Abstract
This study investigates the removal efficiency of various water contaminants using a Biological Sand Filtration (BSF) system under different operational conditions. The performance of the BSF system was evaluated for microbial contaminants (E. coli), suspended solids, dissolved solids (TDS), electrical conductivity (EC), hardness, chloride (Cl), sulfate (SO₄), and turbidity. Key operational parameters such as pH, retention time, flow rate, and the biological layer thickness were optimized to determine their impact on contaminant removal efficiency. The results demonstrated that a 48-hour retention time achieved complete E. coli removal (100%), while the 2 mm biological layer contributed to a significant reduction in microbial contaminants (81.2%). The highest turbidity reduction (85.4%) was achieved at a 0.5 m/h flow rate, and the pH 4.01 condition optimized the removal of TDS (65.4%) and EC (56.9%). Total hardness removal was maximized at 25°C, while magnesium removal was most effective with a 48-hour retention time (75.2%). Chloride removal peaked at 25°C (73.2%), and sulfate removal was optimized at pH 6.86 (52.9%). The study highlights the importance of adjusting operational parameters to optimize the performance of BSF systems for diverse contaminants, providing a sustainable and efficient solution for water quality improvement. The findings offer valuable insights for designing and operating BSF systems in varying environmental conditions and contribute to the development of cost-effective water treatment technologies.