基于海藻酸钠—聚丙烯酰胺凝胶包埋技术制备微生物氧化剂的研究

发布时间：2018-06-27 06:35

  本文选题：氧化剂 + 氧化亚铁硫杆菌　； 参考：《南华大学》2015年硕士论文

【摘要】：随着工业生产的发展,矿产资源的需求量不断增加,其开采规模越来越大。深部矿体、低品位矿体、复杂条件矿体已逐渐成为主要的开采加工对象。针对这些开采对象,传统的采选方法难以实现经济高效、安全、环保的生产要求。微生物浸出技术具有弥补传统采选方法的这一缺点,生物氧化剂的制备是微生物浸出技术的关键。本实验以海藻酸钠-聚丙烯酰胺两种混合材料为载体,并加入极易溶于水的聚乙二醇400(PEG)为致孔剂,以Ca Cl2、柠檬酸铝为交联剂,用包埋法固定A.f菌并构建固定床生物反应器以生产Fe3+制备微生物氧化剂。为了制备具有高氧化能力的微生物氧化剂,本实验的主要研究内容如下:(1)通过条件实验,选择出了A.f菌的最佳包埋条件为:海藻酸钠浓度为2.5%,聚丙烯酰胺浓度为0.4%,聚乙二醇400浓度为2%。在此条件下所制得的固定化A.f菌Fe2+的最大氧化速率为2.863g·(L·h)-1。凝胶小球内A.f菌增值比例可达到1.51倍。固定化A.f菌重复使用15d后,依然保持较好的氧化能力。(2)以选择的最佳固定化条件包埋A·f菌制备大量凝胶微球,装入自制的固定床生物反应器内,通过条件实验获得了固定床生物反应器的最佳运行条件为:空气流量为1.4 L·min-1、初始p H值为2.0、反应器外层恒温夹套水温为32℃、初始Fe2+浓度为8.5 g·L-1、稀释率为0.6 h-1。反应器在该条件下连续运行,得到Fe2+的最大氧化速率为2.97 g·L-1·h-1,是游离态A·f菌的3.38倍。反应器开始连续运行15d后,对Fe2+的氧化能力略有降低,通过清洗反应器内沉淀物质后,固定化A·f菌的氧化能力恢复84%,实验表明固定床生物反应器稳定性较好。最终实验通过分析获得固定化A·f菌对Fe2+的一级反应速率常数为k=0.39 h-1。
[Abstract]:With the development of industrial production, the demand for mineral resources is increasing. Deep ore body, low grade ore body and complex ore body have gradually become the main objects of mining and processing. For these mining objects, the traditional mining methods are difficult to meet the requirements of economic, efficient, safe and environmental protection. Microbial leaching technology has the disadvantage of traditional extraction and separation, and the preparation of biological oxidant is the key of microbial leaching technology. In this experiment, sodium alginate and polyacrylamide were used as the carrier, polyethyleneglycol 400 (PEG), which was easily soluble in water, was added as porous agent, and calcium chloride _ 2 and aluminum citrate were used as crosslinking agents. A fixed bed bioreactor was constructed to produce Fe3 to produce microbial oxidant. In order to prepare microbial oxidant with high oxidation ability, the main contents of this experiment are as follows: (1) through conditional experiment, The optimum embedding conditions of A. F bacteria were as follows: sodium alginate concentration was 2.5, polyacrylamide concentration was 0.4, polyethylene glycol 400 concentration was 2. 5%. Under these conditions, the maximum oxidation rate of the immobilized A. f strain Fe2 was 2.863 g (L h) -1. The increment ratio of A. f bacteria in gel pellets can reach 1.51 times. After repeated use for 15 days, the immobilized A. F bacteria still maintained good oxidation ability. (2) A large number of gel microspheres were prepared by embedding A f bacteria under the optimum immobilization conditions, and were placed in a self-made fixed-bed bioreactor. The optimal operating conditions of the fixed bed bioreactor were obtained by the condition experiment: the air flow rate was 1.4 L min -1, the initial pH value was 2.0, the water temperature of the jacket was 32 鈩，

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