微生物抑制黄铁矿氧化产酸的实验研究

发布时间：2018-04-19 06:43

本文选题：矿山酸性废水 + 矿山原位修复　；参考：《北京有色金属研究总院》2015年硕士论文

【摘要】：矿山酸性废水以其酸度高,量大,持续性强,重金属离子种类多且浓度高等特点严重污染了矿山周边环境,对生态环境影响恶劣,严重威胁到人类的生活健康。矿山酸性废水问题受到广泛关注。目前治理矿山酸性废水主要依靠末端治理,但不是长久之计,建立在抑制黄铁矿氧化基础上的矿山酸性废水的源头控制逐步受到重视。本论文中研究了一种抑制黄铁矿氧化的矿山原位修复思路的效果。利用以硫酸盐还原菌和铁还原菌为主的修复细菌与含有有机碳源乳酸钠和酵母提取物的培养基构成抑制体系,用该体系模拟抑制矿山酸性废水的产生,取得了良好的效果。研究了蛋白胨,酵母提取物和乳酸钠作为抑制体系中碳源的效果,结果表明乳酸钠能够更好的维持硫酸盐还原菌的生长和还原硫酸盐的作用,确立了以乳酸钠为主要有机碳源与OK无机盐组成培养基的抑制体系。研究了抑制体系中的有机碳源对铁氧化细菌的影响,结果表明,1.0g/L以上的乳酸钠对铁氧化细菌的生长和氧化二价铁的能力有明显的抑制效果,酵母提取物对铁氧化细菌无明显影响。据此对抑制体系中的乳酸钠浓度进行优化,由最初的6.0g/L降低至1.0g/L,同时添加0.1g/L的酵母提取物以维持铁还原菌的生长。研究了优化后的抑制体系对黄铁矿氧化产酸的抑制效果。结果表明,黄铁矿在抑制体系中的氧化受到阻止,抑制体系的pH值维持在中性(6.62),氧化还原电位维持在低于黄铁矿氧化的临界电位600 mV,同时总铁离子含量和硫酸根浓度急剧下降,抑制效果明显。修复细菌在阻止黄铁矿氧化起到决定性作用,乳酸钠的存在减缓了黄铁矿的氧化产酸循环,并维持硫酸盐还原菌的生长。抑制体系中的黄铁矿表面矿相转变研究表明,修复细菌能够吸附黄铁矿表面并生成附着物,附着物的主要成分为有机物与铁硫等元素的复合物,包含蓝铁矿和磁黄铁矿,说明抑制体系能够有效固化液相中的铁,有助于抑制黄铁矿氧化。微生物群落结构与动态演变表明,所用硫酸盐还原菌适宜在抑制体系中生长,与其伴生的兼性厌氧菌起到消耗氧气营造厌氧环境的作用,铁氧化细菌受到抑制。硫酸盐还原菌和铁氧化细菌的荧光定量PCR分析表明,硫酸盐还原菌能够在抑制体系中稳定生长,细菌浓度增加；而铁氧化细菌在抑制体系中持续受到抑制,不能发挥铁氧化二价铁离子的能力。上述结果表明,所构建的抑制体系有较好的稳定性和可持续性,在源头控制矿山酸性废水以及矿山的原位修复领域中有良好的前景。
[Abstract]:Mine acid wastewater has the characteristics of high acidity, large quantity, strong persistence, many kinds of heavy metal ions and high concentration, which seriously pollutes the surrounding environment of mine, affects the ecological environment badly, and seriously threatens the health of human life.The problem of mine acid wastewater has been paid more and more attention.At present, the treatment of mine acid wastewater mainly depends on the end treatment, but it is not a long-term solution. The source control of mine acid wastewater based on the inhibition of pyrite oxidation has been paid more and more attention.In this paper, the effect of an in-situ restoration method for pyrite oxidation is studied.The repairable bacteria mainly from sulfate reducing bacteria and iron reducing bacteria and the medium containing organic carbon source sodium lactate and yeast extract were used to form the inhibition system. The system was used to simulate the inhibition of the production of mine acid wastewater, and good results were obtained.The effects of peptone, yeast extract and sodium lactate as carbon sources in the inhibition system were studied. The results showed that sodium lactate could better maintain the growth of sulfate reducing bacteria and the role of reducing sulfate.The inhibition system of the medium composed of sodium lactate as the main organic carbon source and OK inorganic salt was established.The effects of organic carbon sources on ferric oxidizing bacteria were studied. The results showed that sodium lactate above 1.0 g / L had obvious inhibitory effect on the growth of ferric oxidizing bacteria and the ability of oxidizing iron divalent.Yeast extract had no obvious effect on iron oxidizing bacteria.The concentration of sodium lactate in the inhibition system was optimized from the initial 6.0g/L to 1.0 g / L, and the yeast extract of 0.1g/L was added to maintain the growth of ferric reducing bacteria.The inhibition effect of the optimized inhibition system on pyrite oxidation and acid production was studied.The results showed that the oxidation of pyrite in the inhibition system was prevented, the pH value of the inhibition system was maintained at 6.62 渭 m, the redox potential was maintained at 600mV below the critical potential of pyrite oxidation, and the total iron ion content and sulfate concentration decreased sharply.The inhibitory effect was obvious.Repair bacteria played a decisive role in preventing pyrite oxidation. The presence of sodium lactate slowed down the oxidation of pyrite and maintained the growth of sulfate reducing bacteria.Studies on the ore-phase transformation of pyrite surface in the inhibition system show that the remediation bacteria can adsorb the pyrite surface and form appendages, the main components of which are the complexes of organic compounds with iron and sulfur elements, including blue ore and pyrrhotite, and pyrrhotite.The results show that the inhibition system can effectively solidify iron in liquid phase and is helpful to inhibit the oxidation of pyrite.The microbial community structure and dynamic evolution showed that the sulfate reducing bacteria were suitable for growth in the inhibition system. The facultative anaerobes associated with them had the function of consuming oxygen to create an anaerobic environment and the ferric oxidizing bacteria were inhibited.Fluorescence quantitative PCR analysis of sulfate reducing bacteria and iron oxidizing bacteria showed that sulfate reducing bacteria could grow stably and the concentration of bacteria increased in the inhibition system, while iron oxidizing bacteria were continuously inhibited in the inhibition system.The ability of iron to oxidize divalent iron ions cannot be brought into play.The results show that the system has good stability and sustainability, and has a good prospect in the field of source control of mine acid wastewater and in situ restoration of mine.
【学位授予单位】：北京有色金属研究总院
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X172;X751

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