Statistical analysis of pesticide removal by natural and waste-based adsorbents: a novel method for quantitative and green suitability assessment (GSI)

The accumulation of pesticide residues in aquatic environments poses significant environmental risks to ecosystem integrity and human health. This study systematically reviewed 77 peer-reviewed studies (2008–2025) on natural and waste-based adsorbents used for pesticide removal from water and conducted a comprehensive evaluation based on green chemistry principles. Adsorbent types, target pesticide groups, and removal methods were classified and statistically analyzed. A novel Green Suitability Index (GSI) was developed to quantitatively assess the environmental compatibility of adsorbents. The index is based on four main criteria: raw material renewability, process chemical minimalism, post-use waste and environmental risk, and energy–carbon reduction, producing a composite score on a 0–12 scale, where higher scores indicate stronger alignment with green chemistry principles. The findings revealed that agricultural waste-based adsorbents were the most studied group and achieved the highest environmental suitability (mean GSI = 11/12, SD = 2.75; ≈92%), followed by plant-derived natural adsorbents (mean GSI=9/12, SD = 2.25; ≈75%). In contrast, nano/modified adsorbents showed the lowest green compatibility (mean GSI = 4/12, SD = 1.00; ≈33%) due to higher synthesis energy demands and reagent use. Organophosphate pesticides were the most frequently targeted contaminants. Overall, the results demonstrate that natural and waste-based adsorbents combine high removal efficiency with superior green chemistry compliance, offering sustainable and low-impact alternatives for pesticide pollution control and eco-friendly water treatment applications.