化学学报 ›› 2017, Vol. 75 ›› Issue (6): 629-636.DOI: 10.6023/A17010018 上一篇    下一篇

所属专题: 铁环境化学

研究论文

天然有机质在生物炭负载纳米镍铁降解十溴联苯醚过程中的影响作用机理辨识

易云强a,b,c, 吴娟a,b,c, 方战强a,b,c   

  1. a 华南师范大学 化学与环境学院 广州 510006;
    b 广东省水环境生态治理与修复工程技术研究中心 广州 510006;
    c 广东高校城市水环境生态治理与修复工程技术研究中心 广州 510006
  • 收稿日期:2017-02-14 出版日期:2017-06-15 发布日期:2017-04-01
  • 通讯作者: 方战强 E-mail:sunmoon124@163.com;zhqfang@scnu.edu.cn
  • 基金资助:

    项目受NSFC-广东联合基金(No.U1401235)资助.

Identification Influence Mechanism of Humic Acid in the Degradation of Decabromodiphenyl Ether by the BC@Ni/Fe Nanoparticles

Yi Yunqianga,b,c, Wu Juana,b,c, Fang Zhanqianga,b,c   

  1. a School of Chemistry and Environment, South China Normal University, Guangzhou 510006;
    b Guangdong Technology Research Centre for Ecological Management and Remediation of Water System, Guangzhou 510006;
    c Guangdong Technology Research Centre for Ecological Management and Remediation of Urban Water System, Guangzhou 510006
  • Received:2017-02-14 Online:2017-06-15 Published:2017-04-01
  • Contact: 10.6023/A17010018 E-mail:sunmoon124@163.com;zhqfang@scnu.edu.cn
  • Supported by:

    Project supported by Joint Foundation of NSFC-Guangdong Province (Grant No. U1401235).

天然有机质(NOM)对纳米铁基材料去除污染物过程中的影响作用机理仍存争议.本工作选取腐殖酸(HA)作为NOM的代表物,研究了HA对生物炭负载纳米镍铁(BC@Ni/Fe)降解十溴联苯醚(BDE209)的动力学影响,结果表明HA对BC@Ni/Fe降解BDE209产生抑制作用,且随着HA浓度的升高,抑制作用越显著.通过HA与BC@Ni/Fe相互作用实验发现,HA能够快速地被BC@Ni/Fe吸附;通过HA对BC@Ni/Fe的Zeta电位和沉降影响实验发现,随着HA浓度的升高可有效提高BC@Ni/Fe的稳定性以及表面电荷,这表明HA不是通过影响BC@Ni/Fe颗粒的性能对BC@Ni/Fe去除BDE209产生抑制作用的.BC@Ni/Fe的腐蚀能力随着HA浓度的升高而降低,这与HA对BC@Ni/Fe去除BDE209反应活性影响成正相关关系.HA中具有电子传递作用的典型醌类化合物2-羟基-1,4-萘醌(Lawsone)和蒽醌-2,6-磺酸钠(AQDS),在反应过程中并没有起到电子传递作用促进反应进行,反而对BC@Ni/Fe去除BDE209起抑制作用.结合BDE209和HA之间的竞争吸附实验发现,HA抑制BC@Ni/Fe反应活性的主导原因是HA优先于BDE209被BC@Ni/Fe吸附,HA包覆于BC@Ni/Fe颗粒表面占据了活性位点,阻碍BC@Ni/Fe与H2O的接触,减少了Fe0的腐蚀,从而抑制了BC@Ni/Fe对BDE209的降解.

关键词: 天然有机质, 纳米零价铁, 生物炭负载纳米镍铁, 十溴联苯醚, 影响机制

The influence mechanism of natural organic matter (NOM) on the removal of contaminant by iron-based nanomaterials remains controversial. In this study, the effect of humic acid (representing NOM) on the degradation of decabromodiphenyl ether (BDE209) by biochar supported Ni/Fe nanoparticles (BC@Ni/Fe) were investigated, which indicated that the removal of BDE209 by BC@Ni/Fe was inhibited in the presence of HA, and with the increase of HA concentration, the inhibitory effect showed more significant. The interaction between HA and BC@Ni/Fe shown that HA was quickly adsorbed on the BC@Ni/Fe. The results of the Zeta potential and sedimentation experiment of BC@Ni/Fe showed that the stability and surface charge of BC@Ni/Fe were effectively improved with the increase of HA concentration, indicating that the inhibitory effect of HA in the debromination of BDE209 by BC@Ni/Fe was not through inhibiting the performance of nanoparticles by HA. The corrosion capacity of BC@Ni/Fe decreased with the increase of HA, which did positively correlate with the effect of HA on the reactivity of BC@Ni/Fe in the removal of BDE209. Additionally, those typical quinone compounds in HA (lawsone and AQDS), which have the electron transfer function, did not serve as an electron transfer medium to directly participating in the reaction process, on the contrary, those compounds did adversely effect on the removal of BDE209. In the coexisting system of HA and BDE209, the equilibrium adsorption capacity of HA on BC@Ni/Fe was 4.75 mg/g. Conversely, the adsorption quantities of BDE209 on BC@Ni/Fe in the absence of HA was 0.31 mg/g, which was about 1.3 times higher than that of in the presence of HA (the adsorption quantities of BDE209 was 0.23 mg/g). Moreover, in the coexistent system of HA and BDE209, the kinetic rate constants for the adsorption of HA was 0.1854 min-1, which was approximately 45 times greater than that of BDE209 (0.0041 min-1). It was shown from the analyzed results that the adsorption rate of HA on BC@Ni/Fe was much greater than that of BDE209. Therefore, that is to say, HA could be preferentially adsorbed onto the surface of BC@Ni/Fe. The adsorbed HA coated on the surface of BC@Ni/Fe occupied the active sites, which hindered the nanoparticles to contact with H2O, reduced the corrosion of Fe0, thus inhibited the removal of BDE209.

Key words: natural organic matter, nanoscale zero valent iron, BC@Ni/Fe, decabromodiphenyl ether, influence mechanism