Pan Siyi, Wu Pingxiao, Sun Leiye, Chen Meiqing, Li Bo, Wang Tianming, Shang Zhongbo, Fang Jiangmin, Zhu Nengwu, Dang Zhi
School of Environment and Energy, South China University of Technology, Guangzhou Higher Education Mega Centre, Guangzhou, 510006, China.
School of Environment and Energy, South China University of Technology, Guangzhou Higher Education Mega Centre, Guangzhou, 510006, China; Guangdong Provincial Key Laboratory of Solid Wastes Pollution Control and Recycling, Guangzhou, 510006, China; Guangdong Engineering and Technology Research Center for Environmental Nanomaterials, Guangzhou, 510006, China; The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, Guangzhou, 510006, China.
Environ Pollut. 2024 Dec 15;363(Pt 1):125061. doi: 10.1016/j.envpol.2024.125061. Epub 2024 Oct 5.
Green rust (GR), as a vital intermediate product during the formation of various iron oxides, exists with organic matters and metals contaminants in natural environments. Understanding the effects of these natural factors on the transformation process of GR into iron oxides and the environmental behaviors of heavy metals and organic matters during process are critical for environmental quality management, but the fundamental identification of the interaction mechanisms between them and GR is still challenging. In this study, the transformation mechanisms of Co-bearing green rust (GR-Co) synthesized by co-precipitation, and the redistribution behaviors of Co(II) in an environment containing oxalic acid (OA) and citric acid (CA) were clarified. The findings indicated that OA promoted the Fe(II) dissolution and the transformation of GR-Co to goethite, while CA decreased the Fe(II) dissolution and the proportion of non-extractable Co. Furthermore, in the presence of CA, the transformation products of GR-Co were ferrihydrite, magnetite, lepidocrocite and goethite instead of only lepidocrocite and goethite. Meanwhile, CA prohibited ferrihydrite from transforming into more highly crystalline iron minerals. The finding of this study improves the understanding of the interaction mechanisms between GR-Co and organic matter, and the environmental geochemical behaviors of Co and organic carbon during the transformation processes in nature.
绿锈（GR）作为各种铁氧化物形成过程中的重要中间产物，在自然环境中与有机物和金属污染物共存。了解这些自然因素对GR转化为铁氧化物过程的影响以及该过程中重金属和有机物的环境行为，对于环境质量管理至关重要，但明确它们与GR之间相互作用机制的基本特征仍具有挑战性。本研究阐明了通过共沉淀法合成的含钴绿锈（GR-Co）的转化机制，以及Co(II)在含有草酸（OA）和柠檬酸（CA）的环境中的重新分布行为。研究结果表明，OA促进了Fe(II)的溶解以及GR-Co向针铁矿的转化，而CA则降低了Fe(II)的溶解和不可萃取Co的比例。此外，在CA存在的情况下，GR-Co的转化产物为水铁矿、磁铁矿、纤铁矿和针铁矿，而非仅为纤铁矿和针铁矿。同时，CA阻止了水铁矿向结晶度更高的铁矿物转化。本研究结果增进了对GR-Co与有机物之间相互作用机制以及自然转化过程中Co和有机碳环境地球化学行为的理解。
