Vermicomposting of herbal pharmaceutical industry waste: Earthworm growth, plant-available nutrient and microbial quality of end materials

► Herbal pharmaceutical industrial waste (HPIW) spiked with cow dung (CD) was decomposed using vermicomposting. ► Vermicomposting caused significant decrease in total organic and C:N ration of wastes. ► The processed material was rich in plant available nutrients (N-NO3−, SO4−2, PO4−3 and available K). ► Vermicomposting also enriched the processed material with populations of fungi, bacteria and actinomycetes. ► The results suggested the suitability of vermitechnology for HPIW recycling.