Dried MoS2–Cobalt Alginate Membrane for Rapid Catalytic Degradation of Methylisothiazolinone

The rapid development of industry has led to the discharge of large quantities of organic pollutants into water bodies, posing a significant threat to aquatic safety. It is imperative to develop efficient and environmentally friendly methods for the elimination of organic pollutants. The integration of hydrogel membranes with advanced oxidation processes (AOPs) for water purification has attracted considerable interest due to their high efficiency. However, conventional wet membrane materials stored in aqueous environments are more prone to swelling and leakage of loaded metal species. This limits its application in the degradation of organic pollutants. This study employs a vacuum drying strategy for wet hydrogels, incorporating molybdenum disulfide as a cocatalyst and Co²⁺ cross-linking within the alginate matrix, resulting in a dried MoS₂-cobalt alginate hydrogel membrane (D-MoS₂-CoAlg). The drying process of the D-MoS₂-CoAlg membrane not only significantly enhanced its mechanical strength and anti-swelling capacity but also effectively mitigated the leaching of Co²⁺. Throughout five consecutive cycles, the concentration of leached Co²⁺ remained below 0.032 mg/L. This enables the membrane to achieve a balance between reusability and environmental compatibility. Under the conditions of a drying time of 60 min, a peroxymonosulfate (PMS) dosage of 0.2 mmol/L, and an initial methylisothiazolinone (MIT) concentration of 20 mg/L, the D-MoS₂-CoAlg membrane exhibited exceptional catalytic performance, achieving a degradation rate of MIT as high as 92.14% within 5 min. The D-MoS₂-CoAlg membrane demonstrates high catalytic activity and good stability, showing promising potential for application in the field of organic wastewater treatment.