Phycoremediation of Chromium (VI) by Nitella and impact of calcium encrustation.
Phycoremediation of Chromium (VI) by Nitella and impact of calcium encrustation.
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DOI：
10.1016/j.jhazmat.2008.12.055
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发表时间：
2009-07
影响因子：
13.6
通讯作者：
P. I. Gomes;T. Asaeda
中科院分区：
文献类型：
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作者：
P. I. Gomes;T. Asaeda
探讨了轮藻Nitella pseudoflabellata在不同钙化电位下修复Cr（VI）污染沃茨的适用性。它的增长被认为是正相关的Ca在水中（CaW），但在Cr（VI）在水中（CrW）的存在下，轻微显着。高钙水导致方解石结壳的植物细胞壁。从长远来看，CaW有助于Cr（VI）的固定，因为这与CaW和CrW呈正相关。而在低浓度（≤0.2mg/L）时，Ca对Cr（VI）在植物体内的被动积累有干扰作用。植物死体对Cr的吸附是主要的机制，因为植物死体中Cr的含量大于1 mg/g植物干重。Cr（VI）浓度大于0.4mg/L时，光系统II光化学的最大量子效率（Fv/Fm）值小于0.63，说明Cr（VI）浓度过高时，光系统II光化学的最大量子效率（Fv/Fm）值小于0.63。当Cr（VI）<0.2mg/L时，Fv/Fm>0.76。基于拍摄长度的伸长率曲线模式显示了类似的情况。在所有情况下，高钙铝单位与方解石结壳被认为是受铬（VI）的毒性最小。最佳的补救，获得使用高钙和铬（VI）的情况下，被动（短期）操作和低钙和铬（VI）的主动（长期）操作的组合。在被动情景下，植物积累超过1.2mg/g Cr干重，而在主动情况下，积累为0.8mg/g Cr干重。我们的结论是镍介导的铬（VI）修复是一个很有前途的技术范围内和条件的调查。
This article discusses the applicability of the Charophyte, Nitella pseudoflabellata in the remediation of Cr (VI) contaminated waters at different calcifying potentials. Its growth was found to be positively correlated with Ca in water (CaW), but marginally significant in the presence of Cr (VI) in water (CrW). High CaW resulted in calcite encrustation on the plant cell wall. CaW was found to be aiding Cr (VI) fixation in the long run, as this correlated positively with both CaW and CrW. However, Ca interfered with passive Cr (VI) accumulation in live plant matter at low CrW concentrations (≤0.2mg/L). Biosorption by dead plant matter seemed to be the major mechanism as the dead plant organs contained >1mg/g Cr dry weight of plant. Cr (VI) concentrations greater than 0.4mg/L were too toxic, showing maximum quantum efficiency of PSII photochemistry (Fv/Fm) values<0.63. The opposite was noticed (Fv/Fm>0.76) when Cr (VI) was less than 0.2mg/L. Elongation curve patterns based on shoot lengths showed similar scenarios. In all cases high CaW units with calcite encrustation found to be least affected by Cr (VI) toxicity. Optimum remediation was obtained using a combination of high Ca and Cr (VI) in the case of passive (short-term) operation and low Ca and Cr (VI) for active (long-term) operation. Under the passive scenario, plants accumulated above 1.2mg/g Cr dry weight whereas in the active case, accumulation was 0.8mg/g Cr dry weight. We conclude that Nitella-mediated Cr (VI) remediation is a promising technique within the range and conditions investigated.