Environmental remediation is a dynamic field aimed at removing pollutants from natural ecosystems. This chapter explores key pollutant degradation mechanisms, including biological, chemical, and physical methods, and their integration into water and soil remediation techniques. Fused S-heterocycles—compounds with unique chemical properties—play a central role in enhancing these processes. In biological remediation, they act as catalysts or mediators, boosting microbial activity and enzymatic processes. In chemical degradation, including advanced oxidation processes like photocatalysis and ozonation, fused S-heterocycles improve light absorption and electron transfer. Physical methods, such as adsorption and filtration, are optimized by incorporating these compounds into adsorbents. Water remediation techniques, including phytoremediation, bioreactors, and membrane filtration, are enhanced by fused S-heterocycles, which improve microbial activity, and membrane efficiency. These heterocycles offer eco-friendly, innovative solutions for sustainable, long-term environmental restoration.