Department of Civil Engineering, Zhejiang University, 866 Yuhangtang Road, Hangzhou, 310058, China.
Environ Sci Pollut Res Int. 2022 Feb;29(6):8281-8293. doi: 10.1007/s11356-021-16156-8. Epub 2021 Sep 5.
Sulfide-modified nanoscale zero-valent iron (S-nZVI) has been considered an efficient material to remove heavy metals and organic contaminants. The experiments of bisphenol S (BPS) degradation by persulfate (PS) activated with S-nZVI (S-nZVI/PS) or nZVI (nZVI/PS) were carried out in this paper. The results show that, compared to the bare nZVI/PS system, the S-nZVI/PS system shows higher activity in BPS degradation, especially at high BPS concentration. The reaction rate constant k of BPS removal by the S-nZVI/PS system (0.142 min) was much higher than that in nZVI/PS system (0.089 min) because more oxidation species were generated in the S-nZVI/PS system. The results of electron paramagnetic resonance (EPR) and radical quenching tests show that both hydroxyl radical (·OH) and sulfate radical (SO) were involved in the degradation of BPS and had a great contribution to BPS removal. Moreover, the effects of S/Fe molar ratio, S-nZVI dosage, initial pH, and initial concentration of PS or BPS on S-nZVI/PS were also studied. The results show that the S/Fe molar ratio has significant influence on the BPS degradation; over 97.7% of the removal efficiency was achieved at 0.035 of S/Fe molar ratio. And the removal efficiency of BPS degradation increased with the increase of the dosage of S-nZVI, PS concentration. Furthermore, BPS could be efficiently removed in solutions with a wide range of initial pH (3.13-9.35). The observed results show that it is promising in the removal of micro-pollutants from water by persulfate activated with S-nZVI.
硫改性纳米零价铁（S-nZVI）已被认为是去除重金属和有机污染物的有效材料。本文进行了过硫酸盐（PS）活化 S-nZVI（S-nZVI/PS）或 nZVI（nZVI/PS）降解双酚 S（BPS）的实验。结果表明，与裸 nZVI/PS 体系相比，S-nZVI/PS 体系在 BPS 降解中表现出更高的活性，尤其是在高 BPS 浓度下。S-nZVI/PS 体系中 BPS 去除的反应速率常数 k（0.142 min）远高于 nZVI/PS 体系（0.089 min），因为在 S-nZVI/PS 体系中生成了更多的氧化物种。电子顺磁共振（EPR）和自由基猝灭试验的结果表明，·OH 和 SO 均参与了 BPS 的降解，对 BPS 的去除有很大的贡献。此外，还研究了 S/Fe 摩尔比、S-nZVI 用量、初始 pH 值以及 PS 或 BPS 的初始浓度对 S-nZVI/PS 的影响。结果表明，S/Fe 摩尔比对 BPS 降解有显著影响；在 S/Fe 摩尔比为 0.035 时，去除效率超过 97.7%。并且 BPS 降解的去除效率随着 S-nZVI 用量和 PS 浓度的增加而增加。此外，BPS 可以在初始 pH 值范围较宽的溶液中（3.13-9.35）有效地去除。观察到的结果表明，S-nZVI 活化过硫酸盐在去除水中的微量污染物方面具有广阔的应用前景。
