Includes bibliographical references and appendices

Novel technologies to convert faecal waste into valuable nutrients provide a win-win
situation in enhancing the closed sanitation loop and providing safe sanitation. In this
study, laboratory scale experiments were set to examine the treatment of organic matter
{faecal matter (FM) and kitchen waste (KW)} using black soldier fly larvae (BSFL). The
study focused on determination of chemical composition of feeding substrates, gross
nutrients in BSFL and mass balance during treatment process. Using each of the feed
substrates in triplicate, treatments were set up in rectangular plastic containers (18 by 9 by
6 cm). In each container, 500 g of feed substrates were added and 3 g of 6-day old larvae
introduced. Samples of BSFL and feed substrate were drawn at two days interval and
prepared for nutrient analysis. In triplicate, ten larvae were randomly picked after two days
from each feeding containers to monitor the larval weight gain. The experiments were
monitored to 50% larval maturity (turning into prepupae). The larval developmental time
to 50% pupation, survival rate (SR), waste reduction rates (WR), prepupal yield,
bioconversion rate (BCR), feed conversion rate (FCR), and efficiency of digested feed
(ECD) were monitored at the end of the experiments for mass balance process. The
chemical composition of both substrates varied significantly across the days (p>0.0.000).
The feed nutritional value was 29.21±0.06% and 17.42±0.0.09%, 12.50±0.00% and
20.01±0.00%, 0.91±0.16µg/ml and 1.22±2.82E-15µg/ml of protein, fat, and carbohydrate
content from faecal and kitchen waste respectively which were adequate for BSF growth
and development. The initial moisture content ranged from 73.83±3.40% to 77.14±0.16%
with pH values of 6.27 and 3.09 from faecal and kitchen waste respectively. The larval
development time was 22 days on both feed substrate. The final nutrient composition of
BSF pupa was 34.90% and 34.55% (protein); 41.61% and 36.64% (fat), ash content
18.33% and 12.16% on faecal and kitchen waste respectively. Mass balance determination
had average prepupal yield of 70.43±0.02g and 56.77±0.01g, ECD of 17.63±0.01% and
12.05±0.00%, FCR of 4.67% and 7.30% from faecal waste and kitchen waste respectively.
From the study findings, both substrates contained nutrients palatable for BSF survival
and development as larvae survived well. The findings show the potential of using BSF
larvae technology to valorize faecal and kitchen waste and produce larval biomass rich in
proteins and fats thus enhancing the reuse section on the sanitation value chain to promote
closed loop economy. By implementing the technology, occurrence of open dumping and
faecal contamination could be reduced. The study recommends large scale treatment of
faecal and kitchen waste as well as co-digestion of different organic waste to provide
adequate nutrients for larval performance and greater treatment efficiency
Keywords: Closed loop sanitation, Faecal waste, Kitchen waste, Mass balance, BSFL