Optimization of Alum Sludge-Enhanced Pervious Concrete Filters for Amoxicillin Removal from Aqueous Solutions

This study investigates the performance of Alum Sludge-Enhanced Pervious Concrete Filters (ASPCFs) as a sustainable and cost-effective solution for removing amoxicillin (AMX) from aqueous solutions. By leveraging alum sludge as a daily waste material from water treatment plants, this approach promotes environmental remediation and resource recycling. Six filters were manufactured, each containing a uniform amount of pervious concrete and varying amounts of alum sludge (0–25 kg/m³). The AMX-containing water was allowed to flow through the filters under gravity. Key parameters such as alum sludge content, pH value, dissolved oxygen (DO), and chemical oxygen demand (COD) were monitored. The adsorption kinetics and isotherms were analyzed to understand the removal mechanisms. The results revealed that the ASPCF (M5) with 25 kg/m³ alum sludge achieved a remarkable 97.14% AMX removal rate over thirteen days of continuous operation. Significant COD removal performance was also observed, with an average removal rate of 86.11% for the ASPCF (M5) at the same alum sludge content (25 kg/m³). The adsorption kinetics followed the pseudo-second-order model, and the Freundlich isotherm provided the best fit for the adsorption data. ASPCF M5, with a treatment cost of $0.009 per g AMX removed and an AMX removal efficiency of 97.14%, is a cost-effective and competitive technique for wastewater treatment. Highlights • ASPCFs with 25 kg/m³ alum sludge achieved 97.14% amoxicillin removal. • ASPCFs showed 86.11% COD removal, outperforming conventional sand filters. • Amoxicillin adsorption fits the Freundlich model and pseudo-second-order kinetics. • Alum sludge enhances adsorption capacity and maintains stable pH and DO levels. • ASPCFs are cost-effective and sustainable for water treatment. Graphical Abstract