王超,宋卫锋,杨佐毅,钟永铿,孙梦格,白晓燕.工业固废基地聚合物的制备及其吸附Pb(Ⅱ)的性能[J].环境科学学报,2021,41(7):2700-2711
工业固废基地聚合物的制备及其吸附Pb(Ⅱ)的性能
- Synthesis of industrial wastes-based geopolymer and its adsorption capacity for Pb(Ⅱ)
- 基金项目：广东省自然科学基金（No.2021A1515010558）
- 王超
- 广东工业大学环境科学与工程学院, 广州 510006
- 宋卫锋
- 广东工业大学环境科学与工程学院, 广州 510006
- 杨佐毅
- 广东工业大学环境科学与工程学院, 广州 510006
- 钟永铿
- 广东工业大学环境科学与工程学院, 广州 510006
- 孙梦格
- 广东工业大学环境科学与工程学院, 广州 510006
- 白晓燕
- 广东工业大学环境科学与工程学院, 广州 510006
- 摘要：地聚合物（GP）具有三维立体网状结构，对重金属有良好的吸附性能，通常由偏高岭土等制得，但利用工业固体废物制备GP及探究其吸附性能的研究还相对较少.因此，本研究以煤矸石掺杂赤泥作为原料制备GP，采用酸溶法探究在不同制备条件下GP各组分的变化及其与重金属吸附性能的关系，同时评估其浸出毒性.结果表明，在未加外源硅的情况下，GP对水溶液中Pb（Ⅱ）的吸附性能会随着凝胶含量的增加而提升，而外源硅则可以促进原料中Al2O3的溶出，改变凝胶的性质，进而提升其吸附性能.同时，相较于NaOH和NaOH+NaAlO2激活剂，采用NaOH+Na2SiO3激活剂制备得到的GP对重金属的吸附性能更优异，理论最大吸附量达到137.7 mg·g-1.GP对水溶液中Pb（Ⅱ）的吸附以化学吸附为主，符合二级动力学规律，吸附过程也很好地符合Langmuir等温方程.另外，GP可以有效地固化原材料中的重金属，减少其浸出.XRD等分析表明，煤矸石掺杂赤泥作为原料可以制备具有良好重金属吸附性能的GP.本研究可为工业固废的综合利用提供新的途径和方法，为以废治废提供理论指导.
- Abstract：Geopolymer(GP) possesses a three-dimensional network structure and shows great adsorption properties for heavy metals. Geopolymer are usually made from metakaolin, however, synthesis of geopolymers using industrial solid wastes has never been reported. In this study, geopolymers were prepared by using coal gangue and red mud and their adsorption capacity for Pb(Ⅱ) in aqueous solution was investigated. The variation of geopolymer components under different preparation conditions was analyzed by hydrochloric acid solution method and leaching toxicity was also evaluated. The results showed that the variation of gel content in geopolymer showed a fair linear correlation with its adsorption capacity for Pb(Ⅱ) in the absence of external silica source. The external silica source could promote the dissolution of Al2O3 in the raw material which changed the properties of the gel and thus improved the adsorption performance of geopolymers. Moreover, compared with different alkaline activators, the geopolymer prepared by NaOH+Na2SiO3 activator displayed the best adsorption performance for heavy metals and the theoretical maximum adsorption capacity was shown reached up to 137.7 mg·g-1. The adsorption of Pb(Ⅱ) in aqueous solution by geopolymers were mainly through chemical adsorption, which conformed to the second-order kinetic, and the adsorption processes were also fitted well to the Langmuir isotherm model. Simultaneously, geopolymers effectively solidified heavy metals in raw materials and reduced the leaching toxicity. XRD and other characterizations have shown that the geopolymer prepared from coal gangue and red mud exhibited great adsorption performance for heavy metals. This research provided an new approache to reutilizate industrial solid wastes and the theoretical guidance for waste treatment.
