论文部分内容阅读
以铅锌矿渣盆栽试验中长势较好的耐性植物夹竹桃(Nerium indicum)的根际土壤为材料,进行耐铅锌优势菌株的分离鉴定,探讨影响铅锌吸附的因素及其吸附机理。结果表明:(1)从土样中分离筛选出3株耐铅锌菌株(B1、B4、B14),3株菌均能在Pb2+、Zn2+浓度为600 mg·L-1的牛肉膏蛋白胨培养基上生长,经形态和分子生物学鉴定分别为蜡样芽孢杆菌(Bacillus cereus)或炭疽杆菌(Bacillus anthracis)、解硫胺素硫胺素芽孢杆菌(Aneurinibacillus aneurinilyticus)和藤黄微球菌(Micrococcus luteus)。(2)对影响菌株吸附铅、锌的p H、吸附时间、初始菌量3个因素进行分析,发现菌株B1在p H为5.0、吸附时间为50 min、初始菌量为0.06 g时,对Pb2+、Zn2+的去除率分别可达84.22%和70.66%。菌株B4在p H为6.0、吸附时间为50 min、初始菌量为0.18 g时,对Pb2+、Zn2+的去除率分别可达72.63%和54.17%。菌株B14在p H为4.0、吸附时间为60 min、初始菌量为0.10 g时对Pb2+、Zn2+的吸附率分别为77.56%和50.63%。(3)扫描电镜观察和红外光谱分析显示:3株菌对Pb2+、Zn2+的吸附主要是细胞表面的吸附,还存在一定的内部吸收;羟基(O-H)、胺基(N-H)、烷基、酰胺基(CONH-)是吸附、络合或螯合金属离子或原子的主要活性基团,重金属与菌株表面的活性基团结合反应是其吸附Pb2+、Zn2+的主要作用机制。
The rhizosphere soils of better-growing Nerium indicum, a growing lead-zinc slag pot experiment, were used for isolation and identification of the dominant strains of lead and zinc, and the factors affecting the adsorption of lead and zinc and their adsorption mechanism were discussed. The results showed as follows: (1) Three strains of lead tolerant zinc (B1, B4, B14) were isolated and screened from soil samples. All of the three strains could be cultured in beef extract peptone medium with Pb2 + and Zn2 + concentrations of 600 mg · L-1 Were identified by morphology and molecular biology as Bacillus cereus or Bacillus anthracis, Aneurinibacillus aneurinilyticus and Micrococcus luteus, . (2) The factors affecting the adsorption of lead, zinc p H, adsorption time, the initial bacteria amount of three factors were analyzed and found that strain B1 in the pH of 5.0, the adsorption time of 50 min, the initial volume of 0.06 g, The removal rates of Pb2 + and Zn2 + were 84.22% and 70.66% respectively. Strain B4 had a Pb2 + and Zn2 + removal efficiencies of 72.63% and 54.17%, respectively, at a pH 6.0, an adsorption time of 50 min and an initial bacterial count of 0.18 g. Strain B14 had an adsorption rate of 77.56% and 50.63% for Pb2 + and Zn2 +, respectively, at a pH 4.0, an adsorption time of 60 min and an initial bacterial count of 0.10 g. (3) The results of scanning electron microscopy and infrared spectroscopy showed that the adsorption of Pb2 + and Zn2 + by these three strains was mainly on the cell surface and some internal absorption existed. The hydroxyl groups (OH), amine groups (NH), alkyl groups, amides (CONH-) is the main active group adsorbing, complexing or sequestering metal ions or atoms. The binding reaction between heavy metals and the active groups on the surface of the bacteria is the main mechanism of adsorption of Pb 2+ and Zn 2+.