Vermicomposting olive mill waste

Abstract

This study focuses on examining whether vermicomposting serves as a viable means to sustainably handle olive mill waste (OMW) which represents the major agro-industrial byproduct across Mediterranean regions. The high phenolic content of untreated OMW along with its low biodegradability and phytotoxic nature create notable environmental hazards. The study examines how the combination of OMW with animal manure through vermicomposting reduces toxicity levels while promoting nutrient equilibrium and sustaining earthworm populations. The study aims to achieve four specific objectives which include detoxifying OMW, cutting organic waste amounts, producing enhanced compost, and developing optimal feedstock combinations for successful vermicomposting. The research analyzes the chemical and physical alterations which take place in vermicomposting through monitoring pH levels along with electrical conductivity measurements and moisture content together with C/N ratios. The nutrient-rich properties of manure combined with its high microbial content support optimal conditions for earthworm development and reproduction while boosting enzyme activity. The obtained vermicompost showed better nutrient composition levels for NPK and micronutrients along with stable organic matter content and beneficial microbial strains for plant growth. A germination test using lettuce seeds confirmed that the final compost product was free from toxicity which makes it suitable for organic agriculture purposes. This research identifies OMW-manure co-vermicomposting as an economical method which converts harmful waste into valuable biofertilizers for sustainable agricultural development through circular economy practices.