Effective adsorbents for the removal of pesticides from contaminated water

ABSTRACT Pesticide contamination of water resources has become a growing environmental and public health concern due to the widespread use of agrochemicals in modern agriculture. Although pesticides contribute significantly to crop protection and food productivity, their persistence, mobility, and toxicity can lead to contamination of surface water, groundwater, soil, and aquatic ecosystems. Various treatment technologies, including advanced oxidation processes, membrane filtration, electrochemical treatment, adsorption, and chemical precipitation, have been applied for pesticide removal. Among these approaches, adsorption has received increasing attention because of its simplicity, high efficiency, operational flexibility, low cost, and limited generation of harmful by-products. This review evaluates the effectiveness of different adsorbent materials for removing pesticide residues from contaminated water, with emphasis on activated carbon, biosorbents, natural inorganic adsorbents, metal-organic frameworks, and covalent organic frameworks. The adsorption performance is discussed in relation to surface area, pore structure, functional groups, pH, contact time, adsorbent dosage, pesticide concentration, and adsorption mechanisms such as physisorption, chemisorption, hydrogen bonding, electrostatic attraction, and π–π interactions. The review highlights that agricultural waste-derived activated carbons and biosorbents are promising sustainable alternatives because they are abundant, low-cost, renewable, and environmentally friendly. Advanced framework materials such as MOFs and COFs also show high adsorption capacity and selectivity, although their cost, stability, and scalability remain key challenges. Overall, naturally occurring and minimally modified materials demonstrate strong potential for pesticide remediation in water systems. Future research should focus on real wastewater applications, regeneration, reuse, spent adsorbent management, life-cycle assessment, and pilot-scale implementation.