Synthesis of inverse vulcanized sulfur based polymer using emulsion polymerization and its application as removal of lead ions from the wastewater

This study synthesized sulfur copolymers using emulsion polymerization for versatile applications, especially in wastewater treatment. The emulsion method overcomes heat and mass transfer issues in polymerization and demonstrates significant potential for scalability in the wastewater industry, enabling the efficient production of copolymers for large-scale operations. These scalable processes can be adapted to meet industrial wastewater treatment demands, enhancing the feasibility of heavy metal removal at a commercial level. The sulfur emulsion copolymers were made with sulfur as a carrier, ethylene diamine as a solvent, span 80 as an emulsifying agent, and sulfuric acid for stripping. Factors like sulfur concentration (0–40 % v/v), stripping phase (1 M H2SO4), emulsification speed (200–800 rpm), time (5–30 min), and volume ratio (1–1.5) were optimized for stability and heavy metal removal. Characterization techniques (optical microscopy, XRD, FTIR NMR, Raman spectroscopy, SEM, TEM, TGA) confirmed sulfur-amine complexes and amorphous sulfur. Emulsions with up to 30 % sulfur maintained stability and achieved maximum lead ion adsorption around 422 µg/g, corroborated by ICP-OES analysis. The sulfur emulsion copolymers have ability to remove 80 % of lead ions from wastewater. Lead sulfate formation indicated chemisorption, supported by the DKR model for data representation and pseudo-first-order kinetics. ICP-OES confirmed successful Pb2 + ion elimination, validating the removal process.