Vermistabilization: a sustainable strategy for the bioconversion and detoxification of textile industry sludge

Abstract Vermistabilization of the textile industrial sludge (TS) was carried out on a pilot scale with the help of the earthworm Eudrilus eugeniae. TS was mixed with cow dung (CD) in a ratio of 1:1 and thereafter subjected to vermicomposting for 90 days. Earthworms’ weights increased significantly by 55% in the feed mixture within 45 days of inoculation. Physicochemical parameters significantly reduced during vermicomposting (pH, EC, TDS, TOC, and NH3-N) whereas TKN, TP, TK were found to be significantly elevated in the final product. Except for Mn and Zn, the addition of amendments increased earthworm activity, which greatly reduced the content of heavy metals (Al, As, Cd, Cu, Pb, Ni, Cr, Mo, and Hg). Germination index (100%) of Brassica nigra was recorded in the feed mixture. The shoot and root length ranged from 2.26 and 4.36 after 90 days. Genotoxicity analysis revealed a 9.45–10.40% reduction in aberration frequencies of vermistabilized extracts in comparison with control (extracts of TS and CD only). The present study concluded that the deployment of vermistabilized extracts looks promising as a sustainable waste disposal management technology.