Energy and Environmental Sustainability Solutions for Megacities (E2S2), Campus for Research Excellence and Technological Enterprise (CREATE), Singapore 138602, Singapore; NUS Environmental Research Institute, National University of Singapore, 1 Create Way, Create Tower #15-02, 138602, Singapore.
Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, 117576 Singapore.
Chemosphere. 2023 Jul;329:138524. doi: 10.1016/j.chemosphere.2023.138524. Epub 2023 Apr 3.
As compared to alkali-activated geopolymers with phosphoric acid which may be used in high concentrations resulting in disposal concerns, acid-based geopolymers may have superior properties. A novel green method of converting waste ash to a geopolymer for use in adsorption applications such as water treatment is presented here. We use methanesulfonic acid, a green chemical with high acid strength and biodegradability to form geopolymers from coal and wood fly ashes. The geopolymer is characterized for its physico-chemical properties and tested for heavy metal adsorption. The material specifically adsorbs iron and lead. The geopolymer is coupled to activated carbon forming a composite, which adsorbs silver (precious metal) and manganese (hazardous metal) significantly. The adsorption pattern complies with pseudo-second order kinetics and Langmuir isotherm. Toxicity studies show while activated carbon is highly toxic, the geopolymer and the carbon-geopolymer composite have relatively less toxicity concerns.
与可能需要高浓度磷酸才能激活的碱激发地质聚合物相比，具有强酸性的地质聚合物可能具有更优异的性能。本文提出了一种将废灰转化为地质聚合物以用于水处理等吸附应用的新型绿色方法。我们使用甲烷磺酸，一种具有高酸性和生物降解性的绿色化学品，来从煤和木灰中形成地质聚合物。对地质聚合物的物理化学性质进行了表征，并对其重金属吸附性能进行了测试。该材料特别吸附铁和铅。将地质聚合物与活性炭偶联形成复合材料，可显著吸附银（贵金属）和锰（危险金属）。吸附模式符合准二级动力学和朗缪尔等温线。毒性研究表明，虽然活性炭具有高毒性，但地质聚合物和碳-地质聚合物复合材料的毒性问题相对较少。
