Continuous flow-through vermireactor for medium scale vermicomposting

Abstract

Vermicomposting is increasingly becoming popular as an organic waste management technology whereby earthworms feed on the organic waste to produce vermicasts and vermiwash. Several vermireactors have been used for this process as batch systems. However, there is need to design a continuous flow-through vermireactor which allows the simultaneous addition of the organic waste at the same time harvesting the vermicasts. A 5m X 2m X 1.5m vermireactor was proposed to process an initial feed of 7 500kg. A 10cm thick bedding comprising of office paper, card board paper and Eisenia fetida earthworms stocked at 1kg/m2 of the vermireactor was used as an initial bedding. The feed bed was 20cm thick and comprised of paper, cow dung, corn pulp and vegetables. The pH, temperature and moisture content in the vermireactor ranged between 5.5-7.5, 19-25°C and 28-52% respectively. 7kg/day of vermicasts were produced given the earthworms produced 75% of their bodyweight as vermicasts per day. The caked vermicasts were expelled by the aid of a breaker bar. The vermireactor was constructed from polyvinyl chloride. Vermicasts containing nitrogen (4.19%), phosphorous(1.15%) and potassium (6.18%) were obtained. The continuous flow-through vermireactor design allowed the production of stable vermicasts and can be used in medium scale vermicomposting.Vermicomposting is increasingly becoming popular as an organic waste management technology whereby earthworms feed on the organic waste to produce vermicasts and vermiwash. Several vermireactors have been used for this process as batch systems. However, there is need to design a continuous flow-through vermireactor which allows the simultaneous addition of the organic waste at the same time harvesting the vermicasts. A 5m X 2m X 1.5m vermireactor was proposed to process an initial feed of 7 500kg. A 10cm thick bedding comprising of office paper, card board paper and Eisenia fetida earthworms stocked at 1kg/m2 of the vermireactor was used as an initial bedding. The feed bed was 20cm thick and comprised of paper, cow dung, corn pulp and vegetables. The pH, temperature and moisture content in the vermireactor ranged between 5.5-7.5, 19-25°C and 28-52% respectively. 7kg/day of vermicasts were produced given the earthworms produced 75% of their bodyweight as vermicasts per day. The caked vermicasts were expelled by the aid of a breaker bar. The vermireactor was constructed from polyvinyl chloride. Vermicasts containing nitrogen (4.19%), phosphorous(1.15%) and potassium (6.18%) were obtained. The continuous flow-through vermireactor design allowed the production of stable vermicasts and can be used in medium scale vermicomposting.