Experimental process monitoring and potential of Eudrilus eugeniae in the vermicomposting of organic solid waste in Mauritius

• Vermicomposts have less risk of ecological contamination due to low metal contents.
• Earthworm activity in the waste decomposition vessels accounted for the metal loss.
• Nutrient level of vermicompost depends on type and amount of waste which was used.
• Eudrilus eugeniae was found to be an effective accumulator of several toxic metals.
• Quality test data indicated potential of using Eudrilus eugeniae in vermicomposting.

This study was undertaken to assess the experimental process monitoring during the vermicomposting of organic solid waste (OSW) utilizing Eudrilus eugeniae as earthworm species. Three mixes for the vermicomposting of OSW were set up separately in three 244 L vermibins and denoted as M1, M2 and M3. M1 represented the food waste mix; M2 represented the paper waste mix and M3 for the yard waste mix. An increase in wet bulk density with a maximum value of 424.0 ± 8.7 kg/m3, 573.3 ± 9.9 kg/m3 and 349.7 ± 6.4 kg/m3 was noted for M1, M2 and M3, respectively. The net degradation of the vermicompost pile in terms of volatile solids reduction was 80.58% for M1, 61.03% for M2 and 77.51% for M3. The value of C:N ratios depicted an overall decrease of 41.5–48.4% in the final mixtures. The growth rate of E. eugeniae in the vermicomposting mixes was 3.33 g day−1, 3.47 g day−1 and 1.67 g day−1 for M1, M2 and M3 respectively and the mean size of the cocoons produced was 4.26 mm × 2.82 mm. Results suggested vermicomposting as an appropriate technology for bioremediation of heavy metals from OSW. Data implied that there is a huge scope for the implementation of vermicomposting technology on a countrywide basis by the scientific community of Mauritius considering the quantities and properties of OSW generated.