Propose

In the soil environment, the existence of Cr(VI)-reducing microorganisms might affect the adsorption, desorption and reduction of Cr(VI) adsorbed on soil minerals (such as Fe oxides). The behaviour of Cr(VI)-reducing microorganisms might affect the adsorption and reduction of Cr(VI) by soil minerals.

Materials and methods

Goethite and haematite with saturated adsorbed Cr(VI) were incubated with Microbacterium sp. QH-2, a Cr(VI)-reducing bacteria. Scanning electronic microscopy (SEM) and X-ray diffraction (XRD) were used to detect the changes in goethite and haematite. X-ray absorption near-edge structure (XANES) was performed to detect the changes in Cr(III) and Cr(VI) on goethite and haematite.

Results and discussion

Strain QH-2 adhered to the surfaces of goethite and haematite. No morphological changes in goethite and haematite were detected after incubation. No secondary Fe minerals formed. Cr(III) was the dominant species of Cr on goethite and haematite (78.5% for goethite and 96.7% for haematite) after incubation. Furthermore, the reduction rate of Cr(VI) by strain QH-2 in the liquid phase was faster than that of Cr(VI) adsorbed on goethite and haematite.

Conclusions

The existence of strain QH-2 could promote the adsorption of Cr by goethite and haematite. Strain QH-2 could affect the morphological distribution and transformation of Cr in Fe oxides such as goethite and haematite.

中文翻译：

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还原Cr（VI）的细菌对针铁矿和赤铁矿吸附Cr（VI）行为的影响：形态和分布

提出

在土壤环境中，还原Cr（VI）的微生物的存在可能会影响吸附在土壤矿物（例如Fe氧化物）上的Cr（VI）的吸附，解吸和还原。还原Cr（VI）的微生物的行为可能会影响土壤矿物对Cr（VI）的吸附和还原。

材料和方法

将带有饱和Cr（VI）吸附的针铁矿和赤铁矿与Microbacterium sp。一起孵育。QH-2，一种减少Cr（VI）的细菌。扫描电子显微镜（SEM）和X射线衍射（XRD）用于检测针铁矿和赤铁矿的变化。进行X射线吸收近边缘结构（XANES），以检测针铁矿和赤铁矿中Cr（III）和Cr（VI）的变化。

结果和讨论

QH-2菌株粘附在针铁矿和赤铁矿的表面。温育后未发现针铁矿和赤铁矿的形态变化。没有形成二次铁矿物。孵化后，Cr（III）是针铁矿和赤铁矿上Cr的主要种类（针铁矿为78.5％，赤铁矿为96.7％）。此外，液相中QH-2菌株对Cr（VI）的还原速率比吸附在针铁矿和赤铁矿上的Cr（VI）还原速率快。

结论

QH-2菌株的存在可以促进针铁矿和赤铁矿对Cr的吸附。QH-2菌株可能影响Cr在针铁矿和赤铁矿等铁氧化物中的形态分布和转变。