World Water Day: Valuing water for sustainable development of South Africa

Creating contextually relevant research to tackle issues of sustainability of water resources, wastewater treatment and purification of drinking water in South Africa

As part of the celebration of World Water Day which was commemorated yesterday, 22 March, and South Africa’s National Water Week, which ended yesterday, we are highlighting the work of the DSI-NRF SARChI Chair in Water Quality and Waste Management Research, led by Professor Maggy NB Momba from the Tshwane University of Technology (TUT).

World Water Day focuses on the importance of freshwater and raises awareness of the 2.2 billion people living without access to safe water. The UN’s theme for 2021, Valuing Water, explores the enormous and complex value of water to our households, food, culture, health, education, economics and the integrity of our natural environment.

The greatest challenge of sustainable development includes the quality and quantity of water resources. This is among the objectives of improving health and living conditions and ensuring equitable as well as a sustainable use of natural resources and a better life for all.

South Africa is considered a water-stressed country with an average annual rainfall of 495mm compared with the world’s average of 1 033mm. More pressure is exerted on the natural water resources with increasing industrialisation and urbanisation patterns. The situation is further exacerbated by the alarming pollution of the available water sources and the destruction of river catchments.  Moreover, the presence of waterborne microorganisms in water bodies causes a heavy burden of diseases in South Africa, especially in rural areas, since waterborne outbreaks such as cholera, typhoid fever and diarrhoeal diseases occur every year.

This scenario will continue to present communities with increasing incidence of water-related diseases and their complications if no adequate understanding of the origin, survival and effect of microorganisms associated with water sources and the protection of water resources are not taken into consideration.

Consequently, an integrated management approach of water and wastewater should be adopted in South Africa to avoid the ripple effect on the environmental, social and economic growth.

For the last eight years, the DST-NRF SARChI Chair for Water Quality and Wastewater Management has addressed the major challenges of sustaining the quality of water sources and the provision of safe drinking water, especially in non-metropolitan areas of developing countries in general and South Africa in particular.

Developing cost effective water treatment systems

For this purpose, four cost-effective decentralised drinking water treatment systems have been designed, constructed/improved and evaluated for their efficiency to remove pollutants, especially turbidity and microbial pollutants. These include:

• Bio-sand zeolite silver-impregnated clay granular filters (BSZ -SICG filter);
• Silver-impregnated porous pots (SIPP);
• Prototype-based nano-silver alginate/sand filter systems; and
• Prototype-based nano-silver resin/sand filter systems for the disinfection of drinking water.

Among these household water treatment systems (HWTS), BSZ -SICG and SIPP filters were deployed in the Makwane Village of the Limpopo Province.  The implementation of these HWTSs in every household of the Makwane Village produced drinking water free of Escherichia coli, Shigella spp., Salmonella spp. and Vibrio cholerae, Cryptosporidium parvum and Giardia lamblia.

As a result, there was a reduction in the incidence of diarrhoea by 96.2%. With the improved flow rates, both HWTSs achieved the required volume of 25 litres per person per day. What makes this solution even more viable is that all materials used in the manufacturing process of the selected devices are locally available. The full journal article on this experiment is available here.

A Provisional Patent Specification (No 2016/02883) has been obtained for the BSZ -SICG filter. The two other prototype-based water treatment systems have demonstrated their capability to produce safe drinking water by removing pathogenic bacteria and protozoan parasites. They are also considered alternative cost-effective technologies for the disinfection of groundwater and surface water in rural communities.

Understanding microorganisms associated with water sources

Furthermore, in understanding the origin, survival and effect of microorganisms associated with water sources, the SARChI Chair has been able to develop strategies allowing for the rapid diagnosis of waterborne infections and their control through the establishment of a state-of-the-art molecular diagnostic laboratory and a number of research activities. These include:

• Determining the impact of seasonal variations on the extent to which sediments were polluted with microbial pathogens and characterising the remobilisation dynamics of these pathogens in water resource sediments in selected areas and ultimately to predict pathogen loads under different climatic conditions. A rapid method that allows the maximum recovery of microorganisms within riverbed sediments, specifically Escherichia coli, was developed;
• Establishing the genetic relatedness between indicator bacteria (faecal coliform and faecal enterococci) and pathogenic bacteria (Salmonella spp. and Shigella spp.) of both surface water and riverbed sediments;
• Ascertaining the prevalence and genetic characteristics of Giardia and Cryptosporidium genotypes from river water and riverbed sediments and understanding the genotypic distribution data between these environments;
• Investigating the health threat posed to HIV/AIDS patients by container household water quality in rural areas of Ugu District Municipality, KwaZulu Natal Province.

Tracking antibiotic-resistant bacteria of environmental isolates

The lack of strategies to contain and track antibiotic-resistant bacteria (ARB) and genes (ARGs) of environmental isolates from clinics and healthcare settings motivated the conceptualisation and design of a research project focusing on a “Multidimensional approach to characterisation and tracking of ARB in terrestrial and aquatic environments of South African rural and urban areas”.  This has resulted in the development of a computer-iImplemented genome tracking method and system which has also obtained a Provisional Patent Specification (No 2020/04797). This developed Web tool will assist scientists and policymakers in formulating appropriate strategies to combat the transmission of pathogenic ARBs. Additionally, geospatial mapping of ARB genomes will allow for the identification of national and international hotspots of antibiotic resistance and actions for epidemiological containment. The GenoTrack Web tool may also provide baseline information necessary to link the environmental spread of antimicrobial resistance (AMR) to routes of transmission across different environments. 

Management of wastewater

The SARChI Chair has enabled the management of wastewater for the protection of water resources by developing a prototype-based solar radiation-ozonation coupled system for the treatment of wastewater using metal-doped titanium dioxide. Furthermore, indigenous wastewater and mine water microbiomes have been discovered, and these have the potential to assist in the remediation of petroleum-contaminated water and polluted mine water resources.

In conclusion, the Chair has not only made significant scientific contributions in fields of health-related water microbiology; antibiotic resistance bacteria and antibiotic resistant genes; water and wastewater treatment; and bioremediation/biotechnology, but has also contributed to skills development in South Africa’s water sector by capacitating and training Master’s and Doctoral students from South Africa and other African countries. Research activities are internationally excellent in terms of originality, significance and rigour and substantially advance knowledge and understanding in these fields.