Civil and Water Engineering Publications

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Civil and Water Engineering Publications

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    Microbial Removal of Pb(II) Using an Upflow Anaerobic Sludge Blanket (UASB) Reactor
    (MDPI Catalysts, 2021-04-19) Chimhundi, J.; Hörstmann, C.; Chirwa, E.M.; Brink, H.G.
    The main objective of this study was to achieve the continuous biorecovery and bioreduction of Pb(II) using an industrially obtained consortia as a biocatalyst. An upflow anaerobic sludge blanket reactor was used in the treatment process. The bioremediation technique that was applied made use of a yeast extract as the microbial substrate and Pb(NO3)2 as the source of Pb(II). The UASB reactor exhibited removal efficiencies of between 90 and 100% for the inlet Pb concentrations from 80 to 2000 ppm and a maximum removal rate of 1948.4 mg/(L·d) was measured. XRD and XPS analyses of the precipitate revealed the presence of Pb0, PbO, PbS and PbSO4 . Supporting experimental work carried out included growth measurements, pH, oxidation–reduction potentials and nitrate levels.
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    Performance Based Water Loss Management for Gweru, Zimbabwe
    (2017) Makaya, E.
    Different water utilities use different performance indicators to assess their performance. Although these indicators are peculiar to particular situations, it is paramount that each indicator is applied consistently among utilities as this is good for benchmarking purposes. Besides being well documented, performance indicators have not been well reviewed from the perspective of developing countries. Furthermore, there is limited understanding of the application of performance indicators among developing countries. Therefore this paper reviewed performance indicators for physical water loss management. The African Development Bank self-assessment matrix was applied to the City of Gweru, Zimbabwe. Furthermore, the infrastructure leakage index was used to assess the performance of the water utility. The self-assessment approach showed a 62% level of implementation of NRW strategies by the city. This means that the city was poorly managing its non-revenue water. The city had an infrastructure leakage index of 9.7. This index is in Category C of the International Water Association physical loss matrix meaning that the city was managing its non-revenue water poorly. Therefore the city must be proactive in the management of its physical water losses as well as maintain its infrastructure consistently.
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    Research Funding Needs for African Engineers: Challenges and Perceptions
    (2017) Makaya, E.
    Africa and sub-Saharan Africa in particular, with the exception of South Africa, have lately lagged behind in postgraduate research, an issue attributed to lack of research funding for engineering sciences. This paper investigated the funding needs of engineering sciences in Africa. Specifically, it established the funding needs of African engineering sciences, factors affecting higher learning institutions in securing research funding and assessed the prevalent engineering research needs for Africa. Key informants to this paper were postdoctoral candidates drawn from Cameroon, Ethiopia, Ivory Coast, Kenya, Nigeria, Tanzania, Uganda and Zimbabwe. Through a questionnaire survey, the study found out that Africa has the capacity to carry out high profile engineering researches but the funding needs are not fully met resulting in frustration, whose ripple effects culminate in brain drain. Institutional frameworks in many African countries have been found not favouring engineering sciences. Although efforts are being made, as evidenced by increase in scientific publications, the growth of Engineering Sciences lags behind other disciplines. Thus, the international community of research funders should forge partnerships and collaborations with engineering institutions in Africa for availing and putting to good use research funding.
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    Impacts of Solid Waste Management Practices on Environment and Public Health: A Case of Bahawalpur City, Pakistan
    (2016) Mohsin, M.; Chinyama, A.
    Safe and secure disposal of solid waste is now becoming a major issue for most of developing countries with accelerating urbanization and increasing pressure of populations. A study was conducted in Bahawalpur City; Pakistan. The main objective of the study was to investigate the sources and impacts of solid waste management practices on the surrounding environment and public health. This was achieved by specifically identifying the sources and types of solid waste in the city by identifying the different solid waste management practices and their impacts on the environment and human health. Data about solid waste generation, collection, disposal and their impacts on human health and environment was collected in Model Town C using a structured questionnaire from 80 randomly sampled respondents as well as by field observations. Secondary data from institutional records was also collected. Statistical analysis in the form of descriptive statistics and chi-square test were applied to the data. It was found that the environment in study area was highly polluted with open dumping of solid waste in open spaces and vacant plots. Households contributed the most solid waste generation and open dumping. The solid waste generated at household level consisted of organic waste, plastics and polythene bags. Institutionally, Tehsil Municipal Administration (TMA) and later Bahawalpur Waste Management Company (BWMC) were found to be responsible for solid waste management in the city but the overall situation is not satisfactory. The impacts of poor solid waste management practices were found to be: land degradation, creation of breeding grounds for disease carrying vectors such as mosquitoes, rats, rodents, decrease in land values; and different severe diseases. Furthermore, it was found by statistical analysis, that there was a significant relationship between the poor solid waste management practices and environmental and health problems faced by the community
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    Predictive Leakage Estimation using the Cumulative Minimum Night Flow Approach
    (2017) Makaya, E
    Several methods have been used in estimating leakages. Although the minimum night flow analysis method has been widely used in leakage estimation, the cumulative minimum night flow method is one method that can yield comparatively good leakage estimates. This paper applies the cumulative minimum night flow method to estimate water leakage in a water distribution system. The cumulative minimum night flow method develops a model from empirical night flows which is used to estimate mean minimum night flows and hence estimate leakages. The result was compared with the South Africa minimum night flow analysis methodology. It was found out that the model developed from the cumulative minimum night flow method yielded good result, (R2 =0.9998). Thus, the cumulative minimum night flow method could be relied on in predicting leakage estimates in water distribution systems. Furthermore, the model could be used in other locations other than that described in this paper.