The Utilization of Biofilter Technology for Domestic Wastewater Treatment in Support of Aquatic Conservation

Domestic wastewater is one of the major contributors to water pollution in urban and rural areas, particularly when discharged without proper treatment. This study aims to evaluate the effectiveness of a simple biofilter system using natural materials gravel, zeolite, and activated carbon in reducing pollutants from household greywater. A vertical-flow biofilter reactor was constructed and tested over a 30-day period, using a pretest-posttest experimental design. Water quality parameters such as Biological Oxygen Demand (BOD), Chemical Oxygen Demand (COD), Total Suspended Solids (TSS), and pH were measured before and after filtration. The results showed significant reductions in pollutant concentrations: BOD decreased by 73–77%, COD by 62–65%, and TSS by 85–90%, while pH remained stable in the neutral range. Statistical analysis confirmed that these reductions were significant (p < 0.05). The biofilter also improved the visual clarity and odor of the water, making it suitable for non-potable reuse. Given its low cost, ease of construction, and reliance on locally available materials, this biofilter system is highly suitable for decentralized wastewater treatment, especially in areas without centralized infrastructure. The system also supports aquatic conservation efforts by reducing pollutant loads discharged into natural water bodies.