Greywater treatment by vegetated vermifilter: A low cost material for rural sanitation in India

Abstract

Recycle and reuse are the best options to deal with water scarcity. An attempt is made to reuse greywater after giving low cost effective treatment with the help of vermifilter.A laboratory scale vegetated vermifilter system consisting of Sand Gravel Filter (SGF), and Laterite Soil Vegetated Vermifilter (LSVVF)/Laterite Soil Vegetated filter (LSVF) for the treatment of greywater was developed. The developed treatment system was evaluated for its performance by varying OLR and HRT. The removal efficiency for BOD5, TKN and P using LSVF was observed to be 50–60%, 30–50% and 30–50% respectively. The corresponding values in LSVVF were 60–80%, 40–64% and 35–68%. The earthworm plays vital role in removal of organic matter. There is no detrimental effect on earthworm survival and growth observed during study period. HRT of 3 d for the system is appropriate for reducing BOD5 to a value less than 20 mg/L for an OLR up to 145 kgBOD5/ha d. The vegetated vermifilter was found useful for the treatment of greywater. It provides a low-cost, efficient, easily operable/maintainable and least mechanized option for greywater treatment in a decentralized system. This system is suitable for rural sanitation in developing country like India.