Publications

Alcohol distilleries produce effluents which are strongly acidic, have high Chemical Oxygen Demand (COD) and Biochemical Oxygen Demand (BOD), contain strong odour and are dark brown in colour. They cause detrimental environmental effects if they are freely disposed off to the environment. Adopted anaerobic treatment techniques with associated biogas generation have not proved to be very efficient on high strength distillery effluents as substrates. The improvement on mean product yield, effluent stabilization and sterile air tolerance was explored through microbial immobilization on activated natural zeolite and calcium alginate supports. Three experimental set-ups were performed with the first acting as a control and having no support material whereas the second and third having microbial system immobilized unto activated natural zeolite and calcium alginate supports respectively. At the marginal organic loading of 75 kg/m3 (corresponding to undiluted waste water), the unsupported system showed a low yield of 2.1 X 10-3 m3/kg CODt in biogas, whereas the calcium alginate system registered the highest yield of 84.5 X 10-3 m3/kg CODt . Activated natural zeolite system on the other hand showed a yield of 43.6 X 10-3 m3/kg CODt. Based on the effluent stabilization over the same initial marginal organic loading, activated natural zeolite system demonstrated the highest degree in effluent stabilization of 44.0 % as opposed to the unsupported and the calcium alginate system that registered 24.0 % and 41.3 % respectively. Finally, activated natural zeolite supported system showed the longest tolerance to sterile air exposures of 90 minutes. The unsupported system registered a tolerance of 30 minutes whereas the calcium alginate system demonstrated 60 minutes of oxygen tolerance.

The objective of this study was to describe the physical, social, and psychological initiation practices of street connected children and youths, in Eldoret, western Kenya.

Increasing use of pesticides threatens the quality of groundwater with contamination. The objective of the study
was to assess the use of integrated pest management (IPM) in reducing the risks of groundwater contamination
in Lake Naivasha basin, Kenya. Interviewer administered questionnaires were used to collect data on types and
quantities of pesticides used; and other methods used to control weeds, pests and plant diseases. The results
showed that 141 pesticides were used in the basin and that 75% of farms were applying pesticides in high
quantities. All the farms were also using IPM where pesticides and other conservative means were applied.
Majority of farms (62.5%) reported average harvest when IPM methods were used. It was concluded that IPM
program around Lake Naivasha is still in its initial stages and in transition from intensive pesticide use. The
risk of groundwater contamination in the lake basin is therefore still high.