Department of Civil and Environmental Engineering, Lehigh University, Bethlehem, PA, 18015, USA.
Environ Sci Pollut Res Int. 2018 Mar;25(9):8620-8635. doi: 10.1007/s11356-017-1122-8. Epub 2018 Jan 9.
The use of carbon soot recovered from diesel particulate filters (DPF) has been investigated as a potential adsorbent for heavy metals including cadmium, chromium, and copper from wastewater. Results were compared with the adsorption performance of powder activated carbon (PAC). The uptake capacity of heavy metals for soot was found to be higher than PAC. And the thermodynamic study result for both soot and PAC indicated the adsorption procedures are exothermic. The adsorption studies were carried out for both single and binary systems. The data are best modeled by the monolayer model and Langmuir isotherm model for single systems. The adsorption mechanisms are more complex for binary systems. The kinetic studies indicated the adsorption happens rapidly within the first 1 h, and the results can be best modeled by pseudo-second-order model. The SEM-EDS analysis revealed the soot possesses higher porosity and surface area. Carboxylic and hydroxyl functional groups are the predominant surface functional group on both soot and PAC as revealed by FTIR and IEP values. The adsorption can be explained by both Van Der Waals force and electrostatic force. Graphical abstract ᅟ.
从柴油机微粒过滤器（DPF）中回收的碳黑已被用作从废水中吸附重金属（包括镉、铬和铜）的潜在吸附剂。研究结果与粉末活性炭（PAC）的吸附性能进行了比较。发现重金属对碳黑的吸附容量高于 PAC。并且，对碳黑和 PAC 的热力学研究结果表明，吸附过程是放热的。对单组分和双组分体系都进行了吸附研究。单组分体系的实验数据最符合单层模型和 Langmuir 等温线模型。对于双组分体系，吸附机制更为复杂。动力学研究表明，吸附在最初的 1 小时内迅速发生，实验结果最符合准二级动力学模型。SEM-EDS 分析表明，碳黑具有更高的孔隙率和表面积。如 FTIR 和 IEP 值所示，碳黑和 PAC 表面的主要官能团为羧酸和羟基。吸附可以用范德华力和静电力来解释。
