Fu Yuran, Zhang Ruixue, Wang Neng, Wu Pan, Zhang Yahui, An Li, Zhang Yuhao
Resource and Environmental Engineering College, Guizhou University, Guiyang 550025, China.
Key Laboratory of Karst Georesources and Environment, Ministry of Education, Guiyang 550025, China.
Toxics. 2023 Feb 27;11(3):224. doi: 10.3390/toxics11030224.
The effect of pH is a key factor in biomineralization mediated by to promote the transformation of Fe into secondary iron minerals. This study aimed to investigate the effects of initial pH and carbonate rock dosage on bio-oxidation and secondary iron mineral synthesis. Variations in pH and the concentrations of Ca, Fe, and total Fe (TFe) in the growth medium of were examined in the laboratory to determine how they affect the bio-oxidation process and secondary iron mineral synthesis. The results showed that in systems with an initial pH of 1.8, 2.3, and 2.8, the optimum dosages of carbonate rock were 30, 10, and 10 g, respectively, which significantly improved the removal rate of TFe and the amount of sediments. At an initial pH of 1.8 and a carbonate rock dosage of 30 g, the final removal rate of TFe reached 67.37%, which was 28.03% higher than that of the system without the addition of carbonate rock, and 36.9 g·L of sediments were generated, which was higher than that of the system without the addition of carbonate rock (6.6 g·L). Meanwhile, the number of sediments generated by adding carbonate rock were significantly higher than those without the addition of carbonate rock. The secondary minerals were characterized by a progressive transition from low crystalline assemblages composed of calcium sulfate and subordinated jarosite, to well crystal-line assemblages composed of jarosite, calcium sulfate, and goethite. These results have important implications for comprehensively understanding the dosage of carbonate rock in mineral formation under different pH conditions. The findings help reveal the growth of secondary minerals during the treatment of AMD using carbonate rocks under low-pH conditions, which offers valuable information for combining the carbonate rocks with secondary minerals to treat AMD.
pH值的影响是由……介导的生物矿化过程中促进铁转化为次生铁矿物的关键因素。本研究旨在探究初始pH值和碳酸盐岩用量对生物氧化及次生铁矿物合成的影响。在实验室中检测了……生长培养基中pH值以及Ca、Fe和总铁（TFe）浓度的变化，以确定它们如何影响生物氧化过程和次生铁矿物合成。结果表明，在初始pH值为1.8、2.3和2.8的体系中，碳酸盐岩的最佳用量分别为30、10和10 g，这显著提高了TFe的去除率和沉积物量。在初始pH值为1.8且碳酸盐岩用量为30 g时，TFe的最终去除率达到67.37%，比未添加碳酸盐岩的体系高出28.03%，生成了36.9 g·L的沉积物，高于未添加碳酸盐岩的体系（6.6 g·L）。同时，添加碳酸盐岩产生的沉积物数量显著高于未添加碳酸盐岩的情况。次生矿物的特征是从由硫酸钙和次要的黄钾铁矾组成的低结晶组合，逐渐过渡到由黄钾铁矾、硫酸钙和针铁矿组成的良好结晶组合。这些结果对于全面理解不同pH条件下矿物形成过程中碳酸盐岩的用量具有重要意义。这些发现有助于揭示在低pH条件下使用碳酸盐岩处理酸性矿山废水过程中次生矿物的生长情况，为将碳酸盐岩与次生矿物结合用于处理酸性矿山废水提供了有价值的信息。
