Sulfadimethylpyrimidine degradation by non-radical dominated peroxomonosulfate activated with geopolymer-loaded cobalt catalysts

Geopolymers are frequently employed as adsorbent materials to treat heavy metals in wastewater due to their special structure analogous to that of zeolites. Nevertheless, their utilization as catalyst supports has not been extensively employed. In this study, geopolymers were modified using carboxymethyl chitosan and subsequently converted into zeolite through the hydrothermal method. Following calcination with Co loading, Co@MGA was obtained. The results indicated that as-prepared Co@MGA exhibited an excellent performance in activating PMS to degrade SMT. Moreover, the mineralization rate of SMT reached 76 %. Quenching experiments and electron paramagnetic resonance analyses had demonstrated that the non-radical pathway predominated in the degradation process of SMT, and 1O2 was the primary reactive oxygen species. The formation of surface bond was further elucidated through in-situ Raman spectroscopy and electrochemical tests. The potential mechanism and pathways of SMT degradation within the Co@MGA/PMS system were proposed. The system exhibited adaptability to different pH levels and robust resistance to inorganic ions and humic acid. Co@MGA demonstrated excellent reusability and stability, suggesting that Co@MGA is a highly promising catalyst for the activation of PMS. [Display omitted] •A geopolymer-supported cobalt catalyst (Co@MGA) was synthesized.•SMT degradation in the Co@MGA/PMS system followed a non-radical mechanism.•1O2 was the primary ROS in the Co@MGA/PMS system.•The non-radical process was less influenced by ions and pH.•The mineralization rate of SMT in the Co@MGA/PMS system achieved 76 %.