Vermicomposting of paper mill solid waste using epigeic earthworm Eudrilus eugeniae.

Area of Science:

• Environmental Science
• Soil Science
• Waste Management

Background:

• Organic waste management is a global challenge.
• Vermicomposting offers a sustainable solution for waste decomposition.
• Eudrilus eugeniae is an exotic earthworm species with potential for waste valorization.

Purpose of the Study:

• To evaluate the efficiency of Eudrilus eugeniae in decomposing mixed liquor suspended solids (MLSS), cow dung (CD), and leaf litter (LL).
• To determine optimal substrate ratios for vermicompost production and earthworm health.
• To assess the potential of vermicomposting for managing MLSS and nutrient recovery.

Main Methods:

• A 90-day study using Eudrilus eugeniae with eight different substrate ratios of MLSS, CD, and LL.
• Three replicates per treatment, with measurements of pH, organic carbon, C:N ratio, total nitrogen, phosphorus, and potash.
• Monitoring of earthworm zoo mass and mortality rates.

Main Results:

• All vermibeds showed decreased pH, organic carbon, and C:N ratio, with increased total nitrogen, phosphorus, and potash.
• Optimal decomposition and nutrient content occurred in a 1:1:2 ratio of CD + MLSS + LL.
• Earthworm mortality increased with higher MLSS proportions, with maximum mortality in pure MLSS.

Conclusions:

• Eudrilus eugeniae effectively converts organic waste into valuable vermicompost.
• Vermicomposting is a viable low-input method for managing MLSS energy and nutrients.
• The resulting vermicompost can support sustainable land restoration practices.