Poornachandra Shamanna Prabhakar, Shivakumar, Asha Danthi, Parveen Shaik, Amgoth Ramesh, T N Varshitha, Udaya Kumar Dalimba, B C Revanasiddappa
Environmental pollution, climate change, and increasing demands for sustainable remediation require adsorbents that combine high efficiency with selectivity, stability, and regenerability. Porous organic polymers (POPs) have emerged as versatile platforms because their covalently linked networks, permanent porosity, and tunable surface chemistry enable molecular-level control of pollutant-framework interactions. This review critically examines major POP families, including hypercrosslinked polymers, conjugated microporous polymers, porous aromatic frameworks, covalent organic frameworks, and covalent triazine frameworks, with emphasis on the relationships among pore architecture, surface functionality, charge distribution, and environmental performance. Recent applications in CO2 capture, volatile organic compounds, heavy metals, radionuclides, dyes, pharmaceuticals, pesticides, and other organic pollutants are evaluated across water, air, and soil remediation. Particular attention is given to adsorption mechanisms, selectivity, regeneration, moisture tolerance, long-term stability, and practical deployment through membranes, fibers, aerogels, and hybrid systems. Emerging green synthesis strategies, including aqueous, solvent-free, mechanochemical, microwave-assisted, catalyst-free, and biomass-derived approaches, are assessed in terms of sustainability and scalability. The review further considers barriers to commercialization, including precursor and processing costs, regeneration energy, performance in complex environmental matrices, continuous-flow operation, and competition with established low-cost adsorbents such as activated carbon. Finally, opportunities involving stimuli-responsive and multifunctional POPs, hybrid technologies, and machine-learning-assisted materials design are discussed as pathways toward sustainable, selective, and application-oriented environmental remediation.