研究报告

  • 侯素珍,田浩然,黄超,王平,曾峤婧,彭惠琳,刘素琳,李安.氨基改性生物炭负载纳米零价铁去除水中Cr(VI)[J].环境科学学报,2020,40(11):3931-3938

  • 氨基改性生物炭负载纳米零价铁去除水中Cr(VI)
  • Removal of Cr(VI) from aqueous solution by amino-modified biochar supported nano zero-valent iron
  • 基金项目:国家自然科学基金项目(No.51809293);国家重点研发计划项目(No.2016YFD0800805-4);湖南省自然科学基金项目(No.2019JJ50989);中国博士后基金面上资助项目(No.2018M633004);湖南省教育厅优秀青年基金项目(No.19B588);中南林业科技大学大学生创新创业训练计划项目(No.2019129)
  • 作者
  • 单位
  • 侯素珍
  • 中南林业科技大学环境科学与工程学院, 长沙 410004
  • 田浩然
  • 中南林业科技大学环境科学与工程学院, 长沙 410004
  • 黄超
  • 1. 中南林业科技大学环境科学与工程学院, 长沙 410004;2. 稻米品质安全控制湖南省工程实验室, 长沙 410004
  • 王平
  • 1. 中南林业科技大学环境科学与工程学院, 长沙 410004;2. 稻米品质安全控制湖南省工程实验室, 长沙 410004
  • 曾峤婧
  • 1. 中南林业科技大学环境科学与工程学院, 长沙 410004;2. 稻米品质安全控制湖南省工程实验室, 长沙 410004
  • 彭惠琳
  • 中南林业科技大学环境科学与工程学院, 长沙 410004
  • 刘素琳
  • 中南林业科技大学环境科学与工程学院, 长沙 410004
  • 李安
  • 中南林业科技大学环境科学与工程学院, 长沙 410004
  • 摘要:以聚乙烯亚胺(PEI)为功能单体,玉米秸秆生物炭为载体,制备了氨基改性生物炭负载型纳米零价铁(nZVI@PEI-HBC),并利用扫描电镜(SEM)、红外光谱(FTIR)和X射线光电子能谱(XPS)等手段对材料进行了表征,分析了溶液pH、温度、材料投加量等因素对其去除Cr(VI)的影响及其去除机理.结果表明:在投加量为0.5 g·L-1,温度为20℃,pH值为5,Cr(VI)初始浓度为20 mg·L-1条件下,各材料对Cr(VI)的去除率大小为nZVI@PEI-HBC > nZVI > PEI-HBC > HBC.SEM显示nZVI颗粒较均匀地分散在生物炭表面,FTIR分析表明PEI改性后材料表面增加了氨基等重金属配位基团,这可能是nZVI@PEI-HBC去除Cr(VI)效果更好的原因.影响因素研究表明,材料具有较好稳定性,老化28 d后其Cr(VI)去除性能变化不大;酸性环境、升温、增大材料投加量均有利于nZVI@PEI-HBC对Cr(VI)的去除.机理研究发现,水中溶解氧加速了nZVI的腐蚀和Fe(II)的释放,促进Cr(VI)还原为Cr(III),然后通过共沉淀作用和氨基等基团的吸附作用被去除.
  • Abstract:Amino-modified biochar supported nano zero-valent iron (nZVI@PEI-HBC) was prepared using polyethyleneimine (PEI) as the functional monomer and corn stalk derived biochar as the support material, and was characterized by scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). The effects of solution pH, temperature, and dosage on Cr(VI) removal as well as its mechanism were explored. The results showed that the removal rate of Cr(VI) was in the order of nZVI@PEI-HBC > nZVI > PEI-HBC > HBC under the conditions of dosage 0.5 g·L-1, pH 5 and 20 ℃. SEM images showed that nZVI particles were evenly dispersed on biochar, and FTIR analysis results showed that functional groups for metal complexation such as amino group appeared on the surface of biochar after PEI modification, which contributed to a better Cr(VI) removal performance of nZVI@PEI-HBC. Research on influencing factors showed that the Cr(VI) removal performance of the material was stable and did not change obviously after 28 days of aging, but was enhanced under low pH, high temperature or high dosage. Further mechanism study found that the dissolved oxygen in the water accelerated the corrosion of nZVI and the release of Fe(II), promoted the reduction of Cr(VI) to Cr(III), which then could be removed by co-precipitation and adsorption through amino and other groups.

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