Comparative Evaluation of UiO-66 and Natural Coagulants for Turbidity Removal from Surface Water

Abstract

Turbidity removal is a critical step in surface water treatment. This study presents a comparative evaluation of Metal-Organic Framework (UiO-66) nanoparticle, Moringa oleifera (MO) seed powder, Azadirachta indica (AI) seed powder as coagulants for turbidity removal from simulated and surface water. Coagulation-flocculation experiments were conducted using simulated water (212 NTU) and turbid water from a mining pond (7 NTU, pH 6.9). The effects of coagulant dosage (0.06–0.30 g), settling time (30 min–3 hours), and different coagulant combinations (ratios 1:1 to 1:9) were evaluated. Results showed UiO-66 nanoparticle had highest removal (99.53–100%), at optimal conditions (0.18 g dosage, 3 hour settling), MO (97.64%) and AI(95.28%). Coagulant combinations showed MOF/MO (1:5 ratio) 91.98%, MOF/AI (1:5) 91.04% removal. Increasing coagulant dosage improved removal efficiency from (0.18–0.24 g). Physicochemical properties of treated turbid water showed improvements: pH (6.5–6.8), alkalinity (120 to 21–30 mg/L, (MOF), total hardness (24 to 8–11 mg/L), TDS (40 to 10–26 mg/L), nitrate (60 to 9–36 mg/L), phosphate (27 to 5.4–17.6 mg/L). UiO-66 nanoparticle demonstrated superiority across all parameters. This study establishes UiO-66 as an effective coagulant for turbidity removal, potential for integration with natural coagulants is an alternative for sustainable water treatment.