? 2022 Elsevier B.V.The Si-O-Si moiety present in low-cost, easy-to-prepare geopolymers forms a part of the skeletal structure and does not participate in adsorption. In this work, a novel composite adsorbent (SGM-MDTC) was synthesized by grafting macromolecular dithiocarbamate (MDTC) on slag-based geopolymer microspheres (SGM), and the Si–O–Si in SGM was activated to enhance the Cd(II) adsorption performance of the geopolymer adsorbent. The SGM-MDTC was synthesized successfully and characterized using the XRD and FT-IR techniques. The Si-O-Si unit present in SGM was activated after anchoring MDTC. The activation was confirmed using the XPS technique. It was observed that the morphology of SGM and SGM-MDTC changed significantly, and the specific surface area of SGM increased from 52.99 to 72.36 m2/g following the process of MDTC anchoring. The effects of pH, the dosage of SGM-MDTC, contact time, and initial concentration during static adsorption on the adsorption performance of Cd(II) on SGM-MDTC were studied. It was observed that the process followed the pseudo-second-order kinetics, Langmuir, and Sip models and was primarily controlled by the process of intra-particle diffusion. The adsorption capacity of the synthesized SGM-MDTC (205.8 mg/g) material was nearly twice as high as that of SGM (106.7 mg/g) under conditions of static adsorption. Dynamic adsorption is more suitable for practical application than static adsorption. The adsorption capacity of SGM-MDTC was as high as 382.8 mg/g. This revealed that the synthesized SGM-MDTC material exhibited excellent Cd(II) purification performance and high application value.
Guangxi Key Laboratory for Polysaccharide Materials and their Modification Guangxi University for Nationalities College of Chemistry and Chemical Engineering Guangxi University for Nationalities
School of Chemistry and Chemical Engineering Guangxi School of Chemistry and Chemical Engineering Guangxi Key Laboratory of Petrochemical Resource Processing and Process Intensification Technology Guangxi University
NSTL
Elsevier
