State Key Laboratory of Petroleum Pollution Control, Beijing Key Lab of Oil & Gas Pollution Control, China University of Petroleum-Beijing, Beijing, 102249, China.
Institute of Environmental Research, Shandong University, Jinan, 250100, China.
Chemosphere. 2020 Nov;258:127289. doi: 10.1016/j.chemosphere.2020.127289. Epub 2020 Jun 6.
Anammox-based processes and microbial consortia have drawn extensive attention for their use in high-efficiency wastewater treatment technologies. Metals substantially affect the activity of anammox consortia and the quality of wastewater treatment plant effluent. Here, we explored the role of anammox consortia in terms of metals complexation in both single and multi-metal systems. Adsorption edges of single metal cations indicate that the adsorption preference was in the order: Pb(II) > Cd(II) > Cr(VI). A competitive effect was observed in multi-metal cations systems, with Pb(II) being preferably adsorbed and the degree of adsorption somewhat reduced in the presence of either Cd(II) or Cr(VI), while Cd(II) and Cr(VI) were easily exchanged and substituted by other metals. Fourier transform infrared (FTIR) and X-ray photoelectron spectroscopy (XPS) further suggest that the adsorption of Pb(II) and Cd(II) are as inner-sphere ion-exchange mechanisms, while Cr(VI) adsorption is mainly by outer-sphere complexation. Density functional theory (DFT) calculations highlight that Cd(II) and Pb(II) have different binding sites compared to Cr(VI), and the order of binding energy (E) of three metal cations were Pb(II) > Cd(II) > Cr(VI). These calculations support the adsorption data in that Pb forms more stable complexes with anammox bacterial surface ligands. Surface complexation modelling (SCM) further predicted both the sorption of single metal cations and competitive adsorption of the three metals to anammox consortia, the exception being Cd at higher loadings. The results of this study highlight the potential role of anammox consortia in removing metal cations from wastewater in treatment systems.
基于厌氧氨氧化的工艺和微生物群落因其在高效废水处理技术中的应用而受到广泛关注。金属会显著影响厌氧氨氧化菌群的活性和废水处理厂出水的质量。在这里，我们研究了厌氧氨氧化菌群在单一和多金属体系中金属络合方面的作用。单一金属阳离子的吸附边缘表明，吸附偏好顺序为：Pb(II) > Cd(II) > Cr(VI)。在多金属阳离子体系中观察到竞争效应，Pb(II)优先被吸附，而在存在 Cd(II)或 Cr(VI)的情况下，吸附程度略有降低，而 Cd(II)和 Cr(VI)则容易被其他金属交换和取代。傅里叶变换红外（FTIR）和 X 射线光电子能谱（XPS）进一步表明，Pb(II)和 Cd(II)的吸附是内球离子交换机制，而 Cr(VI)的吸附主要是通过外球络合。密度泛函理论（DFT）计算突出表明，与 Cr(VI)相比，Cd(II)和 Pb(II)具有不同的结合位点，三种金属阳离子的结合能（E）顺序为 Pb(II) > Cd(II) > Cr(VI)。这些计算结果支持了吸附数据，表明 Pb 与厌氧氨氧化细菌表面配体形成更稳定的配合物。表面络合模型（SCM）进一步预测了单一金属阳离子的吸附和三种金属对厌氧氨氧化菌群的竞争吸附，除了 Cd 在较高负荷下的情况。这项研究的结果强调了厌氧氨氧化菌群在处理系统中从废水中去除金属阳离子的潜力。
