Vermiremediation and comparative exploration of physicochemical, growth parameters, nutrients and heavy metals content of biomedical waste ash via ecosystem engineers Eisenia fetida

Abstract

Vermicomposting of Biomedical waste ash (BA) by the earthworm Eisenia fetida was studied with cow dung (CD) as nutrient medium. For 105 days, experiment was carried out in seven vermireactors containing varying ratios of BA and CD. Earthworm activity significantly reduced the pH (8.61–7.24), Electrical conductivity (EC) (4.1–1.62), Total organic carbon (TOC) (38.6–14.92), and Carbon and nitrogen (C/N ratios) (145.4–8.2) of all BA ratios. Levels of Total kjeldahl nitrogen (TKN) (0.26–1.82), Total available phosphorus (TAP) (0.22–0.64), Total potassium (TK) (2.05–12.08), and Total sodium (TNa) (47.53–92.26) were found to be increasing in the postvermicompost mixture. Although heavy metals content decreased from initial to final, it becomes below the permissible limits in the end product. The results showed that earthworm growth and fecundity were best in vermireactors containing 10–25% of BA. The best reproduction and growth of earthworms, demonstrate the vermicomposting's ability to manage hazardous solid wastes like BA. Use of vermitechnology to manage BA has not been performed yet in any kind of the research. Finally, it was determined that vermicomposting can be incorporated into overall plan for BA management. Thus nutrient-rich, detoxified, and physiochemically stable product may be used safely in agricultural processes.

Keywords

• Hazardous solid wastes
• Vermicomposting
• Reproductive parameters
• Permissible limits
• Vermireactors
• Earthworms