Wastewater treatment for reuse in urban agriculture; the case of Moshi Municipality, Tanzania

This research article was published by Pergamon in 2014Urban agriculture is practiced by dwellers as an adaptive response to improve their food security, household income, create informal employment and diversify their livelihood through sales of surplus produce or savings. People in many cities, who practice urban agriculture, are in most cases unemployed and poor and are faced with water shortages to irrigate their crops. But treated wastewater can offer both water and nutrients needed for crop growth partly covering the water shortage already experienced. Therefore in this case, wastewater reuse becomes one of the important alternative ways to provide water for irrigation. The objective of this study was to monitor the effluent quality of the waste stabilization pond (WSP) and a combined WSP-constructed wetland (WSP-CW) treatment systems, assess its suitability for irrigation purposes and understand the public perception on the use of the treated effluent for agricultural production. This paper brings out the experience of the Moshi urban water authority in wastewater treatment and reuse for irrigation purposes. It looks on the quality of effluent from the two systems under their current operational regime and deduces the public health and socio economic implications. The results indicates the recorded TDS mean values of 587 mg/L and 627 mg/L, Nitrate–Nitrogen values of 9.19 mg/L and 2.35 mg/L, Fecal Coliform values of 1000 counts per 100 mL and 4626 counts per 100 mL, COD values of 159 mg O2/L and 149 mg O2/L for the WSP and WSP-CW effluents respectively. From the findings it has been shown that the treated effluent is suitable for restricted irrigation. It has also been shown that when improperly practiced, the use of the effluent is associated with public health risk to the workers who handle it, but despite this fact there is still some positive social economic implications. The community members who practice irrigated agriculture using the effluent as irrigation water have positive attitude on its use. The findings from this case study, is considered as an important learning in establishing an optimal wastewater treatment configuration to render suitable effluent for irrigation purposes

Prospective Bioactive Compounds from Vernonia amygdalina, Lippia javanica, Dysphania ambrosioides and Tithonia diversifolia in Controlling Legume Insect Pests

This research article was published by Scientific Research Publishing in 2014Synthetic insecticides are widely known to control insect pest, but due to high operational cost, environmental pollution, toxicity to humans, harmful effect on non-target organisms and the de velopment of insect resistance to this products, have created the need for developing alternative such as those involving the use of botanical pesticides to control insect pest. Bioactive compounds derived from plant could be an alternative source for insect pest control because they constitute a rich source of natural chemicals. This review aims to explore the potential of plant bioactive com pounds from Vernonia amygdalina, Lippia javanica, Dysphania ambrosioides and Tithonia diversi folia as a low-cost, safe and environmentally friendly means of controlling insect pests in legum

Extrapolations on the Use of Rhizobium Inoculants Supplemented with Phosphorus (P) and Potassium (K) on Growth and Nutrition of Legumes

This research article was published by Scientific Research Publishing in 2014Land scarcity and poor farming management practices has resulted in to intensive agriculture which rendered most of the soil in sub Saharan Africa depleted in essential plant nutrients. High prices of chemical fertilizer are crucial bottleneck toward increasing production of legumes and other food crops in most countries found in sub-Saharan Africa. Nitrogen, phosphorus and potassium are among the most limiting nutrients for plant growth as they play different but crucial roles in the plant physiological processes. These macronutrients are fundamental components of cell building blocks including genes and chromosomes. This review intend to show the vital roles played by rhizobial inoculants supplemented with phosphorus and potassium in enhancing growth, yield, photosynthesis, nodulation, nutrient uptake and nitrogen fixation of legumes

Cattle dung production, management and utilization practices in the smallholding dairy farming systems of East Africa: A situational analysis in Lushoto District, Tanzani

This research articles was published in the Journal of Biodiversity and Environmental Sciences Volume 12, No. 4, p. 84-95, 2018This focus review aims to update the dung and manure production, management and utilization in the East African countries and its associated challenges particularly in the case of Lushoto district, in northern Tanzania. Attention and efforts are continuously being made to promote the use of cattle dung though the challenges still exist. Majority of smallholder farmers in the East Africa poorly manage cattle dung such that its quality is impaired. Such practices include exposing the dung uncovered in a heap and applying directly to the crops. A survey conducted at Lushoto district in the smallholder dairy farmers observed poor management from collection of dung, processing or storage to utilization causing losses of potential nutrients when it’s used as manure. Additionally, the knowledge on other uses of cow dung such as for biogas production is not adequately known. This review, therefore, revealed the need for training farmers on issues related to dung management and utilization such as the nutrient recycling at the farm scale. Cattle dung has been for a long time used as manure in agricultural production and recommendations especially on the applications and users have been generalized to a wide range of areas. There is a need to establish area specific recommendation on dung management from production to the final use. For sustainability of the knowledge, readable materials, an appropriate intervention of biogas plant, manure storage (shade structure) and decomposition process that will create awareness from production to farm application are require

Investigating Cutoff Technique for Improved Water Saving and Productivity in Furrow Irrigation System

This research article was published by Journal of Irrigation and Drainage Engineering in 2021The cutoff technique has not been adequately investigated despite being the most practiced among smallholder farmers. This study aimed at scenarios of improving water application efficiency, distribution uniformity, and productivity for the technique. Three cutoff treatments where water supply was stopped with the advance phases reaching 75%, 80%, and 90% of furrow length were investigated with eight irrigation events. Mean application efficiencies with significant difference (P0.05). The results demonstrated the 75% cutoff has the potential of saving water of up to 26% without compromising water productivity. It is recommended therefore that the 75% cutoff position of water supply be promoted among the smallholder farmers and that research studies should now intensify for less than 75% cutoff

A survey of irrigation water and soil quality that likely impacts paddy rice yields in Kilimanjaro, Tanzania

This research article published by Springer Nature Switzerland AG., 2021In this study, the impacts of irrigation water quality and soil characteristics on paddy rice yields were investigated. Standard spectroscopy and spectrometry methods were used to analyze irrigation water and irrigated soil samples. The irrigation water had sodium adsorption ratio (SAR) values ranging from 0 to 3. The corresponding electrical conductivity (EC) values were between 0.2 and 0.7 dS/m and accounted for 14% of all samples—posing slight to moderate infltration problem. Neither Na+ nor Cl− levels were high enough to cause toxicity problems in the irrigation water. For B, 54% of the samples were found to have moderate toxicity whereas~14% of the samples indicated severe B toxicity in the irrigation water. For bicarbonate, about 86 and 14% of the irrigation water indicated slight-to-moderate and severe potential det rimental efect to plant growth, respectively. All trace elements in the irrigation water were too low to cause any harmful efect. Although soil EC, organic carbon (OC), and pH indicated favorable level, there were high standard deviation (SD) values in soil Fe and Zn. The mean value of Fe in soils was 19.8 mg/kg, indicating signs of Fe-defciency. High SD values were also found in the total N (TN) content of the studied soils. Furthermore, a low soil K content was observed in the analyzed soil samples. Appropriate fertilizer application for improving nutrient defciencies in the study area is highly recommended. Furthermore, on-farm management practices need to be guided by scientifc fndings from the present as well as other studies

Yield and Fiscal Benefits of Rhizobium Inoculation Supplemented with Phosphorus (P) and Potassium (K) in Climbing Beans (Phaseolus vulgaris L.) Grown in Northern Tanzania

This research article was published by Scientific Research Publishing in 2015Both field and green house experiments were intended to investigate and evaluate the outcome of rhizobial inoculation supplemented with P and K on climbing beans production in northern Tan zania. The results obtained indicated that, inoculation using Rhizobium inoculants supplemented with fertilizers significantly (p ≤ 0.001) improved both vegetative and yield parameters of climb ing beans varieties compared with control treatment. The economic analysis in rhizobium alone revealed a profit of US$2350 compared with control treatment with US$ 1558 profit, which was finally reflected in higher percentage increase over control and higher marginal rate of return (MRR). Thus, the use of Rhizobium inoculants supplemented with P and K increased climbing beans yield and the economic analysis performed based on total revenue and variable costs re flected an improvement in economic well being of a small hold farmer of northern Tanza

Non-competitive and competitive detoxification of As (III) ions from single and binary biosorption systems and biosorbent regeneration

This research article was published by Springer Nature Switzerland AG. in 2023The quantity of studies reporting on single-metal sorption systems is increasing every day while the elimination of heavy metals in binary and multisolute systems is seldom reported. Therefore, the biosorption and desorption of arsenic from single and binary systems on hybrid granular activated carbon have been investigated using the batch technique. The hybrid granular activated carbon was characterized using Fourier transform infrared spectrometer and Brunauer–Emmett–Teller, and the results showed that the biosorbent surface characteristics could facilitate arsenic removal from the non- and competitive biosorption media. The main biosorption mechanisms of arsenic on the biosorbent involved surface complexation, electrostatic attraction, and replacement of hydroxyl groups. Furthermore, the effective elimination of arsenic was discovered to be reliant on the sorbent’s physicochemical properties as well as all the studied independent biosorption factors. The equilibrium sorption data of both the single and binary systems were best explained by the Langmuir and pseudo-second-order models, indicating the mechanism of arsenic biosorption was mainly chemisorption. The Langmuir maximum monolayer sorption capacities of the biosorbent were 205.76 and 153.09 mg/g for the single and binary systems, respectively. While the evaluated thermodynamic parameters suggest that the biosorption removal of arsenic from both sorption systems was spontaneous and endothermic with increasing randomness at the liquid–solid interface, the successive biosorption–desorption studies indicated that the exhausted biosorbent can be renewed without a substantial deterioration in its uptake capacity even after the seventh regeneration cycle. This indicates that the biosorbent has the economic potential to be used repeatedly in arsenic species sequestration from wastewater

Modeling and optimization of trivalent arsenic removal from wastewater using activated carbon produced from maize plant biomass: a multivariate experimental design approach

This research article was published by Springer Nature Limited in 2023Globally, both industrialized and developing nations struggle with the issue of water pollution due to heavy metals. Human life depends on water, and when it is contaminated with dangerous heavy metals like arsenic, people’s health suffers. The interactive influence of three independent sorption processes variables such as bio-adsorbent dosage (0.50–3.00 g/L), contact time (40.00–90.00 min), and initial concentration (10.00–30.00 mg/L) on the modeling and optimization of trivalent arsenic removal from wastewater was studied in a batch mode using multivariate experimental design. The quadratic models provided accurate predictions for the response variables with high coefficients of correlation of 0.9984 and 0.9994 for removal and uptake rates, respectively. The developed models were accurate and exhibited a remarkable correlation between the observed and projected data according to the diagnostic test analyses. Through the analysis of variance, all the studied adsorption factors were statistically significant (p-values < 0.0001) with initial concentration and bio-adsorbent dosage producing the main interactive effect on the percentage removal and adsorption capacity with F-values of 146.05 and 264.65, respectively. The optimum operating conditions attained were 90.00 min contact time, 0.50 g/L bio-adsorbent dosage, and an initial concentration of 10.00 mg/L, which gave arsenic maximum removal and uptake efficiencies of 93.14% and 7.04 mg/g, correspondingly with the desirability of 0.844. Confirmative tests were conducted under the optimized conditions to validate the accuracy of the models in which a maximum removal efficacy of 94.33% and adsorption capacity of 7.15 mg/g were achieved. The applicability of the bio-adsorbent in the adsorption of arsenic in textile industrial wastewater was also tested and the bio-adsorbent could competitively decontaminate over 99% of arsenic species from the wastewater

Radon Mass Exhalation Rates of Selected Building Materials in Tanzania

This study aimed at determining the mass radon exhalation rate of Tanzania Portland cements and their raw materials for assessment of the radiological hazards due to use of those materials in residential construction. The radon mass exhalation rate was measured by closed chamber coupled with the Pylon AB5 Ô and varied from 0.3 to 13 %. The estimated indoor radon concentrations and annual effective dose for tightly closed standard room were within the safe limits of radon potential health hazards of 600 Bq m-3 for dwellings and 1500 Bq m-3 for workplaces recommended by International Commission on Radiological Protection (ICRP). Key words. Building materials; Radon mass exhalation rate; Annual effective dose; Radiological hazard; Tanzani