International Journal of Environment and Climate Change

The study investigated the potential of sand and activated charcoal filtration systems to enhance water quality for irrigation by treating aerated sewage effluent from. Setup involved a 60 cm deep sand filter connected as the inlet to another 30 cm deep sand filter and this filter linked as the inlet to a 30 cm deep charcoal filter. These filters were operated in series at hydraulic loading rates (HLR) of 60 m/h and 10 m/h. Notably, operating the filters in series at an HLR of 10 m/h yielded superior effluent water quality compared to an HLR of 60 m/h. System achieved significant removal efficiencies for turbidity, BOD₅, COD, Total Nitrogen (Total-N), Total Phosphorous (Total-P) with 71.9%, 54.4%, 71.9%, 44.4%, 39.1%, and 42.9% with a 90 cm deep sand filter at an HLR of 10 m/h, and also with a combination of sand and charcoal filters at an HLR of 25 m/h system achieved 81.6%, 80.3%, 63.5%, 47.5%, and 64.3% respectively. We also examined the chemical characteristics of both untreated and treated sewage water samples, revealing a hierarchy of cation and anion prevalence as follows: Na⁺ > Ca²⁺ > Mg²⁺ > K⁺ for cations, and Cl^- > HCO₃^- > SO₄^2- > CO₃^2- for anions. Our study demonstrates that the combination of aeration and sand filtration effectively ensures safety by preventing water body pollution and unpleasant odours with high-quality treated wastewater suitable for sustainable agricultural use.