LAUSR

Abstract Solid wastes exhibit excellent prospects in the removal of heavy metals from contaminated water. However, raw solid waste materials usually show mediocre uptake efficiency, it is imperative to functionalize or transform them into new solid waste-based materials. The present work provides a novel technique by utilization of silica fume waste for Ni2+ removal from wastewater. The sorbent was prepared by in-suit conversion of amorphous silica fume based geopolymer into monolithic ZSM-5 via polycondensation and seed-induced hydrothermal treatment process. The adsorption behavior of Ni2+ in aqueous solution onto the as-synthesized monolithic ZSM-5 was investigated. The adsorption experiment data fitted well with the pseudo-second-order kinetic model and Langmuir isotherm model. Thermodynamic parameters including ΔH, ΔG and ΔS were calculated from the temperature-dependent sorption isotherms. All the results confirmed that the sorption of Ni2+ onto monolithic ZSM-5 was a spontaneously endothermic chemisorption process, demonstrating the removal of Ni2+ from wastewater using monolithic ZSM-5 was feasible. The adsorption capacity of Ni2+ onto monolithic ZSM-5 was 13.22 mg/g at 25 °C, which was a competitive result compared with similar adsorbents and commercial ZSM-5 powders.