Epsilon Archive for Student Projects

Abstract

Dry sanitation approach, where there is no need for water-flush, is a low-cost technology that has gained interest in recent years, and the focus in this study is vermicomposting as an on-site toilet system that can be used to reduce the wastewater released into the environment. A toilet design outline was used to illustrate and create a functioning vermicompost unit, whereby faeces was added into the vermicomposting unit on a daily-basis, to simulate an on-site urine diverting toilet. The earthworms used were Esenia fetida and the average feeding rate per adult worm of 0.02g/day and this system had a continuous (daily) faecal feeding that began at 80g/day for 3 weeks to 120g/day for 8 weeks. The indicator micro-organisms Enterococcus spp. and Escherichia spp. and pathogen Salmonella spp. were monitored and reduced in terms of concentration from 9 log10, 7 log10, 6.5 log10 respectively to 5 log10, 2.5 log10 and 3 log10. The bacteriophages MS2 and ΦX174 were also evaluated to no significant reduction within the vermicompost unit. A total material added into the vermicompost on a VS basis was 2.5 kg with an output material being that of 0.9 kg which gave a material mass balance reduction of 63 % (VS basis). The continuous faecal loading preceded in a gradual faecal build-up that did not affect the system from achieving this material reduction. Therefore, the vermicomposting system with its material reduction was seen as a viable dry sanitation approach for faecal decomposition.