| dc.description.abstract | Available data suggests that only 8% of the wastewater generated is treated in low income
countries. This implies that the biggest population is not connected to the sewerage system
despite the existence of sewerage treatment plants. In 2014, the number of active sewers
connections to the Kampala sewerage network was estimated at 8,359 bringing in a maximum
dry weather flow of 14,500m3/day. With these insufficient connections to the Kampala sewerage
network, the new Wastewater Treatment Plant (WWTP) in Bugolobi will not be able to achieve
the design flow of 45,000m3/day. Therefore, treatment of the available wastewater will not yield
the required sludge of 19,119kgDS/day for anaerobic digestion to produce the desired biogas to
run the plant. This therefore poses a challenge to the new WWTP to find means of optimizing
biogas production through co-digestion of the available sludge with additives like cow dung,
market waste or water hyacinths in appropriate mix ratios.
The aim of the study was to compare the performance of various substrates in co digestion with
wastewater sludge generated at Bugolobi Sewage treatment plant, Kampala, Uganda as a means
of enhancing biogas production from the sludge.
A study was conducted on wastewater from Bugolobi Sewage Treatment Plant (STP) co-digested
with market waste, cow dung and water hyacinth in different proportions. The study was done
using laboratory scale serum bottles at mesophilic temperature and sludge retention time of 30
days. Results from the study showed that co-digestion of wastewater with cow dung produced
most bio-gas with an increase by a factor of 3.7 followed by co digestion of wastewater and
market waste. Digesters containing all substrates ceased gas production at 8 days due to
acidification as a result of high organic loading.
In conclusion, to improve bio-gas yield from wastewater sludge, cow dung should be co-digested
with wastewater sludge due to higher bio-gas yield and minimum pretreatment required as
compared to the other substrates. | en_US |
