India’s escalating water scarcity, combined with declining groundwater quality, calls for decentralised and low-cost wastewater treatment solutions that can ensure sustainable household water reuse and groundwater recharge. This study developed and evaluated a laboratory-scale greywater filtration and soil aquifer treatment (SAT) system using sand and granular activated carbon (GAC) as primary filter media. Greywater was collected from kitchen and bathroom–laundry sources in Vellore, Tamil Nadu, in a 3:7 ratio and treated through a two-stage system comprising a slow sand–GAC filtration column followed by a soil infiltration pond. The filtration column achieved significant removal of suspended solids and organics, while the SAT unit provided advanced polishing through microbial degradation and ion exchange. Analytical results revealed sharp reductions in turbidity (72.4%), total solids (15.7%), COD (99.5%), nitrate (91.1%), TKN (63.6%), and chlorides (94.8%). The final effluent parameters complied with CPCB discharge and approached BIS drinking-water standards, confirming its suitability for non-potable reuse and groundwater recharge. Compared to previous natural-media filtration systems the present system which is combination of filtration and SAT achieved superior efficiency with shorter retention time and minimal operational demand. This compact, low-energy, and easily replicable unit demonstrates a promising pathway for household-scale wastewater management in water-stressed regions.
Rejikumar et al. (Tue,) studied this question.