Vermistabilization of water hyacinth and secondary sewage sludge: a sustainable approach

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.

Keywords

• sewage sludge
• water hyacinth
• eisenia fetida
• vermicompost
• seed vigour index