Impacts of Wood Fuel Uses on Forest Cover: The Case of Semiarid Areas in Northern Tanzania

Satellite images for the years 1987, 1997, 2002 and 2017, and questionnaire surveys were used to assess energy sources and demands as well as the impacts of wood fuel use to forest cover changes in Meru and Mwanga Districts. The major energy sources identified include cow dung cake, firewood, charcoal, liquefied petroleum gas and biogas. The total energy demands from these sources were 1400 (in Meru), 6289, 724 and 21 kg per day, respectively. The amount of biogas was not quantified since the reactors were constructed locally with no reading meter. Analysis from Landsat images showed variations in forest cover. The areas covered with forests in Meru were found to be 1510, 1723, 1612 and 1327 ha for 1987, 1997, 2002 and 2017, respectively. The changes observed in Mwanga District were 31705, 31988, 17939 and 30960 ha for 1987, 1997, 2002 and 2017, respectively. From the findings it was observed that, the ongoing use of wood fuel in semi-arid areas of Meru and Mwanga could deplete forests completely. The study concludes that charcoal and firewood consumptions are real threats to the long-term persistence of forests in Tanzania and proposes the use of renewable energy such as biogas for alleviating forest losses. Keywords: Biogas, energy sources, Satellite image

Optimization of Sedimentation Tank Coupled with Inclined Plate Settlers as a Pre-treatment for High Turbidity Water

Access to clean and safe drinking water is a challenge in most rural areas of Tanzania. Unsafe drinking water is a major cause of water-related diseases that predominantly affect people living in developing countries. In most places, water is readily available during the rainy season, but it is muddy and full of sediments. But in Karatu, regardless of the season, water is always highly turbid with suspended particles. High turbidity water is a great challenge to water treatment works as it can be hard to remove and also harbors pathogens. Because of a lack of cost-effective purifying agents, communities suffer from water scarcity and use water that is no doubt contaminated by sediment and livestock/human feces. Today there are many technologies available to treat unsafe water. However, most of such technologies are suited for use with low or no turbidity source water. Ultra- Filtration (UF) is very effective in making unsafe water safe through removal of chemical species and pathogens. UF, however, like many other treatment techniques, is limited to treating water with high turbidity. Pre-treatment is needed. The pre-treatment of high turbidity water (>1000 NTU) is a challenge that was investigated in this research. This paper describes a laboratory scale sedimentation tank coupled with Inclined Plate Settlers (IPS) tested and optimized at NM-AIST, to see if IPS can pre-treat the raw water to remove enough turbidity to make UF a feasible option. The results of this work show that IPS is not only a feasible option in pre-treating highly turbid water for the UF (˂ 50 NTU) but also a viable technology in treating water with very high turbidities to within the Tanzania drinking water standards (< 25 NTU). The design is ready for pilot testing in field environment. Keywords: High turbidity water, Sedimentation tank, Inclined Plate Settler, Ultra-Filtration

Design and Optimization of Sedimentation Tank Coupled with Inclined Plate Settlers as a Pre-Treatment for Ultra-Filtration

Access to clean and safe drinking water is difficult in most rural areas of Sub-Saharan Africa. In most places, the water is generally available during the rainy season, but it is muddy and full of sediments. But in Karatu, regardless of the season, the water is always highly turbid with suspended particles. High turbidity water is a great challenge to water treatment works as it can be hard to remove and also harbors pathogens. Because of a lack of cost-effective purifying agents, communities suffer from water scarcity or indeed drink water that is no doubt contaminated by sediment and livestock/human feces. Unsafe drinking water is a major cause of water-related diseases that predominantly affect people living in developing countries. Today there are many technologies available to treat unsafe water. However, most of such technologies are suited for use with low turbidity source water. Ultra- Filtration (UF) is one technology which is limited to treating high turbidity water. The pre-treatment of high turbidity water (>1000 NTU) is a challenge that was investigated in this research. This paper describes a laboratory scale sedimentation tank coupled with Inclined Plate Settlers (IPS) tested and optimized at Nelson Mandela African Institution of Science and Technology (NM-AIST), to see if, given the local particle sizes and distribution in the earthen dam water of Karatu, IPS can pre-treat the raw water to remove enough turbidity to make UF a feasible option. The results of this work show that IPS is not only a feasible option in pre-treating highly turbid water for the UF (˂ 50 NTU) but also a viable technology in treating water with very high turbidities to within the Tanzania drinking water standards (< 25 NTU). Keywords: High turbidity water; Sedimentation tank; Inclined Plate Settler; Ultra-Filtration; Water suppl

What Proportion Counts? Disaggregating Access to Safely Managed Sanitation in an Emerging Town in Tanzania.

Sustainable Development Goal (SDG) 6.2 sets an ambitious target of leaving no-one without adequate and equitable sanitation by 2030. The key concern is the lack of local human and financial capital to fund the collection of reliable information to monitor progress towards the goal. As a result, national and local records may be telling a different story of the proportion of safely managed sanitation that counts towards achieving the SDG. This paper unveils such inconsistency in sanitation data generated by urban authorities and proposes a simple approach for collecting reliable and verifiable information on access to safely managed sanitation. The paper is based on a study conducted in Babati Town Council in Tanzania. Using a smartphone-based survey tool, city health officers were trained to map 17,383 housing units in the town. A housing unit may comprise of two or more households. The findings show that 5% practice open defecation, while 82% of the housing units have some form of sanitation. Despite the extensive coverage, only 31% of the fecal sludge generated is safely contained, while 64% is not. This study demonstrates the possibility of using simple survey tools to collect reliable data for monitoring progress towards safely managed sanitation in the towns of global South

Social-ecological assessment of Lake Manyara basin, Tanzania: A mixed method approach.

This research article published by Elsevier Ltd., 2020The social-ecological system of the Lake Manyara basin (Northern Tanzania), a UNESCO Biosphere reserve (BR) suffers from social-economic and environmental problems due to decreasing water levels, erosion and land and water use conflicts. We propose an integrated assessment of the social-ecological interactions of the area to support future sustainable management. Within the Drivers-Pressures-State-Impact-Response (DPSIR) framework an integrated literature review and several methods of knowledge collection were combined to identify future management priorities and challenges. During focus groups with farmers and pastoralists, stakeholders confirmed the role played by land use changes as driver and pressure in the landscape, e.g. through increased erosion rates and siltation of the lake. Moreover, economic and social issues were identified as prominent factors being influenced by, or influencing these processes. These statements match the scientific literature. During participatory mapping exercises different spatial and resource allocation perceptions appeared amongst pastoralists and farmers. The multidisciplinary approach proved to be useful to acquire an integrated and comprehensive understanding of the state, challenges and opportunities of Lake Manyara BR, to feed into a decision support system in service of an integrated management plan. Our assessment suggests that improved water governance in a multi-actor approach (with a focus on distribution of benefits, rights, and a specific role of the water authorities) should be a priority for future integrated management strategies. Also, awareness raising amongst decision makers, scientists and local communities is needed to demonstrate the advantages of an integrated approach. And finally, visible and fair mechanisms to share conservation revenues should be designed in a way that local benefits can be obtained together with incentive mechanisms for co-management and conservation

Assessment of fluoride bioaccumulation potential in African Catfish (Clarias gariepinus) reared in fluoride rich water

Fluoride bioaccumulation in fish poses a significant impact on their growth, survival and consequently to upper trophic levels. Few studies have reported the impacts of high fluoride concentrations and their accumulation potential to catfish in African settings. A 60-day catfish cultivation was conducted at Ngarenanyuki ward and the Nelson Mandela African Institution of Science and Technology (NM-AIST) in Arusha, Tanzania to determine fluoride bioaccumulation and its impacts to catfish growth and survival. Juvenile catfish were exposed to 36 mg F–/L pond water and synthetic water containing fluoride (NaF) concentrations of 5, 15, 36 and 45 mg/L in aquaria set at NM-AIST laboratory. Fluoride concentrations in fish tissues were analysed by ion-selective electrode. Fish survival rate was greater than 90% in ≤ 36 mg/L fluoride levels compared to 65.8% in 45 mg F–/L aquarium. Significant fluoride bioaccumulation was observed in fish bones (222.00 mg/kg, dry weight), gills (177.4 mg/kg), skin (9 mg/kg) and low amount in fillets (1.467 mg/kg). Fluoride bioaccumulation significantly rose with fluoride levels increase and exposure time (p = 0.000). The study concludes that high fluoride occurrence and its increased exposure time increases fluoride bioaccumulation in African catfish. Therefore, growing catfish in water containing ≥ 45 mg F–/L requires defluoridation process. Keywords: African catfish, Aquarium, Fluoride bioaccumulation, Growth performanc

Fluoride Variations in Rivers on the Slopes of Mount Meru in Tanzania

This study reports the variations of fluoride ions in rivers on the slopes of Mount Meru in the northern part of Tanzania. More than 318 water samples were collected from Temi, Nduruma, Tengeru, and Maji ya Chai Rivers in both wet (mid-March and April) and dry (August) seasons. The samples were analyzed for fluoride levels using Ion Selective Electrode (ISE). The minimum and maximum average fluoride levels in the wet season were 0.24±0.03 mg/l and 65.20±0.03 mg/l, respectively, whereas the average lowest and highest levels in the dry season were 1.02±0.02 mg/l and 69.01±0.03 mg/l, respectively. Tengeru River had the lowest fluoride levels in both seasons, whereas Maji ya Chai recorded the highest fluoride levels in both seasons. The headwater of all rivers with the exception of Maji ya Chai met the World Health Organization’s (WHO) maximum acceptable fluoride levels of 1.50 mg/l and the downstream environment qualified for Tanzania Bureau of Standards (TBS) maximum permissible fluoride concentration in drinking water of 4.00 mg/l. Also, the laboratory experiments showed that fluoride containing rocks exposed to pH above 7.6 display high leaching of F− in solution which gradually increased with the increase in pH, indicating that dissolution of fluoride in water is a function of pH

Data from the batch adsorption of ciprofloxacin and lamivudine from synthetic solution using jamun seed (Syzygium cumini) biochar: Response surface methodology (RSM) optimization

This dataset expresses the experimental data on the batch adsorption of ciprofloxacin and lamivudine from synthetic solution using jamun seed (JS) (Syzygium cumini) biochar. Independent variables including concentration of pollutants (10-500 ppm), contact time (30–300 min), adsorbent dosage (1-1000 mg), pH (1-14) and adsorbent calcination temperature (250,300, 600 and 750 °C) were studied and optimized using Response Surface Methodology (RSM). Empirical models were developed to predict the maximum removal efficiency of ciprofloxacin and lamivudine, and the results were compared with the experimental data. The removal of polutants was more influenced by concentration, followed by adsorbent dosagage, pH, and contact time and the maximum removal reached 90%