Recycling of lime sludge emanating from tannery industry through vermicomposting using Eisenia foetida

The research was focused on the control of pollution, which is caused due to tannery waste disposal, through the process of vermicomposting. Earthworms have increasingly been used for waste management. Therefore, the main aim of this study was to recycle the lime sludge emanating from a selected tannery industry through vermicomposting. Tannery solid waste was allowed to compost for 60 days, and then the composts were harvested and analyzed for selected physio-chemical and biochemical parameters. A flowering plant namely Tagets erecta Linn was grown in soil mixed with the vermicomposts obtained, and was studied for its growth attributes and compared with the control plant growth on soil alone. The attributes studied were biometric parameters, like root length, shoot length, plant height, plant weight, number of leaves, flowers and buds. The alkaline nature of the lime sludge was reduced to neutral range on vermicomposting. The electrical conductivity of the lime sludge was also reduced on vermicomposting which might be due to the transformation of complex organic compounds into simpler forms. The biochemical parameters, such as nitrogen and carbon were also reduced on vermicomposting.