【作者】 贾伟伟；

【导师】 吕早生；

【作者基本信息】 武汉科技大学 ， 化学工艺， 2010， 硕士

【摘要】 本文研究了从湖北某矿的酸性坑水中分离到的嗜酸氧化亚铁硫杆菌(Acidithiobacillus ferrooxidans,At. f)和嗜酸氧化硫硫杆菌(Acidithiobacillus thiooxidans, At. t)混合菌为浸磷菌进行低品位磷矿的浸磷实验。At. f和At. t混合菌浸磷率比同源单一At.f菌提高32%,浸出速度快,且对能源物质的消耗少。亚铁和黄铁矿的加入对At. f和At. t混合菌的浸磷有显著的助浸作用,最佳用量分别为7 g/100 mL和0.5 g/100 mL;适量表面活性剂吐温40、60和80的加入对混合菌浸磷也有一定的促进作用。以初始pH、接种量和矿浆浓度为正交试验因素得出最佳浸磷条件为初始pH =1.5;菌种量为15%;矿浆浓度为15 g/L;浸磷率达51.07%。诱变处理对黄铁矿存在条件下混合菌浸出磷矿粉中的磷的最佳工艺条件为:微波595 W辐射混合菌20 s,浸磷率提高了65%;30 W紫外灯下20 cm照射混合菌3 min,浸磷率提高了67%;超声波400 W处理混合菌工作次数30次(超声时间3 s/次,间歇时间7 s/次),浸磷率提高了一倍;浓度为0.2 mol/L的亚硝酸钠0.6 mL诱变处理20 min,浸磷率提高了17%;超声波400 W处理微波正突变菌工作次数30次,浸磷率提高了一倍;30 W紫外灯下20 cm照射微波正突变菌3 min,浸磷率提高了78%。混合菌在代谢过程分泌了有机酸如苹果酸,柠檬酸,草酸等与硫酸共同参与浸磷。本文从浸磷矿液中分离和纯化出一株浸磷菌LLJQ-1,研究了该菌的形态,生理生化特征,糖、醇利用研究,16S rDNA序列分析以及系统发育树分析,结果表明菌株LLJQ-1为铜绿假单胞菌(Pseudomonas aeruginosa,P. aeruginosa)。本文首次发现LLJQ-1为溶磷微生物。该菌在初始pH= 2.5、接种量10%和矿浆浓度为10 g/L的条件下,浸磷率达83.9%。在pH均为2.5的条件下,利用该菌溶解磷矿粉的浸磷率比稀硫酸直接溶解提高了45%。菌株LLJQ-1在代谢过程中分泌有机酸主要是柠檬酸,苹果酸和酒石酸,其中产生的柠檬酸含量最高,达74.815 mg/L。更多还原

【Abstract】 The mixed bacteria of Acidithiobacillus ferrooxidans ( At.f ) and Acidithiobacillus thiooxidans(At. t), which were for phosphorus leached of low-grade phosphate rock, were isolated from acidic drainage from a mine in Hui Bei Province. Results showed that the mixed bacteria had higher rate of phosphorus leached, which increased 32%, faster leaching rate and lower consumption of energy sources , compared with Acidithiobacillus ferrooxidans. Ferrous and pyrite played a significant role in promoting the leaching of the ore and the optimal dosages were 7 g/100 mL and 0.5 g/100 mL. Appropriate amount of tween 40, 60 and 80 all could promote the interaction between the mixed bacteria and the ore and increase the rate of phosphate leached. The leaching conditions were defined as follows: initial pH was 1.5; inoculum concentration was 15% (v/v); phosphate concentration was 1.5 g per 100 mL;the phosphorus leached was up to 51.07%.The optimal technological parameters of bioleaching soluble phosphorus by mutated mixed bacteria were: radiating with 595 W microwave for 20 s, increased 65%; irradiating with 30 W ultraviolet ray lamp for 3 min, increased 67%; treating with 400 W ultrasound for 30 times(a time: cavitation time 3 s, interval time 7 s), increased one time ; mixing with 0.6 mL of 0.2 mol/L sodium nitrite for 20 min, increased 17%; treating with 400 W ultrasound for 30 times on the positive mutated strains by microwave, increased one time; irradiating with 30 W ultraviolet ray lamp for 3 min on the positive mutated strains by microwave, increased 78%. Organic acids including malic acid, citric acid and oxalic acid, which were released by the mixed bacteria, soluted the rock phosphate together with sulphuric acid.The strain LLJQ-1 was isolated from the low-grade rock phosphate leached Solution. It was characterized by the morphological observation, the physiological and biochemical analysis, the studies of nitrate and alcohol Utilization, 16S rDNA sequencing analysis and the morphological analysis. The result showed that the strain LLJQ-1 was identified as Pseudomonas Aeruginosa. It was the first time to report the strain as the phosphate solubilizing microorganism in this study. In the conditions that initial pH was 2.5, phosphate concentration was 1.0 g per 100 mL and inoculum concentration was 10% (v/v), the phosphorus leached of the strain LLJQ-1 was 83.90%. Under the same condition (pH was 2.5), the phosphorus leached of the strain LLJQ-1 increased 45% compared with the sulfuric acid leaching. The main organic acids which were released by the strain LLJQ-1 were citric acid, malic acid and tartaric acid, and the content of citric acid was up to 74.82 g/L.更多还原