工业水处理 ›› 2023, Vol. 43 ›› Issue (3): 87-95. doi: 10.19965/j.cnki.iwt.2022-0337

• 试验研究 • 上一篇    下一篇

改性纳米零价铁去除地下水硝酸盐的研究

张笑天1(), 张阳阳1, 祖波1(), 张云霞1, 陈克军2   

  1. 1.重庆交通大学国家内河航道整治工程技术研究中心, 重庆 400074
    2.招商局生态环保科技有限公司, 重庆 400067
  • 收稿日期:2022-12-16 出版日期:2023-03-20 发布日期:2023-03-21
  • 通讯作者: 祖波 E-mail:466716221@qq.com;zubo@cqjtu.edu.cn
  • 作者简介:张笑天(1996— ),硕士研究生。E-mail:466716221@qq.com
    祖波,教授。E-mail:zubo@cqjtu.edu.cn
  • 基金资助:
    重庆市自然科学基金面上项目(cstc2021jcyj-msxmX0328);重庆市自然科学基金博士后科学基金项目(cstc2021jcyj-bshX0231)

Research on nitrate removal from groundwater by modified nano-zerovalent iron

Xiaotian ZHANG1(), Yangyang ZHANG1, Bo ZU1(), Yunxia ZHANG1, Kejun CHEN2   

  1. 1.National Engineering Research Center for Inland Waterway Regulation,Chongqing Jiaotong University,Chongqing 400074,China
    2.China Merchants Ecological Environmental Protection Technology Co. ,Ltd. ,Chongqing 400067,China
  • Received:2022-12-16 Online:2023-03-20 Published:2023-03-21
  • Contact: Bo ZU E-mail:466716221@qq.com;zubo@cqjtu.edu.cn

摘要:

采用提纯凹凸棒土(ATP)负载纳米零价铁(nZVI)制备得到改性材料ATP-nZVI,将其用于对地下水硝酸盐的去除研究。通过静水实验考察了溶液中共存阴离子和反应温度对ATP-nZVI去除NO3--N的影响,通过模拟可渗透反应墙(PRB)考察了溶液初始pH、初始NO3--N浓度、材料装填方式、流速对ATP-nZVI去除NO3--N的影响,并通过更换PRB装填材料将ATP-nZVI与石英砂、ATP、铁粉、nZVI等材料对NO3--N的去除效果进行了比较。结果表明:共存阴离子对ATP-nZVI去除NO3--N具有抑制作用,其抑制作用的顺序为PO43->CO32->SO42->Cl-;ATP-nZVI对NO3--N去除率与反应温度呈正相关,但总体来讲其受温度变化的影响并不明显;同一pH条件下,ATP-nZVI对NO3--N去除率随着硝酸盐溶液质量浓度的增大而减小;对于相同质量浓度的硝酸盐溶液,相比在中性和碱性环境,其在酸性条件下NO3--N去除率较高;ATP-nZVI的装填层数越多,对NO3--N的去除率越高,长效性也越好;流速越大,ATP-nZVI对于NO3--N的去除率越小,效果越差;PRB柱填充不同材料时的去除效果为ATP-nZVI>nZVI>铁粉(200目,即74 μm)>ATP>石英砂,ATP-nZVI作为PRB的填充材料时,系统对NO3--N的去除稳定性与去除率得到有效提升,具有良好的实用性。机制研究表明,ATP-nZVI对NO3--N的去除主要归因于nZVI的还原作用,而ATP对于nZVI的负载则加强了这种还原作用。

关键词: 凹凸棒土, 纳米零价铁, 反应渗透墙(PRB), 硝酸盐

Abstract:

Modified material ATP-nZVI was prepared by purifying attapulgite(ATP) loaded with nano-zerovalent iron(nZVI) and was used to remove nitrate from groundwater. The effects of anions in the solution and reaction temperature on the nitrate removal by ATP-nZVI were investigated by hydrostatic experiments. The effects of initial pH,initial nitrate concentration,material loading method and flow rate of the solution on the nitrate removal by ATP-nZVI were investigated by simulated permeable reaction wall(PRB). The nitrate removal effect of ATP-nZVI was compared with that of quartz sand,ATP,iron powder and nZVI by replacing the PRB loading materials. The results showed that the coexisting anions inhibited the removal of NO3--N by ATP-nZVI,and the inhibition sequence was PO43->CO32->SO42->Cl-. The removal rate of NO3--N by ATP-nZVI was positively correlated with reaction temperature,but it was not significantly affected. At the same pH,the removal rate of NO3--N by ATP-nZVI decreased with the increase of the mass concentration of nitrate solution. For nitrate solution with the same mass concentration,the removal rate of NO3--N was higher under acidic conditions than in neutral and alkaline environments. The higher the number of ATP-nZVI filling layers,the higher the nitrate removal rate and the better the long-term effectiveness. The higher the flow rate,the smaller the removal rate of nitrate by ATP-nZVI,and the worse the effect. When PRB column was filled with different materials,the removal effect was ATP-nZVI>nZVI>iron powder(200 mesh,74 μm)>ATP>quartz sand. When ATP-nZVI was used as the filling material of PRB,the removal stability and removal rate of NO3--N in the system were effectively improved,which had good practicability. The mechanism study showed that the removal of nitrate by ATP-nZVI was mainly attributed to the reductive action of nZVI,and the load of ATP on nZVI strengthened the reductive action.

Key words: attapulgites, nano-zerovalent iron, reaction penetration wall(PRB), nitrate

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