Norcardia Amarae菌吸附Hg^(2+)的研究

Biosorption of Hg^(2+) By Norcardia Amarae

研究了Norcardiaamarae菌体对水相中重金属离子Hg2+的吸附特性,并测定了菌体的ξ电位 pH曲线及其等电点数据·结果表明,Norcardiaamarae菌体对Hg2+具有良好的吸附效果;该吸附是一个快速过程,在2min以内就达到吸附平衡;在较宽的pH值范围内(4 0～12 0),Norcardiaamarae菌体对Hg2+去除率均达96%以上,在pH>12 0时溶液开始产生Hg(OH)2,此时Hg2+去除率反映的不仅是生物吸附的效果,而且是沉淀与吸附共同作用的结果;吸附温度为23℃时,Hg2+去除率最高;用该菌吸附质量浓度为400mg/L的Hg2+溶液,Hg2+的去除率可达97%·经实验测定,Norcardiaamarae菌体的等电点为pH=2 1,静电吸附是该吸附过程的影响因素之一·

The biosorption of Hg2+ by the biomass of Norcardia amarae was studied, with the ξpotentialpH curve and isoeletric point of the biomass particulates measured. The experimental results show that the biomass of Norcardia amarae has a favorable biosorption effect on Hg2+. As a quick adsorption process, an equilibrium of the process can be got just in 2 minutes. The biomass of Norcardia amarae can remove over 96% Hg2+ in a broad range of pH value from 40 to 120, and begin to produce Hg(OH)2 when pH value>120-at that moment the removing rate of Hg2+ is not only due to biosorption but to a combining effect of precipitation with biosorption. The removing rate is found highest at the adsorption temperature 23?℃. The removing rate of Hg2+ can be up to 97% if using the biomass to adsorb Hg2+ solution of concentration 400?mg/L. It is indicated that the isothermal point of the biomass is at pH=21, and the electrostatic adsorption is one of the influencing factors on the biosorption process.