鸡血藤药渣对废水中Cu2+的吸附行为

采用废弃中药渣鸡血藤（Spatholobus suberectus Dunn.，SSD）为生物吸附剂对废水中铜离子（Cu²⁺）进行吸附，探讨吸附性能和吸附机理，为废水中Cu²⁺的去除和中药渣的资源化利用提供参考依据。通过吸附性能试验探讨了吸附剂剂量、pH值、初始离子浓度、温度、时间和共存阳离子对SSD吸附Cu²⁺的影响，根据吸附前后SSD的形貌特征，探讨其对Cu²⁺的吸附机理。结果表明，SSD对Cu²⁺的吸附速率较大，在30 min时吸附达到平衡。增加吸附剂剂量、pH值和吸附时间均会促进SSD对Cu²⁺的吸附，共存阳离子会在一定程度上抑制Cu²⁺的吸附。Sips等温模型能更好地描述不同温度下SSD对Cu²⁺的吸附过程，吸附特征是Langmuir和Freundlich模型的结合。SSD对Cu²⁺的吸附符合准二级动力学方程，表明化学吸附是反应的限速步骤。SSD对Cu²⁺的吸附机理包括离子交换、络合和静电吸引。研究表明，废弃中药渣鸡血藤可用于废水中Cu²⁺的去除。

Adsorption of Cu2+ from wastewater by a residue of production of a Chinese medicine from Spatholobus suberectus Dunn.

The aim of this study is to examine the efficacy of a byproduct of production of a Chinese medicine from ^{Spatholobus suberectus} Dunn.(SSD) as an adsorbent to remove Cu²⁺ from polluted water. These studies of adsorption capacity and adsorption mechanism offer insights into a new means for Cu²⁺ removal from contaminated water, and enhance resource utilization related to production of a Chinese medicine. Variables affecting Cu²⁺ removal efficiency, including SSD dose, pH value, initial ion concentration, temperature, time, and coexisting cations, were investigated by adsorption performance tests. The results showed the adsorption rate of SSD for Cu²⁺ was fast, and adsorption reached equilibrium after 30 min. The Cu²⁺ adsorption mechanism was addressed by examining SSD morphological characteristics before and after adsorption. Cu²⁺ adsorption by SSD was improved with increasing SSD dose, pH value, and time, while coexisting cations inhibited Cu²⁺ removal to a certain degree. The Cu²⁺ adsorption data fit the Sips model well, suggesting that Cu²⁺ adsorption on SSD occurs by a combined Freundlich-Langmuir model. The Cu²⁺ removal mechanism includes ion exchange with Ca²⁺ and Mg²⁺, chelating with SSD surface functional groups, and electrostatic attraction between cationic Cu²⁺ and negative charges on SSD. In conclusion, SSD can be used for Cu²⁺ removal from wastewater.