Immobilization of Cd in river sediments by sodium alginate modified nanoscale zero-valent iron: Impact on enzyme activities and microbial community diversity
Immobilization of Cd in river sediments by sodium alginate modified nanoscale zero-valent iron: Impact on enzyme activities and microbial community diversity
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海藻酸钠改性纳米零价铁固定河流沉积物中的镉：对酶活性和微生物群落多样性的影响
DOI：
10.1016/j.watres.2016.09.050
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发表时间：
2016-12-01
期刊：
影响因子：
12.8
通讯作者：
Xu, Piao
中科院分区：
文献类型：
--
作者：
Huang, Danlian;Xue, Wenjing;Xu, Piao
本文研究了海藻酸钠(SA)修饰的纳米零价铁(NZVI)在修复镉(Cd)污染河流沉积物中的建设性作用。观察了SNZVI处理对土壤Cd含量、酶活性(尿素酶、过氧化氢酶、脱氢酶)和细菌群落结构的影响。连续提取实验表明，随着Cd的生物有效性降低，Cd的大部分流动态被转化为残留物(在0.1wt%SA孵育30d后，Cd的最大残留率从15.49%增加到57.28%)。除脱氢酶外，其余两种酶的活性均随培养时间的延长而增强，表明SNZVI产生的铁离子对脱氢酶有抑制作用，而对其他酶无明显抑制作用。利用聚合酶链式反应变性梯度凝胶电泳法(PCR-DGGE)检测微生物群落的变化，结果表明SNZVI和NZVI能增加细菌类群，提高细菌丰度。这项研究的所有实验结果都为SNZVI处理对污染河流沉积物中金属Cd固定的潜在后果提供了新的见解。(C)2016爱思唯尔有限公司。保留所有权利。
This paper investigated how sodium alginate (SA)-modified nanoscale zero-valent iron (NZVI), play a constructive role in the remediation of cadmium (Cd) contaminated river sediments. The changes of the fraction of Cd, enzyme activities (urease, catalase, dehydrogenase) and bacterial community structures with the treatment by SNZVI were observed. The sequential extraction experiments demonstrated that most mobile fractions of Cd were transformed into residues (the maximum residual percentage of Cd increases from 15.49% to 57.28% after 30 days of incubation at 0.1 wt% SA), with the decrease of bioavailability of Cd. Exclusive of dehydrogenase, the activities of the other two enzymes tested were enhanced with the increase of incubation time, which indicated that dehydrogenase might be inhibited by ferric ions formed from SNZVI whereas no obvious inhibition was found for other enzymes. Polymerase chain reaction denaturing gradient gel electrophoresis (PCR-DGGE) analyses were used for the detection of microbial community changes, and the results showed that SNZVI and NZVI could increase bacterial taxa and improve bacterial abundance. All the experimental findings of this study provide new insights into the potential consequences of SNZVI treatments on the metal Cd immobilization in contaminated river sediments. (C) 2016 Elsevier Ltd. All rights reserved.