Vermi-Biofiltration- A Low Cost Treatment for Dairy Wastewater

The wastewater generated in dairy industry contains very high organic loading and total solids and is mostly treated in ETP (Effluent Treatment Plant) plant, where the sludge is formed increasing the expenditure for processing and disposal along with the operation cost. Vermi-bio-filtration is a combination of conventional filtration process along with vermicomposting. Earthworms body act as a biofilter and they were found to decrease BOD-97.95 %, COD-91.64 %, TSS-76.39 %, TDS-84.27 %. Oil and grease content was also found to be reduced by 84.13 %. They treat the wastewater by the mechanism of feeding and biodegradation. Also increase the hydraulic conductivity and natural aeration by grinding the soil particle. In the present study vermifilter was designed. The effluent passed through top layer of the filter and found out the efficiency of removal of physicochemical parameter. The suspended solids trapped on top of the vermifilter and processed by earthworms. There is no sludge formation in this process which requires additional expenditure on landfill and disposal. The process is odour-free, ecofriendly and cost effective. The final vermi-filtered water was clean enough to be used for irrigation, in parks, and garden.