A collaborative system of carboxymethyl cellulose stabilized nanosized zero-valent iron (CMC-nFe0) and microorganisms was set up to enhance the stabilization of Cr(VI) in soil. In comparison with an aqueous-bound Cr(VI) removal of 18.9% in the nFe0 system, a higher Cr(VI) removal of 68.9% was achieved in the nFe0 and microorganisms system after 14 d remediation because the microorganisms on the nFe0 surface promoted nFe0 corrosion and enhanced abiotic and biotic Cr(VI) stabilization by generating highly active minerals such as magnetite, lepidocrocite and green rust on the nFe0 surface. As a stabilizing agent for nFe0 and an organic substrate for microorganisms, CMC on the nFe0 surface not only enhanced the dispersion of nFe0, but also boosted the activity of microorganisms, resulting in a promotion of 0.9 and 0.5 times higher aqueous-bound Cr(VI) removal via the improvement of nFe0 and microorganisms respectively, thus a total 4 times higher aqueous-bound Cr(VI) removal of 95.3% was achieved in the CMC-nFe0 and microorganisms system as compared to the nFe0 system. After 14 d remediation, easily available species of Cr(VI) and Crtotal, such as water soluble (WS), exchangeable (EX) and bounded to carbonates (CB), were mainly transformed to less available Fe-Mn oxides-bounded (OX) and residual (RS) species because of the production of ferrochrome precipitates (CrxFe1-xOOH or CrxFe1-x(OH)3). Besides, the stabilization of Cr(VI) in the CMC-nFe0 and microorganisms system was pH-dependent and it increased with CMC-nFe0 dosage. Due to excellent Cr(VI) stabilization and Cr immobilization, coupled CMC-nFe0 and anaerobic microorganisms process is of great potential in remediating Cr(VI)-containing soil.

中文翻译：

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羧甲基纤维素稳定的纳米Fe0（CMC-nFe0）和混合厌氧微生物增强了土壤中的Cr（VI）稳定性。

建立了羧甲基纤维素稳定的纳米零价铁（CMC-nFe0）和微生物的协同体系，以增强土壤中Cr（VI）的稳定性。与在nFe0系统中水结合的Cr（VI）去除率为18.9％相比，经过14 d的修复，nFe0和微生物系统中的Cr（VI）去除率更高，达到68.9％，因为nFe0表面上的微生物被促进了。通过在nFe0表面生成诸如磁铁矿，纤铁矿和绿锈等高活性矿物，nFe0腐蚀并增强了非生物和生物Cr（VI）的稳定性。作为nFe0的稳定剂和微生物的有机底物，nFe0表面的CMC不仅增强了nFe0的分散性，而且还增强了微生物的活性，从而提高了0.9和0。通过改善nFe0和微生物分别去除结合在水中的Cr（VI）的5倍，因此，与CMC-nFe0和微生物系统相比，结合CMC-nFe0和微生物系统去除结合在水中的Cr（VI）的总和高出4倍，达到95.3％。 nFe0系统。修复14天后，易获得的Cr（VI）和Crtotal物种，例如水溶性（WS），可交换（EX）和与碳酸盐（CB）结合，主要转化为难于利用的Fe-Mn氧化物结合（OX ）和残留（RS）物种，因为产生了铬铁沉淀（CrxFe1-xOOH或CrxFe1-x（OH）3）。此外，CMC-nFe0和微生物系统中Cr（VI）的稳定性是pH依赖性的，并随CMC-nFe0剂量的增加而增加。由于出色的Cr（VI）稳定性和Cr固定性，