Thesis and dissertation

Browse

Recent Submissions

Now showing 1 - 5 of 34
  • Item
    QUANTIFYING EMISSIONS OF VOLATILE ORGANIC COMPOUNDS AND GROUND LEVEL OZONE ON PETROLEUM FILLING STATIONS IN URBAN WEST, ZANZIBAR
    (SUZA, 2020-12) SOUD, Mohamed, Saadat
    The aim of this study was to quantify emissions of volatile organic compounds and ground level ozone on petroleum filling stations in urban west, Zanzibar. Between August and November 2019, ambient concentrations of volatile organic compounds (VOCs), and ozone were quantified from 14 petroleum filling stations in urban and west districts. These stations are allocated in urban west region Zanzibar. Using BH-4S Portable multi-gas detector, in situ measurement was conducted to quantify the concentrations of VOCs and ozone from each site twice a day (before noon and afternoon) for two separate sessions (August to September and October to November 2019). The analyzed data revealed temporary and spatial variations of measured parameters. VOCs range were 22.9 ppm and 32.3 ppm and ozone range was 4.2 ppm and 9.7 ppm for the first and second phase respectively. VOCs and ozone concentrations showed direct relationship between one another as we witnessed the good correlation (R2 = 0.625) between these two parameters. Possibly, ground level ozone could be triggered by the presence of volatile organic compounds under the presence of nitrous oxide (NOx) and sunlight. Besides that, the average VOCs levels from the selected sites ranged from 24.3 ppm at Kwerekwe3 to 47.2 ppm at Kinazini for first phase. For the second phase, average VOCs levels ranged from 38.7 ppm at Kwerekwe1 to 71.05 ppm at Kiembe Samaki. In other hand, average ozone concentration ranged from 0.6 ppm at Gulioni to 4.8 ppm at Kwerekwe1 for the first phase. While second phase average ozone concentration ranged from 4.5 ppm at Kwerekwe1 to 14.2 ppm at Kwamchina. Generally, VOCs and ozone levels at petroleum filling stations were higher compared to accepted levels provided by international, and local organizations and agencies. Moreover, during second phase, levels of measured parameters were higher than those taken from first phase, presumably to temperature variation. The most important concern is to reduce VOCs level at petrol filling stations by installation of vapour recovery system in all the stations and activating the systems at the time of gasoline discharge. This could probably help to combat the formation of ground level ozone at the stations.
  • Item
    CHEMICAL INVESTIGATION OF MARINE BROWN ALGAE FUCOIDAN COMPOSITION FROM ZANZIBAR COASTAL WATERS
    (SUZA, 2020-10) ALI, Hamad Ali
    Marine brown algae are important renewable resources with excellent sources of functional metabolites which possess several beneficial effects that have attracted great interest in functional foods, pharmaceuticals, and cosmetic applications. Three marine brown algae: Padina sp., Sargassum sp. and Turbinaria sp. were collected to chemically investigate the relative composition of fucoidan present in the algal species by hot water method. The chemical composition of the extract such as total sugar, sulphate and protein contents were determined by calorimetric method while fucoidan structural analysis were carried out using Fourier Transform Infrared – Attenuated Total Reflectance (FTIR-ATR) and Ultraviolet (Uv) spectroscopy. The yield of fucoidan has been found to vary between the species selected at which 11.5% (dry weight), 7.1% and 7.0% for Padina sp., Sargassum sp. and Turbinaria sp. respectively are reported from this study. Compositional analysis of fucoidan has revealed that Padina sp. produce higher amount of fucoidan but its sulphate content is slightly lower (21.0%) in comparison with Sargassum sp. (22.0%) while total sugar recorded is 6.46% and protein is 0.3%. Sargassum sp. produce higher total sugar (15.38%), higher sulphate content (22.0%) and lowest protein (0.1%) among the three species of marine brown algae collected. Total sugar, sulphate and protein contents in Turbinaria sp. has been found to be 6.77%, 12.00% and 0.2% respectively. FTIR spectroscopy showed a major broad band centered around 3376 cm-1 assigned to be a characteristic of O-H stretching vibration which were observed in all three species. The band appeared at 843 cm-1 suggesting to be C-O-S stretching of sulphate group. Therefore, this study has revealed that, Sargassum sp. is a rich source of Sulphated fucoidan which may be recommended for human consumption.
  • Item
    ASSESSING COMMUNITY ADAPTATION STRATEGIES TO FLOODS:
    (SUZA, 2020-12) NASSOR, Badriya Salum
    Background: Floods disasters around the world has increased for the last 20 years and affected billions of people. The same have been observed in Zanzibar which resulted to severe impacts in many parts of Urban-West Region and affected many people, threaten several lives and caused substantial economic losses. Therefore, this study intended to assess the community adaptation strategies to floods, the genesis of those strategies and the limiting factors for each adaptation strategies in flood-prone areas in Urban District in Zanzibar, Tanzania. Methodology: This was a cross sectional study design conducted in Shehia of Nyerere, Kwa Wazee and Jan’gombe. It involved 399 head of the households, 2 members from governmental and 2 members from non-governmental organizations dealing with disasters. Data was collected using interviewer administered questionnaire for heads of the households to assess their adaptation strategies and the limiting factors to adaptation strategies, while key informant interview was used to get information about the genesis of adaptation strategies and the limiting factors to adaptation strategies from the members of government and non-government organizations dealing with disasters. Results: The study revealed that majority of participants were females 231 (57.9%), age 40 and above, and most of them were non-government employees 206 (51.6%). Also the study discovered that community has been employing different adaptation strategies to reduce the floods risk at pre, during and after floods. Before flooding they use to cement floor, while during flooding moved to another place and after flooding did the structural repairs of their houses. Measures taken by the organizations include; giving early warning information through different media, waste management and construction of new drainage systems. Major factors hindering the community adaptations were; lack of resources, lack of technology and lack of social adhesion. It is suggested that the government should provide the support to the communities in order to improve their resilience against the floods. Also, the community should take upon explored adaptation opportunities available in the communities, and proposed effective and efficient future interventions.
  • Item
    ASSESSING COMMUNITY ADAPTATION STRATEGIES TO FLOODS;
    (The State University of Zanzibar, 2020-12) NASSOR, Badriya Salum
    Background: Floods disasters around the world has increased for the last 20 years and affected billions of people. The same have been observed in Zanzibar which resulted to severe impacts in many parts of Urban-West Region and affected many people, threaten several lives and caused substantial economic losses. Therefore, this study intended to assess the community adaptation strategies to floods, the genesis of those strategies and the limiting factors for each adaptation strategies in flood-prone areas in Urban District in Zanzibar, Tanzania. Methodology: This was a cross sectional study design conducted in Shehia of Nyerere, Kwa Wazee and Jan’gombe. It involved 399 head of the households, 2 members from governmental and 2 members from non-governmental organizations dealing with disasters. Data was collected using interviewer administered questionnaire for heads of the households to assess their adaptation strategies and the limiting factors to adaptation strategies, while key informant interview was used to get information about the genesis of adaptation strategies and the limiting factors to adaptation strategies from the members of government and non-government organizations dealing with disasters. Results: The study revealed that majority of participants were females 231 (57.9%), age 40 and above, and most of them were non-government employees 206 (51.6%). Also the study discovered that community has been employing different adaptation strategies to reduce the floods risk at pre, during and after floods. Before flooding they use to cement floor, while during flooding moved to another place and after flooding did the structural repairs of their houses. Measures taken by the organizations include; giving early warning information through different media, waste management and construction of new drainage systems. Major factors hindering the community adaptations were; lack of resources, lack of technology and lack of social adhesion. It is suggested that the government should provide the support to the communities in order to improve their resilience against the floods. Also, the community should take upon explored adaptation opportunities available in the communities, and proposed effective and efficient future interventions.
  • Item
    ASSESSMENT OF MANGROVE BLUE CARBON STOCKS IN NYEKE MANGROVE FOREST IN UNGUJA - ZANZIBAR
    (SUZA, 2022-12-12) DAUD, Zubeir Othman
    Blue carbon refers to carbon stored or sequestered in vegetated marinesincluding mangroves, sea grass, salt marsh and coral reef.Despite their benefits and services, blue carbon mangrove ecosystems are some of the most threatened ecosystems on the earth, they are disappearing three to five times faster than overall global forest losses, with serious ecological and socio-economic impacts. It is estimated that every year about 0.15 - 1.02 billion tons of carbon dioxide are being released from deforestation and degradation of blue carbon ecosystems, which account up to 19% of carbon emissions from global tropical deforestation. This field study was carried out to quantify the above ground and below ground blue carbon stocks of the three dominant mangroves: Avicenia marina (Mchu), Bruguiera gymnorrhiza (Msisi/Msinzi) and Rhizophora mucronata (Mkoko magondi). This study was conducted in March 2020, at Nyeke-Uzi mangrove forests in Zanzibar and employed field survey and explorative study design. It used an allometric method for biomass determination where diameter at breast height (DBH) and tree height (TH) were measured as dependent variables. Biomass were then used to calculate the carbon contents both above ground and below ground tree parties through zones. R. mucronata contributed higher value of carbon contents of 8323Mg C ha-1 (41.66%) followed by A. marinaof 5952 Mg C /ha (29.79%) and B. gymnorrhizaof 5705 Mg C /ha (28.55%). AGC was higher 12300 Mg C /ha (61.56%) than BGC 7681 Mg C /ha (38.44%). This is because carbon content is affected by size of DBH found in the upper zone contributed by Avicenia marina having greater mean value of DBH 36.2cm, max. DBH 250cm followed by 17cm (max.DBH 60cm) and 15cm (max. DBH 5cm) of R.m and B.g respectively.Lower zone contributed higher carbon content 7345 Mg C /ha (36.76%) followed by upper zone 6735 Mg C /ha (33.71%) and mid zone 5901 Mg C /ha (29.53%). This result is due to high distribution of R. mucronata with prop roots in the lower zone and lack of A. marina species. Trees with higher DBH and height had We conclude that for rising carbon stock capacity in mangrove ecosystem of Zanzibar, more conservation efforts are needed by the community including shifting to non-destructive forest demands such as bee keeping, eco-tourism, seaweed and fish farming confirmed having higher carbon contents than the rest lacking such characteristics. We conclude that for rising carbon stock capacity in mangrove ecosystem of Zanzibar, more conservation efforts are needed by the community including shifting to non-destructive forest demands such as bee keeping, eco-tourism, seaweed and fish farming so as to provide important chance for carbon stocking as well as improving blue economy