Vermistabilization of waterhyacinth and secondary sewage sludge

Abstract

Water hyacinth, the invasive aquatic macrophyte, can be used as a bulking agent in vermicomposting of secondary sewage sludge. Vermicompost was obtained from different ratios of water hyacinth (WH) and secondary sewage sludge (SS). First set was prepared with 25 % WH + 75 % SS (Set 1), and the second set with 50 % WH + 50 % SS (Set 2). Vermicomposting of these two sets was done using the earthworm species Eisenia fetida . A seed germination test was performed to compare the efficiency of compost with normal (garden) soil. Four different seeds were taken for the experiment: Moong bean (Vigna radiata) , Guar (Cyamopsis tetragonoloba) , Fenugreek (Trigonella foenum-graecum) , and Mustard seeds (Brassica nigra) . After 7 days of growth, the seed vigour index was calculated for each seedling. Seeds grown in vermicompost obtained from sets 1 and 2 showed a higher seed vigour index compared to garden soil. It can be concluded that vermicompost obtained from these two substances is suitable for planting.