腐殖酸改性及其对镉的吸附特性

对腐殖酸改性前后表面理化性质的改变及其对水中镉离子的吸附性能进行了研究。结果表明,改性后腐殖酸比表面积和孔结构均有明显改善,吸附能力增强。吸附实验结果表明:随着pH的增大,改性后腐殖酸对镉离子的吸附量增加,在pH约为6时,吸附效率达到最大并趋于稳定; 改性后腐殖酸对镉离子的吸附最高可达20 mg/g,吸附等温线用Langmuir模型拟合最佳。吸附再生实验表明,改性腐殖酸吸附剂具有不易损失、易再生的特点,可以循环使用。

Study on the modification of humic acid and its adsorption to cadmium

Variation of the surface physical-chemical properties of humic acid(HA)before and after modification and their adsorption properties for Cd²⁺ in water were investigated. The adsorption behaviors of modified HA on Cd²⁺ were also examined under various experimental conditions. It was observed that the surface textural properties of modified HA were improved, which was in favour of adsorption. The fundamental adsorption experiments revealed that the modified HA was more efficient for Cd²⁺ removal when initial solution pH was about 6. The theoretical maximal adsorption capacity is about 20 mg/g. Which is based on the simulation results from the isothermal equilibrium study. The adsorption equilibrium behaviors were in accordance with Langmuir model. Furthermore, the modified HA adsorbent could be easily regenerated and reused with almost no loss of adsorption capacity, which would be satisfactory for practical applications.