A Comprehensive Review of Highly Porous Adsorbent Materials for Organic Pollutant Removal

The contamination of water bodies with organic pollutants such as phenols, polycyclic aromatic hydrocarbons (PAHs), synthetic dyes, pharmaceuticals, and pesticides has become a pressing environmental concern due to their persistence, toxicity, and potential for bioaccumulation. Among various remediation strategies, adsorption using highly porous materials has emerged as a highly effective and versatile approach. This review comprehensively evaluates the structural and functional characteristics of key porous adsorbents, including activated carbon, biochar, mesoporous silica, graphene-based materials, carbon nanotubes, metal–organic frameworks (MOFs), and polymeric resins. The mechanisms of adsorption, including physical adsorption, chemical interactions, π–π stacking, hydrogen bonding, electrostatic interactions, and hydrophobic effects, are analyzed in relation to pollutant type and material properties. Factors affecting adsorption performance such as pH, temperature, contact time, adsorbent dosage, agitation speed, ionic strength, and competing ions are also discussed. Comparative performance analysis, regeneration strategies, challenges, and research gaps are highlighted to guide future development. The review identifies trends toward hybrid and multifunctional adsorbents, green synthesis, and integration with advanced treatment technologies, emphasizing the potential for designing high-performance, sustainable adsorbent systems for effective wastewater remediation