Evaluation of Coagulation Using Different Coagulants and UV Irradiation for Organic Matter Removal from Real Hospital Wastewater

Hospital wastewater contains complex and biologically resistant organic compounds that threaten aquatic ecosystems and public health. This study evaluates the treatment efficiency of real infectious hospital wastewater using combined coagulation–flocculation and UltraViolet (UV) oxidation processes. Various coagulants, including polyaluminum chloride (PAC), polyacrylamide (PAM), aluminum sulfate, and FeCl₃, were evaluated using jar tests at different dosages and pH levels. The optimal combination of PAC and PAM (۰.۰۸ g each) achieved a maximum Chemical Oxygen Demand (COD) reduction of ۵۲.۹±۰.۲% (۶۱۹.۵۲ mg/L). In comparison, aluminum sulfate at a low dosage (۰.۰۲ g) demonstrated comparable efficiency (۴۸.۵±۰.۳% and ۶۷۶.۶ mg/L) with an optimal pH of ۸. UV irradiation further decreased COD by ۵۷.۶% (۵۵۸ mg/L) within ۳۰ min, indicating its strong potential for oxidizing persistent organics. The results demonstrate that the synergistic application of coagulation–flocculation and UV treatment substantially improves the effluent quality of hospital wastewater. This work provides practical insights into optimizing treatment processes for real infectious wastewater, supporting sustainable and safe hospital waste management strategies.

کلیدواژه ها:

Aluminum sulfate ، Chemical oxygen demand ، Coagulation&ndash ، flocculation ، Hospital wastewater ، UV treatment ، Zeta potential