Browsing by Author "Kihila, Jacob"

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Development of a cost-benefit analysis approach for water reuse in irrigation
(Science Publishing Group, 2014-10-10) Kihila, Jacob; Mtei, Kelvin; Njau, Karoli
Water reuse is one of the alternatives to counteract the already experienced water shortages. However water reuse as any other investment is associated with costs. This article looks at water reuse for irrigation as one of the areas that has recently gained attention. However, water reuse requires a prior installation of wastewater treatment and the irrigation systems of which all requires financial resources. Analysis of the costs and benefits of water reuse remains one of the key tools for decision making. Unfortunately there has been no universal way for doing cost benefit analysis that can fit all reuse applications and the local settings. The objective of this study was to customize the existing water reuse cost benefit analysis methods and develop cost benefit analysis for water reuse in irrigation. The net benefit value approach was studied, examined and modified to incorporate all the relevant cost items and benefits associated with water reuse in irrigation. Based on the approach developed a discussion have been made whereby it was evident that the main cost elements for water reuse in irrigation are those associated with land for installations, the treatment plant and the irrigation systems involving their installations, operation and maintenance. On the other hand it has been shown that the main elements for benefits are related to natural resources recovered, improved agricultural production and the environmental benefits.
A review of the challenges and opportunities for water reuse in irrigation with a focus on its prospects in Tanzania
(Int. J. Environmental Engineering, 2015) Kihila, Jacob; Mtei, Kelvin; Njau, Karoli
Water reuse is one of the potential ways to complement the existing portable water sources. Its adoption is becoming of interest due to water shortages in many parts of the world. Its implementation is supported by several benefits though it has challenges as well. This paper provides a review of practice of the water reuse for irrigation in the world and focuses on its potentiality in Tanzania with a highlight on the water supply and wastewater treatment situation in the country. The challenges that need to be addressed, the benefits expected and global wastewater treatment options, capital and operation costs as well as the cost benefit analysis have been pointed out. Some arguments to justify a shift to water reuse in irrigation has been given. Lastly, it has been shown that full implementation of water reuse will require among other things, proper defined policy and institutional framework, clear guidelines as well as more research and investment on wastewater treatment.
Wastewater treatment for reuse in urban agriculture; the case of Moshi Municipality, Tanzania
(Pergamon, 2014-01-01) Kihila, Jacob; Mtei, Kelvin; Njau, Karoli
Urban 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.