Studies on Vermifiltration of Restaurant Effluent and Reuse in Benue State, North Central, Nigeria

Abstract

Vermifiltration was used for the treatment of restaurant effluents in Benue state. Four vermi-bio-filters were used; V1 (Lumbricusterritris), V2 (Eudriluseugeniae), V3 (Eiseniafetida), V4 (mixture of Lumbricusterritris, Eudriluseugeniae and Eiseniafetida) and V5 (Control without earthworm-geofilter). The effluent from vermifilters and control were analysed for microbial load. The Earthworms' body worked as a 'biofilter' and as a bioreactor with the mechanism of 'ingestion' and biodegradation of organic wastes. Bacteria analysed in the six effluents (Staphylococcus spp, Streptococcus spp, Escherichia coli, Salmonella spp, Enterobacterspp, Proteus spp and Pseudomonas spp) and fungi (Aspergillus, Penicillium Rhizopus and Mucor. Saccharomyces cerevisae) were reduced in the range of 70.0-97.7% and 68.3-97.4% respectively. Analysis of Variance (ANOVA) to determine the differences in microbial load concentration between the influent and effluent were considered significant at 5% level (p ≤0.05). The synergistic action of enzymes, microorganisms and earthworms significantly reduced the amount of microbial load compared to a geo-filter, without earthworms' presence (control). Vermifiltration is a low cost technology recommended for treatment of effluent before discharge into the environment. This is an odor-free process and no sludge formed in vermin-filtration. Vermifiltration technology can be applied as an environmentally friendly technique as the treated effluents met the set standards for irrigation purpose, parks, gardens and hydroponics.