地下水常见阴离子影响双重改性纳米零价铁降解硝基苯的机制及效果

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中图分类号：X523 文献标志码：A

Abstract： Sulfide and carboxymethyl cellulose （CMC） stabilization dual-modified nano zero-valent iron（S-CMC-nZVI） exhibits high reactivity and strong mobility，demonstrating significant potential for remediating organically contaminated groundwater. However， the effects of common groundwateranions on its surface-modified layer and contaminant degradation performance remains unclear. This study investigated the mechanisms and effects of common groundwater anions （ SO42- ， HCO3- ， NO3- ， Cl- ） on the degradation of nitrobenzene by S-CMC-nZVI ， using nitrobenzene as the target pollutant. The results showed that the presence of NO3- and Cl- did not affect the sulfidation degree of the S-CMC- ΩnZVI surface modified layer or the degradation efficiency of nitrobenzene. The addition of SO42- or （204号 HCO3- led to a reduction in the sulfidation degree of the surface modification layer，causing peling and increase in the content of Fe2+ and S2- in the solution. Consequently，the actual n（S）/n （Fe）molar ratios of the material decreased to O.O13 2 and O.019 1，respectively. The FeS and Fe2+ produced by the peeling of the sulfide layer can promote the degradation of nitrobenzene. However， SO42- will cause the formation of iron oxides on the surface of S-CMC-nZVI ， thereby inhibiting the sustained degradation of nitrobenzene. In contrast， HCO3- accelerated the decomposition of the oxide layer，facilitating the sustained degradation of nitrobenzene，with a maximum efficiency of 99.6% . This study provides a theoretical reference for the efficient application of S-CMC-nZVI in groundwater remediation.

Key words： groundwater;anion; S-CMC-nZVI ；nitrobenzene

0 引言

纳米零价铁（nanoscalezero-valentiron，nZVI具有比表面积大、表面活性高、还原性强等优点，可广泛应用于去除重金属[]、卤代有机物[2]、硝酸盐[3]、硝基芳烃[4]等污染物。（剩余18532字）