Vermistabilization of textile mill sludge spiked with poultry droppings by an epigeic earthworm Eisenia foetida V.K. Garg * , Priya Kaushik Department of Environmental Science and Engineering, Guru Jambheshwar University, Hisar 125001, India Received 15 January 2004; received in revised form 3 September 2004; accepted 7 September 2004 Available online 11 November 2004 Abstract Investigations were made to explore the potential of an epigeic earthworm Eisenia foetida to transform textile mill sludge spiked with poultry droppings in to value added product, i.e., vermicompost. The growth and reproduction of E. foetida was monitored in a range of different feed mixtures for 77 days in the laboratory under controlled experimental conditions. The maximum growth was recorded in 100% cow dung (CD). Replacement of poultry droppings by cow dung in feed mixtures and vice versa had little or no effect on worm growth rate and reproduction potential. Worms grew and reproduced favourably in 70% poultry droppings (PD) + 30% solid textile mill sludge (STMS) and 60% PD + 40% STMS feed mixtures. Greater percentage of STMS in the feed mix- ture significantly affected the biomass gain and cocoon production. Net weight gain by earthworms in 100% CD was 2.9–18.2 fold higher than different STMS containing feed mixtures. The mean number of cocoon production was between 23.4 ± 4.65 (in 100% CD) and 3.6 ± 1.04 (in 50% PD + 50% STMS) cocoons earthworm À1 for different feed mixtures tested. Vermicomposting resulted in significant reduction in C:N ratio and increase in nitrogen and phosphorus contents. Total potassium, total calcium and heavy met- als (Fe, Zn, Pb and Cd) contents were lower in the final product than initial feed mixtures. Our trials demonstrated vermicomposting as an alternate technology for the recycling and environmentally safe disposal/management of textile mill sludge using an epigeic earthworm E. foetida if mixed with poultry droppings. Ó 2004 Elsevier Ltd. All rights reserved. Keywords: Vermistabilization; Eisenia foetida; Solid textile mill sludge; Poultry droppings; Biomass growth; Cocoon production; C:N ratio; Heavy metals 1. Introduction Disposal of industrial solids is becoming a serious problem. The improper and indiscriminate disposal of industrial solids is posing a great challenge to India and other developing nations. They cause odor problem and are potential source of surface and ground water pollution. The sludges resulting from different industrial operations and wastewater treatment plants are man- aged through destructive methods: land filling and incin- eration. The limited landfill space, more stringent National waste disposal regulations and public con- sciousness have made land filling increasingly expensive and impractical (Ndegwa and Thompson, 2001). There- fore, industries and municipalities in India are under heavy pressure and are in search of cost effective sustain- able technologies for the disposal of industrial sludges. It is well established that a large number of organic wastes can be ingested by earthworms and egested as peat like material termed as vermicompost. It is much more fragmented, porous and microbially active than parent material (Edwards, 1988; Edwards and Bohlen, 1996) due to humification and increased decomposition. Use of earthworms in the management of industrial 0960-8524/$ - see front matter Ó 2004 Elsevier Ltd. All rights reserved. doi:10.1016/j.biortech.2004.09.003 * Corresponding author. Tel.: +91 1662 275375; fax: +91 1662 276240. E-mail address: vinodkgarg@yahoo.com (V.K. Garg). Bioresource Technology 96 (2005) 1063–1071