铅锌尾砂矿耐性微生物的筛选及其吸附机理研究

发布时间：2018-01-09 02:17

本文关键词：铅锌尾砂矿耐性微生物的筛选及其吸附机理研究　出处：《中南林业科技大学》2015年硕士论文　论文类型：学位论文

【摘要】：针对湖南资兴铅锌矿污染问题,筛选本土耐性菌株用作生物修复。本论文研究了一株耐性真菌活性菌株及失活菌体的吸附特性及吸附机理,为其在重金属治理的应用提供条件。论文取得的主要研究结果如下：(1)经过连续3次富集培养后,从湖南资兴铅锌矿区的尾砂矿矿渣中分离得到真菌19株,放线菌5株,通过比较其耐性及去除铅锌效果,筛选出耐性菌株J3作为供试菌株。根据形态特征和系统发育分析,J3初步鉴定为虫生轮枝菌。(2)菌量是影响J3失活菌体吸附Pb2+的极显著因素,pH值、吸附时间是影响吸附Pb2+的显著因素；Zn2+浓度、pH值分别是影响其吸附锌离子的极显著和显著因素。最佳条件下,失活菌体对Pb2+去除率为72.6%,Zn2+的去除率为23.8%。失活菌体Pb2+吸附推测为膜扩散和颗粒内扩散共同作用,Zn2+吸附速率则由膜扩散控制。二级动力学方程可为生物吸附反应器的设计提供依据。(3)重金属浓度是影响活性菌株去除Pb2+、Zn2+的显著因素,其他三个因素影响不显著,说明了活性菌株去除效果的稳定性。在最佳条件下,J3活性菌株对Pb2+的去除率达到92.2%,Zn2+的去除率率为87.7%。活性菌株吸附过程中吸附速率受重金属浓度影响,Zn2+吸附主要为颗粒内扩散作用。(4)本研究采用多种方法对活性菌株吸附机理进行分析。首先,SEM结果说明：添加重金属后J3菌球表面更为致密,内部疏松中空；随着铅锌离子浓度增加,菌丝逐渐塌陷聚集,变为扁平状,菌丝和菌球的形变过程可能对重金属去除起重要作用。其次,红外光谱分析结果表明,官能团-NH、-CH2、-OH、C=O和C-O等参与了Pb2+、Zn2+吸附过程,其中-OH和C=O是优先吸附位点。第三,活性菌株在生长前后pH值发生了变化,J3在生长过程中产生了碱性物质,高浓度下菌丝表面产生大量沉淀。最后结合前实验结果并解吸实验结果,表明较低浓度下(75mg/L)J3 Pb2+去除主要为胞内积累,较高浓度下(75-300 mg/L)主要为胞外吸附作用；锌离子去除机制则主要为胞内吸附。
[Abstract]:In order to solve the pollution problem of Zixing lead-zinc mine in Hunan Province, a native resistant strain was selected for bioremediation. In this paper, the adsorption characteristics and adsorption mechanism of a resistant fungal active strain and inactivated bacteria were studied. The main results obtained in this paper are as follows: 1) after three successive enrichment and culture. 19 strains of fungi and 5 strains of actinomycetes were isolated from the tail-sand slag of Zixing lead-zinc mine in Hunan Province. The tolerance and the effect of removing lead and zinc were compared. The resistant strain J3 was selected as the tested strain. According to morphological characteristics and phylogenetic analysis, J3 was preliminarily identified as rotifer. 2) the quantity of J3 inactivated bacteria was the most significant factor affecting the adsorption of Pb2 by J3 inactivated bacteria. The pH value and adsorption time were the significant factors affecting the adsorption of Pb2. The pH value of Zn2 was the most significant and significant factor affecting the adsorption of zinc ions. Under the optimum conditions, the removal rate of Pb2 by inactivated bacteria was 72.6%. The removal rate of Zn2 was 23.8.The Pb2 adsorption of inactivated bacteria was supposed to be the interaction of membrane diffusion and intragranular diffusion. The adsorption rate of Zn2 was controlled by membrane diffusion. The second-order kinetic equation could provide the basis for the design of biosorption reactor. The significant factors of Zn2, the other three factors, showed the stability of the removal effect of the active strain. Under the best conditions, the removal rate of Pb2 of the J3 active strain reached 92.2%. The removal rate of Zn2 was 87.7%. The adsorption rate of active strain was affected by the concentration of heavy metal. Zn2 adsorption is mainly intragranular diffusion. 4) in this study, the adsorption mechanism of active strains was analyzed by various methods. First of all. The results of SEM showed that the surface of J3 microspheres was denser and the interior was loose and hollow after the addition of heavy metals. With the concentration of lead and zinc ions increasing, the mycelium gradually collapses and aggregates and becomes flat. The deformation process of hyphae and microspheres may play an important role in the removal of heavy metals. Secondly, the infrared spectrum analysis results show that. Functional groups such as -NH ~ (2 +) -H _ (2) C _ (2) C _ (2) O and C-O are involved in the adsorption process of Pb2 ~ (2 +) Zn _ (2), among which -OH and C _ (10) O are the preferred sites for adsorption. The pH value of the active strain changed before and after growth, and J3 produced alkaline substances during the growth process, and a large amount of precipitation occurred on the surface of the mycelium at high concentration. Finally, the results of pre-test and desorption were combined. The results showed that the removal of 75 mg 路L ~ (-1) J _ (3) Pb2 was mainly intracellular accumulation at lower concentration, and the extracellular adsorption at higher concentration (75 ~ 300 mg / L). The removal mechanism of zinc ion is mainly intracellular adsorption.
【学位授予单位】：中南林业科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X172;X753

【参考文献】