iron Supported on Bi
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Remediation of Trichloroethylene-Contaminated Groundwater by Sulfide-Modified Nanoscale Zero-Valent Iron Supported on Biochar: Investigation of Critical Factors Jie Chen & Haoran Dong & Ran Tian & Rui Li & Qianqian Xie Received: 18 May 2020 / Accepted: 23 July 2020 # Springer Nature Switzerland AG 2020
Abstract This study investigated the feasibility and mechanism of sulfide-modified nanoscale zero-valent iron supported on biochar (S-nZVI@BC) for the removal of TCE in the scenario of groundwater remediation. The effects of some critical factors, including pyrolysis temperature of biochar, mass ratio of S-nZVI to BC, initial pH, typical groundwater compositions, co-contaminants, and particle aging time, on the TCE removal were examined. The results revealed that the different pyrolysis temperatures could change physicochemical properties of BC, which influenced the TCE adsorption and degradation by S-nZVI@BC. The mass ratio of SnZVI to BC could determine the extent of adsorption and degradation of TCE. The total removal of TCE was not significantly influenced by the initial pH (3.0–9.0), but the degradation of TCE was enhanced at higher pH. Notably, the typical anions (SO42−, HCO3−, and HPO42 − ), humic acid, and co-contaminants (Cr(VI) and NO3−) in groundwater all slightly influenced the total removal of TCE, but markedly inhibited its degradation. Electronic supplementary material The online version of this article (https://doi.org/10.1007/s11270-020-04797-3) contains supplementary material, which is available to authorized users. J. Chen : H. Dong : R. Tian : R. Li : Q. Xie College of Environmental Science and Engineering, Hunan University, Changsha 410082 Hunan, China J. Chen : H. Dong (*) : R. Tian : R. Li : Q. Xie Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082 Hunan, China e-mail: [email protected]
Additionally, after exposure to air over different times (5 days, 10 days, 20 days, and 30 days), the reactivity of S-nZVI@BC composites was apparently decreased due to surface passivation. Nevertheless, the aged SnZVI@BC composites still maintained relative high removal and degradation of TCE when the reaction time prolonged. Overall, the results showed that the SnZVI@BC, combining the high adsorption capacity of BC and the high reductive capacity of S-nZVI, had a much better performance than the single S-nZVI or BC, suggesting that S-nZVI@BC is one promising material for the remediation of TCE-contaminated groundwater. Keywords Adsorption . Biochar . Degradation . Groundwater pollution . Nanoscale zero-valent iron . Trichloroethylene
1 Introduction Recently, sulfide-modified nanoscale zero-valent iron (S-nZVI), as a popular alternative to overcome the limitations (e.g., agglomeration and passivation) and maximize the benefits of nZVI particles, has attracted broad attention (Fan et al. 2016; Dong et al. 2018; Wang et al. 2020). S-nZVI has superior adsorption performance and high reducing activity towards a large-scope of contaminants, incl
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