DONG Lisha1 , ZHANG Yuqin1 ,WEI Shihong1,GUO Xingqiang 1 ,ZHU Jian1,2 , SHANGGUAN Lixin3
(1. College of Resources and Environmental Engineering, Key Laboratory of Karst Georesources and Environment, Ministry of Education ,Guizhou University, Guiyang 550025, China;
2. Guizhou Karst Environmental Ecosystems Observation and Research Station, Ministry of Education, Guiyang 550025, China;
3. North Alabama International College of Engineering and Technology, Guizhou University, Guizhou University, Guiyang 550025, China)
Abstract: To investigate the colloidal formation mechanism of natural organic matter (NOM) and antimony ( Sb) in acid mine drainage (AMD) , fulvic acid ( FA) was chosen to represent NOM to react with Sb( III) . Thereafter, X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy ( FT-IR) were taken to characterize the FA-Sb colloids formed under different initial C( FA) /Sb ratios. The experimental results reveal that FA significantly promoted the formation of FA-Sb particles and colloids. The higher the initial molar C( FA) / Sb was, the more FA-Sb colloids with the lower was the Zeta potential and smaller particle size. The formation of FA-Sb colloids is facilitated by the presence of oxygen-containing functional groups such as hydroxyl groups in FA and stabilized by the negative charge of FA. A small amount of Sb( III) in AMD might be oxidized by reactive oxygen species, produced by FA in the presence of light, and the oxidation rate of Sb( III) gradually increased with the increasing C( FA) / Sb ratio (0-2 000) . The results of this study highlight the interaction between FA and Sb in AMD from the colloid geochemical perspective, and provide deeper insights into the geochemical behavior of Sb in AMD.
Key words: acid mine drainage; fulvic acid; antimony; formation of colloids
EARTH AND ENVIRONMENT： Vol. 51, No. 5, Tot No.355 2023
