10th U6+ Consortium of African Universities International Conference

Pharmaceutical effluents pose serious risks to aquatic systems and public health because they contain persistent organic pollutants, toxic metals, and active pharmaceutical compounds that are poorly removed by conventional treatment systems. This study evaluated three lime peel based filtration media (raw lime peel (LP), lime peel biochar (LB), and clay integrated lime peel biochar (CI-LB)) in gravity driven packed bed columns for treating real pharmaceutical wastewater. Material properties were examined using FTIR, SEM, XRF, and TGA/DTA/DSC to relate structure to treatment performance. CI-LB showed the best performance among the tested media. After 24 hours, CI-LB reduced copper, cadmium, nickel, zinc, and manganese to below detection limits. CI-LB also lowered total suspended solids by 50%, reduced biochemical oxygen demand by 11.6%, and removed 94.2% of methylene blue, compared with 78.5% for LB and 23.1% for LP. This higher performance is linked to the porous structure formed during carbonization, the added adsorption sites from clay minerals, and the hierarchical surface features that improve both physical retention and chemical binding. A key limitation was the rise in total dissolved solids and electrical conductivity caused by leaching of calcium and potassium salts. LP showed the highest TDS increase (190.6%), followed by CI-LB (113.1%) and LB (48.4%). These findings support CI-LB as a low-cost pretreatment medium, although post-treatment is needed to control salinity.