Effectiveness of Modified Pumice Stone in the Treatment of Waste Water from Tertiary Hospital

Pharmaceutical contaminants in hospital wastewater, such as Paracetamol, Aspirin, and Ibuprofen, pose substantial health and ecological risks. Conventional wastewater treatments are costly and ineffective at removing such contaminants, especially in developing countries. This study evaluated the effectiveness of modified pumice stone as a low-cost filtration medium for treating hospital wastewater.A laboratory experiment employed three continuous filtration tanks (15 cm × 15 cm × 15 cm) filled with coarse sand and granite (CSG), CSG with unmodified pumice stone (CSG/unmodified PS), and CSG with modified pumice stone (CSG/modified PS). Pumice stones were cleaned, pulverized, sieved, and modified to enhance adsorption. Wastewater collected from a tertiary hospital was applied at a hydraulic loading rate of 0.01 m for 8 days, with a 5-hour retention time. Pharmaceutical concentrations were determined using High-Performance Liquid Chromatography (HPLC), and physicochemical parameters were measured using APHA methods. Results were compared to NESREA standards.Initial concentrations of Paracetamol, Aspirin, and Ibuprofen were 162.2, 49.7, and 145.2 µg/L, respectively. After four days, concentrations in the CSG/modified PS setup dropped to 85.0, 22.3, and 72.7 µg/L, respectively. COD, BOD, and TSS decreased by 40–50%, and TN and TP by 35–45%. On the eighth day, BOD and COD in CSG/modified PS reached 18.6 mg/L and 33.5 mg/L, respectively—below NESREA limits.This study demonstrates that modified pumice stone significantly reduces pharmaceutical and physicochemical pollutants in hospital wastewater, offering a cost-effective treatment solution.