WANG Qingyun1,2, ZHANG Guoping1, MA Chao1,2, MAO Kuan1,2, CHEN Jingjing3, LIU Fengjuan3
（1. State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081;
2. University of Chinese Academy of Sciences, Beijing 100049, China；
3. School of Geography and Resources, Guizhou Education University, 550018）
Abstract: In the reducing environments like lakes and marine sediments, FeS is an important carrier of heavy metals. Phosphate may have an important influence on the adsorption behavior of heavy metals on FeS during the eutrophication process. In this paper, through batch experiments with different pH and phosphate concentration, combined with X-ray diffractometer (XRD) and field emission transmission electron microscope-energy spectrometer (TEM-EDS) solid analysis methods, the adsorption process of Sb(Ⅲ) on FeS under phosphate conditions was studied. The results show that under acidic and neutral conditions, the Fe(Ⅱ) released by the dissolution of FeS will reacts with phosphate to form ferrous phosphate precipitation, and this process will promote the dissolution of FeS, release more H2S(aq)/HS- that combine with Sb(Ⅲ) to form Sb2S3 precipitation, and promote the adsorption of Sb(Ⅲ) in the solution at the same time. However, under alkaline conditions, phosphate will compete with Sb(Ⅲ) for adsorption sites on the surface of FeS, accordingly it will inhibit the removal of Sb(Ⅲ) from the solution.
Key words: iron sulfide; trivalent antimony; phosphate; adsorption
EARTH AND ENVIRONMENT Vol.50, No.6, Tot No.350, 2022, Page 916
