title: Competitive sorption of heavy metals by water hyacinth roots.
abstract: Heavy metal pollution is a global issue severely constraining aquaculture practices, not only deteriorating the aquatic environment but also threatening the aquaculture production. One promising solution is adopting aquaponics systems where a synergy can be established between aquaculture and aquatic plants for metal sorption, but the interactions of multiple metals in such aquatic plants are poorly understood. In this study, we investigated the absorption behaviors of Cu(II) and Cd(II) in water by water hyacinth roots in both single- and binary-metal systems. Cu(II) and Cd(II) were individually removed by water hyacinth roots at high efficiency, accompanied with release of protons and cations such as Ca2+and Mg2+. However, in a binary-metal arrangement, the Cd(II) sorption was significantly inhibited by Cu(II), and the higher sorption affinity of Cu(II) accounted for its competitive sorption advantage. Ionic exchange was identified as a predominant mechanism of the metal sorption by water hyacinth roots, and the amine and oxygen-containing groups are the main binding sites accounting for metal sorption via chelation or coordination. This study highlights the interactive impacts of different metals during their sorption by water hyacinth roots and elucidates the underlying mechanism of metal competitive sorption, which may provide useful implications for optimization of phytoremediation system and development of more sustainable aquaculture industry.
authors: Advanced Lab for Environmental Research & Technology, USTC-CityU, Suzhou, 215123, China; CAS Key Laboratory of Urban Pollutant Conversion, Department of Chemistry, University of Science & Technology of China, Hefei, 230026, China; Department of Biology and Chemistry, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong.
authors: Jia-Chuan
authors: JC
authors: Zheng
authors: Advanced Lab for Environmental Research & Technology, USTC-CityU, Suzhou, 215123, China; CAS Key Laboratory of Urban Pollutant Conversion, Department of Chemistry, University of Science & Technology of China, Hefei, 230026, China.
authors: Hou-Qi
authors: HQ
authors: Liu
authors: Advanced Lab for Environmental Research & Technology, USTC-CityU, Suzhou, 215123, China; CAS Key Laboratory of Urban Pollutant Conversion, Department of Chemistry, University of Science & Technology of China, Hefei, 230026, China; Department of Biology and Chemistry, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong.
authors: Hui-Min
authors: HM
authors: Feng
authors: Advanced Lab for Environmental Research & Technology, USTC-CityU, Suzhou, 215123, China; CAS Key Laboratory of Urban Pollutant Conversion, Department of Chemistry, University of Science & Technology of China, Hefei, 230026, China. Electronic address: wwli@ustc.edu.cn.
authors: Wen-Wei
authors: WW
authors: Li
authors: Advanced Lab for Environmental Research & Technology, USTC-CityU, Suzhou, 215123, China; Department of Biology and Chemistry, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong.
authors: Michael Hon-Wah
authors: MH
authors: Lam
authors: Advanced Lab for Environmental Research & Technology, USTC-CityU, Suzhou, 215123, China; Department of Biology and Chemistry, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong.
authors: Paul Kwan-Sing
authors: PK
authors: Lam
authors: Advanced Lab for Environmental Research & Technology, USTC-CityU, Suzhou, 215123, China; CAS Key Laboratory of Urban Pollutant Conversion, Department of Chemistry, University of Science & Technology of China, Hefei, 230026, China. Electronic address: hqyu@ustc.edu.cn.
authors: Han-Qing
authors: HQ
authors: Yu
mesh_terms: D001673:Biodegradation, Environmental; D002104:Cadmium / Q000378:metabolism; D003300:Copper / Q000378:metabolism; D031806:Eichhornia / Q000378:metabolism*; D007474:Ion Exchange; D019216:Metals, Heavy / Q000378:metabolism*; D018517:Plant Roots / Q000378:metabolism*; D014867:Water / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000378:metabolism*
chemical_list: D019216:Metals, Heavy; D014874:Water Pollutants, Chemical; D002104:Cadmium; D014867:Water; D003300:Copper
keywords: Aquaculture; Binary-metal system; Competitive sorption; Heavy metal; Ionic exchange; Water hyacinth roots