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硫酸盐还原菌(SRB)分解硫酸盐矿物对C、S、Fe、Sr、Ba等元素的循环起着重要制约作用,二者相互作用机制的阐明具有重要的矿物学、地球化学及地质微生物学意义。通过设计厌氧实验,本文探讨了SRB与硬石膏的作用过程及机理。结果表明,较之无菌体系,SRB体系中氧化还原电位(EORP)显著降低;可挥发性硫(AVS)与蛋白质浓度则不断增大;硬石膏中总溶出硫含量增加;硬石膏表面SRB粘附位置出现明显溶蚀现象。分析表明SRB通过两种机制促进硬石膏分解:SRB还原代谢消耗溶解态SO42-,降低SO42-浓度,进而促使硬石膏持续溶解;SRB粘附于硬石膏表面,其自身及代谢产物通过络合硬石膏中的Ca加速矿物分解,此种机制在前人的研究中被普遍忽略,而通过此机制SRB亦可促进难溶硫酸盐(天青石、重晶石等)及铁氧化物的溶解,进而制约相关元素的地球化学行为。
Sulfate-reducing bacteria (SRB) decomposition of sulfate minerals plays an important role in controlling the cycling of elements such as C, S, Fe, Sr and Ba. The elucidation of their interaction mechanism has important mineralogical, geochemical and geological microbiology significance. Through the design of anaerobic experiments, the paper explores the action process and mechanism of SRB and anhydrite. The results showed that compared with the sterile system, the redox potential (EORP) of SRB system decreased significantly, while the volatile sulfur (AVS) and protein concentration increased continuously. The total dissolved sulfur content of anhydrite increased. Attached location obvious erosion phenomenon. The analysis shows that SRB promotes the decomposition of anhydrite through two mechanisms: the SRB reduces the SO42- concentration and reduces the concentration of SO42-, thereby promoting the continuous dissolution of the anhydrite; the SRB adheres to the surface of the anhydrite, and itself and the metabolites pass through the complexation hard The Ca in gypsum accelerates the decomposition of minerals. This mechanism has been generally ignored in previous studies. With this mechanism, SRB can also promote the dissolution of insoluble sulfates (celestite, barite, etc.) and iron oxides Restrict the geochemical behavior of related elements.