Tense and aspect systems in Kihangaza

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University of Dar es Salaam
One of prominent environmental problems in Eastern Africa Sub-region is discharge of untreated industrial effluent especially tannery and abattoir. These restrained by highly soluble and insoluble organic matter (Chemical Oxygen Demand (COD), Biological Oxygen Demand (BOD5)), nutrients (Nitrate (NO3-), Phosphates (P0-4)), chromium (CO and sulfur oxides which have negative and detrimental effects on aquatic life ecosystems and public health. This dissertation focused on the design of efficient and affordable pilot treatment facilities; pre-treatment (screening, sedimentation pond) and bio-process (Sequencing Batch Reactor (SBR) integrated with Constructed Wetland (CW) for these effluents. Results indicate the following results for Modjo tannery facilities: Sewer: area 0.07m2, length 10m, width 23cm and depth 23cm. Sump: area, 3.75m2, length 3.75m, width lm and depth 1.5m. Screening: area 0.52m2, length 3m, width 0.8m and depth 0.8m and screens with 15 bars. Sedimentation and equalization pond: area 40m2, length 10m, width 4m and average depth 1.5m; Pump chamber: area 4m2, length 2m, width 2m and depth 1.8m and submersible pump installed has power output of lkW at delivery head of 10m. For 2-anaerobic and 1-aerobic SBR each have diameter 4m, depth 3.3m and retention time of 24hrs. Aerobic SBR works in oxic/anoxic conditions aerated by diffusers at air rate of 33.378kg/h using blower of 1kW power for 6.5hrs and mixed by mixer for 17.5hrs at mixing discharge rate 2.53m3/s and power input 6.30kW. CW was established, area: 556m2, length 35m, width 15m, depth lm and hydraulic retention time, HRT; 7days. Kampala abattoir CW: area 65m2, length 13m, width 5m, depth 1 m and HRT; 5days. Facilities were constructed successfully, however the treatment performance was not tested because it was completed 14months; (December, 2008 to March, 2010) late to meet thesis submission period. It is recommended further studies be conducted on both Modjo Tannery and Kampala Abattoir; to evaluate the performance of integrated SBR-CW, to determine removal efficiency of parameters; BOD5, COD, PO4-, NH4+, NO3-, NO2-, to determine the amount of biogas produced in anaerobic SBRs and to install incinerator to deal with dried-sludge contained Cr+3 and sulfur oxides.
Available in print form, East Africana Collection, Dr. Wilbert Chagula Library, Class mark (THS EAF PL8230.34.C67)
Hangaza language, Bantu languages, Tense
Cosmas, C. N.(2010). Tense and aspect systems in Kihangaza, Master dissertation, University of Dar es Salaam.