State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, East China University of Science and Technology, Shanghai 200237, China; Department of Environmental Sciences, The University of Lahore, Lahore 46000, Pakistan.
State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, East China University of Science and Technology, Shanghai 200237, China.
Sci Total Environ. 2021 Nov 10;794:148674. doi: 10.1016/j.scitotenv.2021.148674. Epub 2021 Jun 25.
A novel catalyst of sulfidated iron-nickel supported on biochar (S-FeNi@BC) was synthesized to activate persulfate (PS) for the removal of trichloroethylene (TCE). A number of techniques including XRD, SEM, TEM, FTIR, BET and EDS were employed to characterize S-FeNi@BC. The influence of sulfur to iron ratio (S/F) on TCE removal was investigated by batch experiments and a higher TCE removal (98.4%) was achieved at 0.22/1 ratio of S/F in the PS/S-FeNi@BC oxidation system. A dominant role in iron species conversion was noticed by the addition of sulfur in FeNi@BC system. Significant enhancement in recycling of the dissolved and surface Fe(II) was confirmed which contributed to the generation of free and surface-bound active radical species (OH, O, O, SO). Further, the presence and contribution of these radicals were validated by the electron paramagnetic resonance (EPR) and quenching study. In addition, XPS results demonstrated the dominant role of S(-II) with the increase of Fe(II) from 36.3% to 58.6% and decrease of Fe(III) from 52.1% to 39.8% in the PS/S-FeNi@BC system. In crux, the influence of initial pH, catalyst dosage, oxidant dosage, and inorganic ions (HCO, Cl, NO and SO) on TCE removal was also investigated. The findings obtained from this study suggest that S-FeNi@BC is an appropriate catalyst to activate PS for TCE contaminated groundwater remediation.
一种新型的负载在生物炭上的硫化铁-镍催化剂（S-FeNi@BC）被合成用来激活过硫酸盐（PS）以去除三氯乙烯（TCE）。采用 XRD、SEM、TEM、FTIR、BET 和 EDS 等多种技术对 S-FeNi@BC 进行了表征。通过批实验考察了硫铁比（S/F）对 TCE 去除的影响，在 PS/S-FeNi@BC 氧化体系中，S/F 比为 0.22/1 时，TCE 的去除率最高，达到 98.4%。在 FeNi@BC 体系中添加硫对铁物种的转化起着主导作用。证实了溶解态和表面态 Fe(II)的循环显著增强，这有助于生成游离和表面结合的活性自由基物种（OH、O、O 和 SO）。此外，通过电子顺磁共振（EPR）和猝灭实验验证了这些自由基的存在和贡献。此外，XPS 结果表明，随着 PS/S-FeNi@BC 体系中 Fe(II)从 36.3%增加到 58.6%，Fe(III)从 52.1%减少到 39.8%，S(-II)的作用占主导地位。总之，还研究了初始 pH 值、催化剂用量、氧化剂用量以及无机离子（HCO、Cl、NO 和 SO）对 TCE 去除的影响。本研究结果表明，S-FeNi@BC 是一种合适的催化剂，可以激活 PS 来修复受 TCE 污染的地下水。
