Shao Yan, Chen Zhiliang, Zhang Zhonglei, Pang Jun, Li Yinyin, Zhu Jia, Zhang Gen, Wang Xiaoshu, Chang Ming, Wang Lei
Institute for Thermal Power Engineering, State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou, China.
Wuhan City Environment Protection Engineering Limited Company, Wuhan, China.
Front Chem. 2022 Aug 17;10:971540. doi: 10.3389/fchem.2022.971540. eCollection 2022.
This work investigated the removal of cadmium ions (Cd) by using biochar derived from . The biochars derived from the pyrolysis of roots (BGR), stems (BGS) and leaves (BGL) were characterized and their performance for cadmium adsorption was studied at varying parameters of temperature, time, and alkali (earth) metal concentrations. The maximum adsorption amount at equilibrium of BGR, BGS and BGL was determined experimentally as 8.38 mg/g, 42.12 mg/g, and 30.39 mg/g. Adsorption fitting results revealed that Cd2+ adsorbed on BGR and BGS preferred to be multilayer-covered, and BGL was more likely to have monolayer-covered functions. The kinetic data fitted well to the pseudo-second-order model ( > 0.99), revealing the adsorption process was a spontaneous monolayer chemisorption process. The results of alkaline (earth) metals leaching of biochar revealed that the inherent alkaline (earth) metals in biochar made inhibitory functions on the Cd adsorption behavior by occupying the active sites. And in the process of wastewater treatment, the leaching of alkaline earth metals might enhance the complexation reaction between surface groups and Cd. This study provides a feasible strategy for the resource utilization of abundant hydrophytic plants in waste management.
本研究考察了利用源自……的生物炭去除镉离子（Cd）的效果。对由根（BGR）、茎（BGS）和叶（BGL）热解得到的生物炭进行了表征，并研究了其在不同温度、时间和碱（土）金属浓度参数下对镉的吸附性能。通过实验测定，BGR、BGS和BGL在平衡时的最大吸附量分别为8.38 mg/g、42.12 mg/g和30.39 mg/g。吸附拟合结果表明，吸附在BGR和BGS上的Cd2+更倾向于多层覆盖，而BGL更可能具有单层覆盖功能。动力学数据与准二级模型拟合良好（>0.99），表明吸附过程是一个自发的单层化学吸附过程。生物炭中碱（土）金属的浸出结果表明，生物炭中固有的碱（土）金属通过占据活性位点对Cd的吸附行为产生抑制作用。并且在废水处理过程中，碱土金属的浸出可能会增强表面基团与Cd之间的络合反应。本研究为在废物管理中对丰富的水生植物进行资源利用提供了一种可行的策略。
