【摘要】 为解决微生物对重金属吸附的应用问题,筛选了一种嗜镍菌,研究了最优条件下嗜镍菌对镍离子的特效吸附。表明:Langmuir方程能很好地描述嗜镍菌对Ni2+吸附的热力学过程,在最佳条件下嗜镍菌对镍离子吸附2h,饱和吸附量可达92.59mg/g;嗜镍菌对Ni2+的吸附动力学过程符合二级反应模型,由吸附率随时间的变化曲线可见:镍离子为25mg/L,吸附时间2h,吸附即趋于平衡,吸附率最高可达97.7%,对超标50倍的含镍废水,一次处理已接近镍的排放标准;该菌对含镍废水中Ni2+的吸附有特效性。热力学模型与红外光谱和原子力显微镜测定同时说明嗜镍菌对Ni2+的作用以表面为主,其主要吸附位点是菌体胞外聚合物的蛋白质、多糖的羟基和氨基;这对该菌作为工程菌的回用有宜。更多还原

【Abstract】 In order to solve the application of adsorption of heavy metal by microorganism,nickel-resistant strain was screened.The specific adsorption of nickel by the strain was investigated under the optimum conditions.Studies illustrated that the thermodynamic adsorption of Ni2+ by nickel-resistant strain could be described by Langmuir model.Under optimal conditions,the saturated adsorption capacity is up to 92.59mg/g as nickel-resistant strain absorbs Ni2+ to two hours.The adsorption kinetics of Ni2+ by nickel-resistant strain fitted the second-order kinetic model.Based on the curve of adsorption rate versus time,the following information canfitured out: When the concentration of Ni2+ is 25mg/L and the adsorption time is two hours,the adsorption tends to reach the balance and the rate of adsorption can reach up to 97.7%.The nickel-containing wastewater that exceeds the national standard of 50 times is close to the emission standard through primary treatment.The bacteria bears specific adsorption capability for nickel in wastewater.The thermodynamic model,IR spectra and AFM detection showed that the adsorption of Ni2+ by nickel-resistant strain mainly occurred on the surface of the thallus.The main adsorption sites were the h·roxyl and amidogen groups from the protein and polysaccharide on the exocellular polymer of strain.It is conducive to recycle the bacteria during its application as engineering bacteria.更多还原