Zhang Runyuan, Zhang Nuanqin, Fang Zhanqiang
School of Chemistry and Environment, South China Normal University, Guangzhou, Guangdong 510006, China and Guangdong Technology Research Center for Ecological Management and Remediation of Urban Water System, Guangzhou, Guangdong 510006, China E-mail:
Water Sci Technol. 2018 Mar;77(5-6):1622-1631. doi: 10.2166/wst.2018.039.
In this study, the remediation experiments were performed outdoors in natural conditions. Carboxymethyl cellulose (CMC)-stabilized nanoscale zero-valent iron (CMC-nZVI), biochar (BC) and CMC-stabilized nanoscale zero-valent iron composited with biochar (CMC-nZVI/BC) were synthesized and investigated for their effect on the in situ remediation of hexavalent chromium [Cr(VI)] contaminated soil and the concentration of available iron was tested after the remediation, compared with the untreated soil. The results of toxicity characteristic leaching procedure (TCLP) test showed that CMC-nZVI and CMC-nZVI/BC used as remediation materials could obviously improve the remediation rate of Cr contaminated soil and when the ratio of CMC-nZVI to Fe was 2.5 g/Kg, the leachability of Cr(VI) and Cr can be reduced by 100% and 95.8% simultaneously. Moreover, sequential extraction procedure (SEP) showed that most exchangeable Cr converted to carbonate-bound and Fe-Mn oxides-bound, reducing the availability and leachability of Cr in the soil.
在本研究中，修复实验在自然条件下于户外进行。合成了羧甲基纤维素（CMC）稳定的纳米零价铁（CMC-nZVI）、生物炭（BC）以及羧甲基纤维素稳定的纳米零价铁与生物炭的复合材料（CMC-nZVI/BC），并研究了它们对六价铬[Cr(VI)]污染土壤原位修复的效果，修复后测试了有效铁的浓度，并与未处理土壤进行比较。毒性特性淋溶程序（TCLP）测试结果表明，用作修复材料的CMC-nZVI和CMC-nZVI/BC能显著提高铬污染土壤的修复率，当CMC-nZVI与铁的比例为2.5 g/Kg时，Cr(VI)和Cr的淋溶性可同时降低100%和95.8%。此外，连续提取程序（SEP）表明，大部分可交换态铬转化为碳酸盐结合态和铁锰氧化物结合态，降低了土壤中铬的有效性和淋溶性。
