桉树叶绿色合成纳米铁修复地下水铬污染

地下水Cr(VI)污染修复是当前急需解决的水环境污染问题之一，纳米铁用于修复地下水Cr(VI)污染具有潜在优势，然而存在成本高、易团聚沉降氧化等瓶颈问题。利用植物提取液作为还原剂与铁盐作用绿色合成多功能纳米铁，能够有效降低纳米铁合成成本，提高纳米铁的抗氧化性、分散性和吸附性，使得大规模原位修复成为可能。然而，植物提取液合成纳米铁的机理和绿色纳米铁还原Cr(VI)的影响机制尚不清楚。桉树是世界上三大速生丰产树种之一，桉树叶含有多酚、黄酮、有机酸等多种活性物质。本项目提出采用桉树叶提取液合成纳米铁，分析桉树叶提取液有效成分，揭示绿色合成纳米铁的机理；探讨绿色合成纳米铁还原Cr(VI)的影响机制；以及地下水中各类共存物质（如有机物、无机离子等）对绿色合成纳米铁去除Cr(VI)效率的影响。项目研究成果将为绿色合成纳米铁用于修复地下水Cr(VI)污染提供技术支持。

Remediation of Cr(VI) from the contaminated groundwater is a great challenge. Significant potential has been demostrated for the application of nanoscale iron particles (nZVI) for groundwater remeidation. However, since nZVI tend to aggregate and to oxidize, and to produce nZVI by chemical method with a high cost, nZVI is limitd in its field application. Green synthesis of nZVI using plant extracts and iron ions has low cost and environmental friendly. Green nZVI also has good oxidation resistance and dispersibility. However, it is still unclear for the formation of nZVI by green synthesis and the reduction of Cr(VI) in ground water using green nZVI. Eucalyptus is one of three fast growing trees in the world, and eucalyptus leaves contain polyphenols, flavonoids, organic acids and other active substances. Therefore, eucalyptus leaf extracts can be acted as both reducing and stabilizing agents in the green synthesis of nZVI. For these reasons, the primary objective of the proposal is to 1) Understanding the green synthesis mechanism of nZVI using Eucalyptus leaf extracts; 2) explore the reduction mechanism of Cr(VI) by green synthesized nZVI; 3) investigate the factors such as organic matter and inorganic ions in groundwater, which could impacte the reduction of Cr(VI). Results of this study will provide fundamental knwledge on the application of green synthesis of nZVI used to remove Cr(VI) in ground water.