Incorporation of Earthworms and Dolochar in Biofilter: An Attempt Towards Maximizing Nutrients Removal

In the pursuit of finding an ecologically safe and sustainable technique for the remediation and reuse of effluents generated from the industries and housing colonies, biofilters have been considered. However, biofilters too have limitations such as low removal rate of nutrients. The present work is an attempt to enhance the nutrient removal potential of vermifilter, to make it more versatile. A layer of dolochar, a waste product from sponge iron industry, was added at the end of the horizontal vermifilters to assist in removal of nutrients. The resultant effluent from this setup was analyzed and monitored over a period of 60 days. The total phosphorus removal from the integrated setup was obtained between a range of 34.0–43.3%, while phosphate phosphorus removal was 46.6–61.3%. Total nitrogen removal also reached to a range of 8.3–23.7%. The study concludes that the incorporation of dolochar unit in vermifilter facilitates nutrient removal from wastewater and thus contributes toward reducing the increasing pollution load and minimizing scarcity of water by reusing the treated effluent from the vermifilter.