A novel hybrid nano zerovalent iron initiated oxidation - Biological degradation approach for remediation of recalcitrant waste metalworking fluids
A novel hybrid nano zerovalent iron initiated oxidation - Biological degradation approach for remediation of recalcitrant waste metalworking fluids
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DOI：
10.1016/j.watres.2012.02.006
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发表时间：
2012-05-01
期刊：
影响因子：
12.8
通讯作者：
Thompson, Ian P.
中科院分区：
文献类型：
--
作者：
Jagadevan, Sheeja;Jayamurthy, Manickam;Thompson, Ian P.
通过生物途径处理操作耗尽的金属加工液(MWF)是一个有吸引力的选择，因为它以相对较低的能源需求有效。然而，这是极具挑战性的，因为这些液体的化学成分很复杂，包括添加有毒的杀生剂，这些杀虫剂是在液体运行时专门添加的，以延缓生物退化。纳米元素铁代表了新一代环境修复技术。采用一种新的混合法对半合成金属加工液(MWF)废水进行了实验室规模的批量研究，以测试该废水的降解能力。方法是结合纳米零价铁(NZVI)诱导的氧化和随后的生物降解的协同效应，特别是修复MWF废水中的顽固性成分。在含氧废水中加入nZVI颗粒会导致存在的有机污染物被氧化。我们的研究证实，在pH 3.0和中性pH(7.5)条件下，nZVI氧化降低了78%的化学需氧量(COD)和67%的降低，同时毒性降低了85%。重要的是，这种低毒性使nZVI处理后的出水更适合第二阶段生物氧化步骤。新型组合处理工艺的COD总降解率为95.5%，表明nZVI氧化技术可用于提高难降解废水的可生化性。(C)2012爱思唯尔有限公司。保留所有权利。
Disposal of operationally exhausted metal working fluids (MWF) through a biological route is an attractive option, since it is effective with relatively low energy demands. However, it is enormously challenging since these fluids are chemically complex, including the addition of toxic biocides which are added specifically to retard bio-deterioration whilst the fluids are operational. Nano-sized elemental iron represents a new generation of environmental remediation technologies. Laboratory scale batch studies were performed to test the degradation ability of a semi-synthetic metalworking fluid (MWF) wastewater (which was found to be resistant to initial bacterial treatment in specifically established bioreactors) by employing a novel hybrid approach. The approach was to combine the synergistic effects of nano zerovalent iron (nZVI) induced oxidation, followed by biodegradation, specifically for the remediation of recalcitrant components of MWF effluent. Addition of nZVI particles to oxygenated wastewater resulted in oxidation of organic contaminants present. Our studies confirmed 78% reduction in chemical oxygen demand (COD) by nZVI oxidation at pH 3.0 and 67% reduction in neutral pH (7.5), and 85% concurrent reduction in toxicity. Importantly, this low toxicity made the nZVI treated effluent more amenable for a second stage biological oxidation step. An overall COD reduction of 95.5% was achieved by the novel combined treatment described, demonstrating that nZVI oxidation can be exploited for enhancing the biodegradability of a recalcitrant wastewater in treatment processes. (C) 2012 Elsevier Ltd. All rights reserved.