Development of Composite Radial Filter for Recharging Aquifers with Canal Water

A laboratory scale model of composite radial filter was designed, fabricated and tested for recharging aquifer with canal water. Charcoal (C), coarse sand (CS) and gravel (G) filter materials were placed in annular rings of developed radial filter in different combination of thickness, viz. 1 : 1 : 1, 1 : 1 : 2, 1 : 2 : 2 and 1 : 2 : 1 for four treatments T₁, T₂, T₃ and T₄ respectively. Flow equation for discharge through composite radial filter was developed and verified through experiments. The design depth of the filter for given discharge was also obtained. Sodium hypochlorite solution was injected through chlorination unit at the outlet of the radial filter to remove the bacteriological contamination of filtered water. The performance of composite radial filter was evaluated by analyzing canal water before and after filtration. Water quality parameters of filtered water were found to be within permissible limit at low flow rate (0.3 lps). The water quality parameters of filtered water from treatment T₃ with thickness of 10, 20 and 20 cm for C, CS and G respectively was found to be comparatively better than other three treatments (T₁, T₂ and T₄). The composite radial filter consists of C, CS and G filter media having thickness in ratio of 1 : 2 : 2 was found to be the best for recharging groundwater aquifer with canal water.