废啤酒酵母去除水中重金属镉的作用机理

Mechanism of cadmium removal in aqueous solution by waste beer yeast

利用废啤酒酵母为生物吸附材料处理水溶液中的Cd2+.为了考察废啤酒酵母表面官能团在生物吸附过程中的作用,分别对废啤酒酵母进行甲醇、甲醛化学修饰,使其表面的羧基发生酯化反应、胺基发生甲基化反应.同时对反应前后溶液pH值的变化进行了监测.结果表明,酯化反应后,废啤酒酵母吸附Cd2+的能力降低,证实羧基在Cd2+吸附中起到了重要作用;甲基化反应后,废啤酒酵母吸附Cd2+的能力升高,是因为反应后pH值变化使Cd2+发生无机微沉淀作用而去除.表面官能团以及pH升高引起的沉淀对镉去除起重要作用.

Waste beer yeast was used as an adsorbent for modified separately by methanol and formaldehyde in on the surface of the waste beer yeast in biosorption adsorption was also monitored. Esterification of the biosorption capacity of cadmium, which suggests that the removal of cadmium from water. The biomass was order to study the role played by the functional groups of cadmium. And the change of pH before and after carboxyl groups present in the biomass decreased the carboxylic acid played an important role in biosorption of cadmium. However, formaldehyde-treated biomass increased the biosorption capacity, due to the change of pH after the reaction and subsequent precipitation and removal of Cd2＋ Functional groups and the precipitation caused by pH increase are important for the removal of cadmium by the waste beer yeast.