Preparation of magnesium slag-based porous materials and their performance for Pb2+ adsorption in wastewater

Magnesium slag-based porous materials (MSBPM) were prepared from magnesium slag by adding a composite exciter and foaming agent. Firstly, the effects of water glass modulus, alkali doping, blowing agent doping and roasting temperature on the mechanical and adsorption properties of MSBPM were investigated. The apparent morphology and porosity of MSBPM were observed and analyzed using scanning electron microscopy. Again, the adsorption performance of MSBPM on Pb2+ was investigated. The effects of parameters such as adsorbent dosing amount, initial concentration of solution, pH, adsorption time and temperature on the adsorption performance were studied. The results showed that the best adsorption performance of MSBPM on Pb2+ was achieved when the dosing of foaming agent was 8%, the dosing of alkali was 10% and the modulus was 1.3. The saturation adsorption capacity reached 303.95mg/g, which was 27% higher than that of the original magnesium slag. The compressive strength at this point was 2.84MPa. When the initial concentration of Pb2+ was 500mg/L, only 3.4g of adsorbent per liter of wastewater was required to achieve over 99% removal of Pb2+ . The adsorption process was monolayer chemisorption, which was in accordance with the proposed secondary kinetic model. © 2024 Chemical Industry Press Co., Ltd.. All rights reserved.