Browsing by Author "Katima, J.H.Y."

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    Evaluation of pollution loading into Msimbazi river by rapid assessment and direct measurement methods
    (University of Dar es Salaam, 2018) Katima, J.H.Y.; Mbele, H.O.; Ntalika, J.W.
    This paper assesses the suitability of Rapid Assessment (RA) methodology as 4 tool for making an environmental pollution inventory in data poor situation. The W4 method was applied to estimate Biological Orygen Demand (BOD), nitrogen an phosphorous loading into the Msimbazi River in Dar es salaam, Tanzania. The Pree/Measurement (DM) was done to validate the results obtained from RA. The methodologis based on estimating waste loads from function variables such as production rale. population, etc. and pollution intensities from domestic, industry and agricultural sources. The incorporation ofpenetration factors for waste loads reduction refines the assessmen/procedure. The RA results show that domestic source releases 7600, 390 and 3200 tons/year of BOD, Phosphorous and Nitrogen respectively. Industrial activities in the area release BOD loading of 2500 tons/year
  • Thumbnail Image
    Item
    Pulping sisal fibres: effects of chemical concentration, na2so3/na2co3 ratio and fiber to chemical ratio
    (University of Dar es Salaam, 1994) Katima, J.H.Y.; Halfani, M.R.; Ntalikwa, J.W.
    This paper reports on pulping of hard fibres extracted from the leaves of agave sisalana using sodium sulphite buffered with sodium carbonate as pulping chemical. The cooking was carried out at I68C for a cooking period of 6 hours, with varying chemical concentration, sodium sulphite to sodium carbonate ratio and fibre to chemical ratio. The results show that both the pulp yield and pulp viscovity decrease with increasing chemical concentration, whereas Kappa number of pulp decreases to a limit of about 16.45. Brightness increases significantly with an increase in the ratio of Na3SO/Na2CO3. The pulp yield obtained indicated the following maximum strength indices: tensile index: 75.60/Nm/gJ, burst index: 6.05/kPa. m2/g/and tear index: 19.30/Nm2/kg). These values are higher than those reported for bleached pine kraft pulp; that is tensile index: 50.52/Nm/g), burst index: 5.77/kPam2/g/and tear index: 18.91/Nm2/kg) with a brightness of 81.0% ISO. These make sisal a promising candidate for non-wood pulping process.