Enhanced effect and mechanism of nano Fe-Ca bimetallic oxide modified substrate on Cu(II) and Ni(II) removal in constructed wetland

Xiaoyan Wang; Wenyue Wang; Wenpeng Wang; Liu Dong; Tianyu Zhai; Zijing Gao; Kang Wang; Wenshu Wang; Sen Wang; Fanlong Kong

doi:10.1016/j.jhazmat.2023.131689

Enhanced effect and mechanism of nano Fe-Ca bimetallic oxide modified substrate on Cu(II) and Ni(II) removal in constructed wetland

J Hazard Mater. 2023 Aug 15:456:131689. doi: 10.1016/j.jhazmat.2023.131689. Epub 2023 May 24.

Authors

Affiliations

¹ College of Environmental Science and Engineering, Qingdao University, Qingdao 266071, China.
² College of Environmental Science and Engineering, Qingdao University, Qingdao 266071, China. Electronic address: wangsen@qdu.edu.cn.
³ College of Environmental Science and Engineering, Qingdao University, Qingdao 266071, China. Electronic address: kongfanlong@qdu.edu.cn.

PMID: 37245372
DOI: 10.1016/j.jhazmat.2023.131689

Abstract

In this study, Fe₂O₃ nanoparticles (Fe₂O₃ NPs) and CaO NPs were loaded on the zeolite sphere carrier to create nano Fe-Ca bimetallic oxide (Fe-Ca-NBMO) modified substrate, which was introduced into constructed wetland (CW) to remove Cu(II) and Ni(II) via constructing "substrate-microorganism" system. Adsorption experiments showed that the equilibrium adsorption capacities of Fe-Ca-NBMO modified substrate for Cu(II) and Ni(II) were respectively 706.48 and 410.59 mg/kg at an initial concentration of 20 mg/L, 2.45 and 2.39 times of gravel. The Cu(II) and Ni(II) removal efficiencies in CW with Fe-Ca-NBMO modified substrate respectively reached 99.7% and 99.9% at an influent concentration of 100 mg/L, significantly higher than those in gravel-based CW (47.0% and 34.3%). Fe-Ca-NBMO modified substrate could promote Cu(II) and Ni(II) removal by increasing electrostatic adsorption, chemical precipitation, as well as the abundances of resistant microorganisms (Geobacter, Desulfuromonas, Zoogloea, Dechloromonas, and Desulfobacter) and functional genes (copA, cusABC, ABC.CD.P, gshB, and exbB). This study provided an effective method to enhance Cu(II) and Ni(II) removal of electroplating wastewater by CW with Fe-Ca-NBMO modified substrate.

Keywords: Electroplating wastewater; Fe-Ca-NBMO modified substrate; Functional genes; Microbial community structure.