9 research outputs found
Water services with independent providers in peri-urban Maputo: Challenges and opportunities for long-term development
Water service delivery to most residents of peri-urban areas of greater Maputo depends largely on alternative service providers, mostly in the form of small-scale independent providers (SSIPs). This paper discusses the present and long-term challenges facing SSIPs in supplying quality water of sufficient quantity in peri-urban Maputo and possible human health risks associated with the consumption of water provided by SSIPs. Extensive water sampling and analyses were conducted to evaluate the physicochemical and bacteriological quality of water provided by independent providers and the associated human health risks. Borehole pumping tests, the results of which were interpreted using the graphical method of Jacob, were used to evaluate the regional aquifer potential, the long-term impacts of its exploitation and the aquifer vulnerability to external contamination. From the results of borehole pumping tests it was concluded that the present yields are in average 33% lower than estimated safe yields and that larger than present yields therefore can be exploited. The aquifer vulnerability to external contamination (e.g. by E. coli and nitrates) is low, mainly because of low hydraulic loads and the existence of a rather thick (10 to 30 m) sandy unsaturated stratum where bacteria die-off and biological denitrification probably occurs. However, the aquifer vulnerability to sea sea-water intrusion is high. Currently, the health risks posed to consumers relying on services provided by SSIPs are small; even so, 13 out of 35 controlled boreholes had either total coliform or faecal coliform levels higher than the WHO standard. In the long run SSIPs may face more serious water quality problems due either to over-exploitation of the aquifer system or increased hydraulic loads resulting from increased population density.Keywords: water supply services, peri-urban areas, small-scale independent providers, water quality, public healt
Challenges and Opportunities For Safe Water Supply in Mozambique
In Mozambique, despite considerable investments in the promotion of drinking water supplies, the access to quality water of sufficient quantity for the majority of people is still far from optimal. Current official figures report that nearly half of the country´s population and about 45 per cent of urban residents do not have access to safe water. As a result of poor performance or absence of public water services, in most areas, informal private operators supply water to the most of underserved populations. Management of drinking water quality is inadequate and is affected by limitations at production and distribution level. This research included an analysis of drinking water supply aspects of Mozambique with the view to contribute to the understanding of the factors affecting present drinking water supply and the challenges facing the water governance sector in developing and maintaining sustainable drinking water supplies. Emphasis was put on identifying critical factors affecting production and management of drinking water quality. The analysis of water quality aspects shown that present limitations in water safety and water quality are due mainly to lack of adequate treatment, inadequate management of distribution and lack of knowledge among operators. The quality of water sources used for drinking water production is very similar to that of many other parts of the world and the methods used for water treatment are, suited for production of excellent treated water quality. However, poor knowledge and inefficient operation of treatment processes causes drinking water production to be ineffective. Methods of improving drinking water treatment were also investigated. For reasons of sustainability, low cost treatment methods were selected. Pre-treatment with up-flow roughing filtration and use of natural coagulants (Moringa Oleifera) for water treatment were the methods tested. The results proven that if properly incorporated in the drinking water treatment strategy of the country, these methods can provide a viable and sustainable alternative for improved drinking water production. Service quality aspects of informal private operators were also analysed. It was concluded that they provide a reliable alternative for access and for expansion of service delivery to areas lacking piped water supply. It was also concluded that present human health risks for consumers relying on these services are comparable to that of formal water supplies. However, the lack of an inclusive regulatory framework to this type of service providers limits the possibilities for regulation of their activities. Therefore, regulation aspects around formal and informal service providers formed part of the research and a proposal for expanding the existing regulatory framework was presented. Licensing and regulatory functions needed are presented. The main conclusion of this study is that two major factors affect drinking water supply in Mozambique specifically; limited service coverage and; limitations in water safety and water quality caused by lack of adequate treatment, poor management of water distribution and lack of knowledge among operators. The main contribution of this study is to the water governance sector of Mozambique and it refers to the various possibilities offered by methods tested during this study, for sustainable improvement of drinking water production. In addition, the findings of the discussion of the drinking water supply situation looking not only at quantity but also at quality aspects of service delivery as was done in this study, will hopefully help the sector redefine its strategy of addressing drinking water supply in Mozambique
Assessment of coal mine water in Moatize by static and leaching tests
Acid mine drainage (AMD) is one of the most serious environmental problems in mining worldwide. One of the largest unexploited coal basins in the world is located in Moatize. It contains about 23 billion metric tonnes of coal. The coal mining there is done in riparian sections of the Zambezi River basin, making it particularly vulnerable to pollution. Much of the coal waste is produced by a number of multinational mining companies operating in the area. Accordingly, it was of clear interest to investigate the possibility that AMD was being generated there. Coal waste and pit water were collected randomly from different piles and pits in two mines in Moatize. Both static and kinetic tests were performed. It was found that AMD could be generated in one of the two mines that were studied. The mine drainage obtained from both coal mines was found to be of neutral pH and to have a high content of sulfates, calcium, magnesium, and manganese
Bioadsorbents of heavy metals from coal mines area in Mozambique
Mozambique is one of the largest coal exporters in Africa. Usually miningactivities generate polluted water that is discharged into the Zambezi river basin in the Moatize area without treatment, increasing the risk both to the local environment and to public health because of this water containing significant amounts of metals and metalloids. At the same time, Mozambique is one of the largest producers of cassava peels, most of which are wasted. The aim of the present investigation was to study the use of discarded cassava peels to treat the polluted mine water from Moatize by means of adsorption. The effects both of the pH and of the contact time between the adsorbent, the adsorbate and the adsorption isotherms were examined.For calcium, magnesium, cobalt, mercury and manganese, an equilibrium wasattained in less than 50 min, the removal efficiency of calcium, magnesium, and mercury being greater under alkaline conditions and being greatest for cobalt at pH 4 and for manganese at pH 7.5. The correlation coefficients of the experimental data were very high for the calcium, magnesium and manganese metals as compared with the Langmuir and Freundlich isotherms. For the Langmuir isotherms, it was found that the adsorption of calcium, magnesium, cobalt, mercury, and manganese by the cassava peels was favorable for adsorption generally, whereas for the Freundlich isotherms it was only manganese that was found to be not favorable for adsorption
Water services with independent providers in peri-urban Maputo: Challenges and opportunities for long-term development
Water service delivery to most residents of peri-urban areas of greater Maputo depends largely on alternative service providers. mostly in the form of small-scale independent providers (SSIPs). This paper discusses the present and long-term challenges facing SSIPs in supplying quality water of sufficient quantity in peri-Urban Maputo and possible human health risks associated with the consumption of water provided by SSIPs. Extensive water sampling and analyses were conducted to evaluate the physicochemical and bacteriological quality of water provided by independent providers and the associated human health risks. Borehole pumping tests, the results of which were interpreted using the graphical method of Jacob, were used to evaluate the regional aquifer potential, the long-term impacts of its exploitation and the aquifer Vulnerability to external contamination. From the results of bore hole pumping tests it was concluded that the present yields are in average 33% lower than estimated safe yields and that larger than present yields therefore can be exploited. The aquifer Vulnerability to external contamination (e.g. by E. coli and nitrates) is low, mainly because of low hydraulic loads and the existence of a rather thick (10 to 30 m) sandy unsaturated stratum where bacteria die-off and biological denitrification probably Occurs. However, the aquifer vulnerability to sea sea-water intrusion is high. Currently, the health risks posed to Consumers relying on services provided by SSIPs are small; even so, 13 out of 35 controlled boreholes had either total coliform or faecal coli form levels higher than the WHO standard. In the long run SSIPs may face more serious water quality problems due either to over-exploitation of the aquifer system or increased hydraulic loads resulting from increased Population density
Water reclamation for industrial use in sub-Saharan Africa-A critical review
The increasing world population and growth of industrial development lead to growing water scarcity that, combined with deficient sanitation services, represents serious challenges, particularly in regions like sub-Saharan Africa. Water reclamation is a promising approach to reduce water scarcity, serving as a driving force for better sanitation services and protecting the environment by treating sewage and redistributing for the benefit of other water-dependent applications (e.g., industries). This paper aims to give an overview of the global trends on water reclamation, with a focus on industrial use, and to derive lessons for implementation of water reclamation projects in sub-Saharan Africa. Findings show that extensive experience exists in technology and management practices that can allow successful implementation of water reclamation projects in the region. Under the conditions of deficient sanitation services and low levels of technical expertise, the main challenge is to develop a framework that can facilitate the integration of social and technological methodologies and help in introducing water reclamation in water allocation planning, including the development of specific legislation for industrial water use and disposal.Sanitary Engineerin
Mitigation Potential of Sanitation Infrastructure on Groundwater Contamination by Nitrate in Maputo
In Maputo, the capital of Mozambique, nitrate concentrations above 250 mg L−1 in groundwater have been reported. This happens due to the widespread use of latrines and septic tanks that allow for constant infiltration of its content into the soil and eventually to groundwater sources, a situation that is widespread in the Global South and represents a serious threat for human health and for the environment. This is a reflection of limited access to safe and adequate sanitation services, which the local authorities have set to improve in the forthcoming decades with a recently commissioned city-wide sanitation masterplan serving as a basis for the works. In this article, we aimed at understanding whether the infrastructure projected in the masterplan would lead to a reduction of nitrogen reaching groundwater. Currently, according to our calculations, almost 500 tonnes of nitrogen reach the city’s groundwater sources each year, with the masterplan potentially resulting in a 14% reduction, a small reduction due to its reliance on maintaining and expanding fecal sludge services, without considering investments to improve domestic systems (e.g., construction of contained systems). An alternative, not presented in the Masterplan and put forward by the authors, could be the construction of simplified sewers in two of the city’s most densely populated neighborhoods, with a potential 29% reduction in nitrogen reaching groundwater