碳酸盐岩对Fe2+生物氧化及铁矿物合成的影响

利用从高硫煤矸石堆场浸出液中培养驯化获得的氧化亚铁硫杆菌（Acidithiobacillus ferrooxidans，A.f），通过静态实验，探讨添加不同量的碳酸盐岩对酸性硫酸盐体系中Fe²⁺生物氧化速率及次生铁矿物合成的影响.结果表明：添加10 g和30 g碳酸盐岩不会对体系中pH、氧化还原电位（ORP）和Fe²⁺生物氧化速率产生明显影响，但总铁（TFe）的去除率可从37%分别提高到55%和62%，矿物生成量也从8.17 g·L^-1分别增加到12.03 g·L^-1和13.69 g·L^-1；同时，体系中合成的次生铁矿物相与不加碳酸盐岩时无明显变化，主要为黄铁矾和施氏矿物的混合物.随着碳酸盐岩添加量增至50、70和90 g时，体系pH快速上升，Fe²⁺生物氧化速率受到抑制，并产生大量结晶程度较好的硫酸钙，形成的铁矿物主要为纤铁矿或针铁矿.而适量的碳酸盐岩添加可使体系中产生Ca²⁺和Mg²⁺，从而影响次生铁矿物的合成.因此，在以碳酸盐岩为反应介质的酸性矿山废水处理工艺设计中，可通过添加A.f菌并控制碳酸盐岩投加量，强化系统中Fe²⁺生物氧化及次生矿物的合成，从而进一步提高反应系统对TFe的去除效果.

The influence of carbonate rock on Fe2+ biological oxidation and iron mineral synthesis

In this study, Acidithiobacillus ferrooxidans (A.f) was incubated and domesticated from the leaching solution of high-sulfur coal gangue yard. Through static experiments, the effects of adding different amounts of carbonate rocks on the biological oxidation rate of Fe²⁺ and the synthesis of secondary iron minerals in sulfate-rich acidic environment were discussed. The results showed that the addition of 10 g and 30 g carbonate rocks did not have a significant effect on pH, ORP and Fe²⁺ biological oxidation rate, but the removal rate of TFe increased from 37% to 55% and 62% respectively, and the mineral production also increased from 8.17 g·L^-1 to 12.03 g·L^-1 and 13.69 g·L^-1, respectively. Meanwhile, the secondary iron mineral phase synthesized in the system had no obvious change compared with that without carbonate rocks, and it was mainly a mixture of schwertmannite and jarosite minerals. With the addition of carbonate rocks to 50 g, 70 g and 90 g, the pH in the system increased rapidly, the biological oxidation rate of Fe²⁺ was inhibited, and a large amount of calcium sulfate with good crystallinity was produced. The iron minerals are mainly lepidocrocite and goethite. The addition of an appropriate amount of carbonate rocks could produce Ca²⁺ and Mg²⁺ in the system, thus affecting the synthesis of secondary iron minerals. Therefore, when using carbonate rocks as a reaction medium to treat acid coal mine wastewater, adding A.f. bacteria and controlling the dosage of carbonate rock could strengthen the biological oxidation of Fe²⁺ and the synthesis of secondary minerals in the system, further improve the removal effect of TFe in the reaction system.