Cyanobacterial blooms increase the release of vanadium through iron reduction and dissolved organic matter complexation in the sediment of eutrophic lakes

• Published in: Water research (Oxford) Vol. 243; p. 120377
• Main Authors: Wang, Yan, Zhu, Dongdong, Li, Cai, You, Xiaohui, Zhou, Li, Zhang, Lan, Xiao, Jing, Chen, Musong, Ding, Shiming, Hang, Xiaoshuai
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.09.2023
• Subjects: acute exposure; ecotoxicology; Eutrophication; geochemistry; High-resolution sampling; humans; lakes; Netherlands; organic matter; pollution; Redox conditions; risk; sediments; Sediment–water interface; solubility; summer; toxicity; vanadium; Vanadium mobility; water; winter; Netherlands; High-resolution sampling; Redox conditions; Vanadium mobility; Sediment–water interface; Eutrophication
• ISSN: 0043-1354; 1879-2448; 1879-2448
• DOI: 10.1016/j.watres.2023.120377

•The redox geochemistry and mobility of V in a eutrophic lake sediments are overall discussed.•The high mobility of v was caused by the reduction of Fe(hydr)oxides and DOM complexation associated with the algal bloom.•The solubility of v is controlled by the transition between V(Ⅴ) and V(Ⅳ) and the complex with DOM.•Spatiotemporal distribution of soluble v are obtained insitu using high resolution methods of HR-Peeper and DGT. Vanadium (V), a hazardous environmental contaminant, can be highly toxic to aquatic or even human life. Nonetheless, knowledge of its redox geochemistry and mobility in sediments, especially those of eutrophic lakes, remains limited. In this study, we combined in situ high-resolution sampling and laboratory simulation experiments for monitoring soluble and labile V to reveal the mobilization mechanism of V in the sediment of Lake Taihu. The results showed that the concentration of soluble V (1.18–5.22 µg L−1) exceeded the long-term ecotoxicology limitation proposed by the government of the Netherlands. The highest value appeared in summer (July to September), with an average concentration of 3.87 µg L−1, which exceeded the short-term exposure limit. The remobilization of V in summer was caused by the combined effect of the reduction of Fe(hydr)oxides and dissolved organic matter (DOM) complexation, which accelerated the release of associated Fe-bound V and increased the solubility of DOM-V. Additionally, V showed high mobility in winter, owing to the species of V(Ⅲ)/V(Ⅳ) being oxidized to V(Ⅴ) with higher solubility. It is noteworthy that the elevated remobilization of V in sediments increases the risk of V release from sediments, which poses the threat of water V pollution in Lake Taihu. [Display omitted]