松木基水热炭热改性材料对水相Pb^2+的吸附作用

Adsorption Performance of Pinewood-Based Pyro-Hydrothermalchar Modified Material for Lead Ions Removal in Water

针对水环境中重金属Pb^2+的微污染问题,利用制备的松木基水热炭材料进一步高温炭化热处理进行改性,制备得到具有优化结构和性能的水热炭材料HC。HC对水相Pb^2+的吸附作用研究表明,相应的HC900材料对Pb^2+具有优良的吸附性能,对Pb^2+的最大吸附容量达到463.2 mg/g,相比于未经热处理的水热炭,HTC的吸附容量提高超过8倍。对吸附材料的构效关系分析发现,松木基水热炭材料经高温热处理后,材料表面形成了更为丰富的含氧官能团和发达的孔隙结构,从而大大提高了吸附能力,吸附机理包括表面络合、离子交换和π电子配位。吸附Pb^2+过程符合准二级动力学模型,等温线吸附试验数据符合Freundlich模型,且多层吸附是该吸附过程的主要方式。进一步研究表明,该HC900材料对实际水样中低浓度的Pb^2+也有高效的去除能力,表明该材料对水环境中微量铅污染的处理具有良好的应用前景。

In view of micro-pollution of heavy metal lead ions in water environment,prepared pinewood-based hydrochar material was further modified by high-temperature carbonization heat treatment to obtain pinewood-based pyro-hydrothermalchar modified materials HC with optimized structure and properties.The adsorption studies of HC materials to lead ions showed that corresponding HC900 material had an excellent adsorption ability for lead ions,and the maximum adsorption capacity for lead ions reached 463.2 mg/g,which was eight times higher than that of HTC material without heat treatment.The structure-activity relationship analysis of HC materials indicated that after pinewood-based hydrochar material was treated at high temperature,richer oxygen-containing functional groups and a developed pore structure were formed on the surface of the material,thereby greatly improving the adsorption capacity.Adsorption mechanisms included surface complexation,ion exchange andπelectron coordination.The adsorption process to lead ions could be well simulated by pseudo-second-order kinetic model.The isotherm adsorption experimental data could be well described by Freundlich model,and multilayer adsorption was the main way in the adsorption process.Further research showed that HC900 material could also efficiently remove low-concentration lead ions in actual water samples,indicating that synthesized material had good application prospects for the treatment of trace lead pollution in water environment.