Dynamics of vermicomposting of solid textile mill sludge spiked with various organic wastes

In our laboratory the work is in progress to demonstrate the management of solid textile mill sludge (STMS) by vermicomposting. The laboratory based experiments have been conducted on vermicomposting of STMS spiked with cow dung (CD), biogas plant slurry (BPS), poultry droppings (PD) and agricultural residues. The results showed that Eisenia foetida did not survive in fresh STMS. The maximum growth and reproduction was in 100 % CD but worms grew and reproduced in those feed mixtures also which contained 20-30 % STMS. Vermicomposting resulted in significant reduction in C: N ratio and increase in total nitrogen content. Total potassium content, calcium content and heavy metals ’ (Fe, Zn, Pb and Cd) content were lower in the final product than initial feed material. Microbial activity measured as dehydrogenase activity increased with time up to day 60 or 75 but decreased on day 90 indicating the exhaustion of feed and decrease in microbial activity. Replacement of CD by PD and BPS had no significant effect on vermicompost quality. These experiments demonstrate that vermicomposting can be an alternate technology for recycling and environmentally sustainable management of STMS using an epigeic earthworm Eisenia foetida