Water SA

http://www.scielo.org.za/scielo.php?script=sci_issues&pid=1816-7950&lng=pt&nrm=iso

List of Papers (Total 223)

Understanding farmers

Wastewater has emerged as an alternative source of water. Since the agricultural sector remains the largest water user world-wide, it is the main potential user of treated wastewater. However, while there are trade-offs in using wastewater, it may be the only option in water-scarce regions. South Africa has included water reuse as a policy option; hence the aim of this study is...

Understanding farmers

Wastewater has emerged as an alternative source of water. Since the agricultural sector remains the largest water user world-wide, it is the main potential user of treated wastewater. However, while there are trade-offs in using wastewater, it may be the only option in water-scarce regions. South Africa has included water reuse as a policy option; hence the aim of this study is...

Potable water use of residential consumers in the Cape Town metropolitan area with access to groundwater as a supplementary household water source

The potable water use recorded by 3 579 residential consumer water meters in Cape Town, South Africa, was analysed as part of this research. The focus was on selected residential properties in serviced areas, with additional private access to groundwater as a supplementary household water source. Private consumers in South Africa are not normally required to report on, or meter...

Model simulations of rainfall over southern Africa and its eastern escarpment

Rainfall simulations over southern and tropical Africa in the form of low-resolution Atmospheric Model Intercomparison Project (AMIP) simulations and higher resolution National Centre for Environmental Prediction (NCEP) reanalysis downscalings are presented and evaluated in this paper. The model used is the conformal-cubic atmospheric model (CCAM), a variable-resolution global...

The major and trace element chemistry of fish and lake water within major South African catchments

Chemical elements in lake water are incorporated into fish tissues through bioconcentration and biomagnification. Lake water and fish tissue samples from 23 lakes, located within 4 major South African catchments, were analysed to investigate the link between element concentrations in lake water and otolith, fin spine, muscle, liver and gill tissues. The comparison is complicated...

Understanding farmers

Wastewater has emerged as an alternative source of water. Since the agricultural sector remains the largest water user world-wide, it is the main potential user of treated wastewater. However, while there are trade-offs in using wastewater, it may be the only option in water-scarce regions. South Africa has included water reuse as a policy option; hence the aim of this study is...

Paradigms and theories in water governance: The case of South Africa's National Water Resource Strategy, Second Edition

This paper indicates the influence of paradigms and theories on the development of South Africa's National Water Resource Strategy, Second Edition. Five paradigms exist: positivism, postpositivism, interpretivism/constructivism, critical theories and the participatory paradigm. I use the PULSE3 framework for analysis that I developed to analyse the NWRS2. I found that positivism...

Sublethal effects of temperature on freshwater organisms, with special reference to aquatic insects

Water temperature is a key variable affecting aquatic organisms. Understanding their response to elevated water temperatures is important for estimating upper thermal limits, and ultimately for assisting with setting defendable, biologically-relevant water temperature guidelines for lotic systems. Sublethal effects impacting on an individual organism or species may manifest at...

Conductivity as an indicator of surface water quality in the proximity of ferrochrome smelters in South Africa

South Africa is one of the leading ferrochrome (FeCr) producing countries. One of the main environmental and health-related issues associated with FeCr production is the possible generation of Cr(VI). However, Cr(VI) is not the only potential pollutant that has to be considered during FeCr production. Various water-soluble species are present in FeCr waste materials and in...

In-line rheological characterisation of wastewater sludges using non-invasive ultrasound sensor technology

The performance of a new ultrasound transducer, which can measure velocity profiles non-invasively through high-grade stainless steel pipes, was evaluated for the first time with secondary wastewater sludges. This work is a follow-up study on the feasibility work initially done by the same authors. In-line process control based on accurate rheological characterisation for treated...

A reduction in mining and industrial effluents in the Blesbokspruit Ramsar wetland, South Africa: Has the quality of the surface water in the wetland improved?

The Blesbokspruit Wetland, 40 km southeast of Johannesburg, South Africa, was listed as a Ramsar Wetland of International Importance in 1986. Following discharges of mine-waters in the mid-1990s, the wetland no longer complied with the Ramsar criteria. This paper reports on historical trends in surface water quality of the Blesbokspruit, as a step towards restoration to Ramsar...

Framework for optimizing chlorine dose in small - to medium-sized water distribution systems: A case of a residential neighbourhood in Lahore, Pakistan

To maintain desirable residual chlorine for a groundwater source, optimizing the chlorine dose in small- to medium-sized water distribution systems (SM-WDS) is a daunting task in developing countries. Mostly, operators add a random chlorine dose without recognizing the smaller size of their distribution network. In this research, a modelling framework for optimizing chlorine dose...

A conceptual theoretical framework to integrally assess the possible impacts of climate change on domestic irrigation water use

Southern Africa is likely to experience higher evapotranspiration and altered rainfall characteristics due to global warming and climate change. Climate-driven water use may potentially stress water supply facilities due to increased demand and reduced surface water yield. This paper presents a conceptual theoretical framework for assessing impacts of climate change on domestic...

Application of hydropedological insights in hydrological modelling of the Stevenson-Hamilton Research Supersite, Kruger National Park, South Africa

Soil information is increasingly sought after for hydrological modelling, as the importance of soil in the hydrological cycle is understood better. In this paper the output of a digital soil mapping exercise was used as the soil input into a distributed hydrological model (ACRU) for a test site within the Stevenson-Hamilton Research Supersite, Kruger National Park (South Africa...

A demand-based management option to address boat congestion at the Sundays River Estuary, Eastern Cape, South Africa

The Sundays River Estuary situated in the Eastern Cape is an example of a South African Estuary experiencing congestion externalities, mainly vis-à-vis motorised boat use. This paper employs a choice model to estimate people's preferences for less boat congestion on the Sundays River Estuary. The results show that visitors to the estuary are willing to trade off a levy of ZAR 35...

A scoping study on the prevalence of Escherichia coli and Enterococcus species in harvested rainwater stored in tanks

Rainwater harvesting (RWH) is a relatively inexpensive technology that has the potential to provide safe water in communities where conventional technologies are difficult to implement. In this study, the microbiological quality of rainwater harvested from rooftops and ground-surface runoff was evaluated based on the concentrations of Escherichia coli, total coliforms and...

Removal of nutrient and heavy metal loads from sewage effluent using vetiver grass, Chrysopogon zizanioides (L.) Roberty

Urban cities in many developing nations face the challenge of relieving the pressure exerted on overloaded sewage treatment works. Apart from limited financial capacity, complementary treatment methods like phyto-extraction of pollutants from the effluent have not been fully exploited, particularly in southern Africa. A study was conducted in Harare, Zimbabwe, to assess the...

Evaluation of an automated struvite reactor to recover phosphorus from source-separated urine collected at urine diversion toilets in eThekwini

In the present study we attempted to develop a reactor system to recover phosphorus by struvite precipitation, and which can be installed anywhere in the field without access to a laboratory. A reactor was developed that can run fully automated and recover up to 93% of total phosphorus (total P). Turbidity and conductivity signals were investigated as automation proxies for...

Influence of selected biotopes on chironomid-based bioassessment of the Swartkops River, Eastern Cape, South Africa

Impact of pollution on aquatic biota is usually assessed by comparing the assemblage at an impacted site with those at a control or reference site. In South Africa, except in rivers where not all biotopes are represented, the characterisation of a macroinvertebrate-based pollution effect is usually based on samples collected from three distinct biotopes, i.e., stones, vegetation...

Conceptual framework for sewer pump problems allowing for fuzzy logic application

Sewer pump station problems in separate sewer systems (separate from stormwater drainage systems) were investigated in order to derive a conceptual framework for decision making. Notwithstanding the fundamental service that efficient sewage pumping provides to a community, it was apparent that limited research has been published on the topic. Research was undertaken to identify...

Water footprint assessment to inform water management and policy making in South Africa

One method to inform decisions with respect to sustainable, efficient and equitable water allocation and use is water footprint assessment (WFA). This paper presents a preliminary WFA of South Africa (SA) based on data for the period 1996-2005. Crop production was found to contribute about 75% of the total water footprint of national production. The total water footprint of crop...

Effects of salinity on the survival of the Brackwater mussel, Brachidontes virgiliae, in the St Lucia estuarine system, South Africa

During drought periods, the razor clam Solen cylindraceus is the dominant bivalve in the St Lucia estuarine system, although restricted to its South Lake region. However, with the recent onset of a wet phase, the mussel Brachidontes virgiliae has become widespread and overwhelmingly dominant throughout the system. The salinity tolerance of B. virgiliae is here determined using...

Optimum reliable operation of water distribution networks by minimising energy cost and chlorine dosage

In recent decades much attention has been paid to optimal operation of water distribution networks (WDNs). In this regard, the system operation costs, including energy and disinfection chemicals, as well as system reliability should be simultaneously considered in system performance optimisation, to provide the minimum required level of performance in failure condition and to...

The potential anti-androgenic effect of agricultural pesticides used in the Western Cape: In vitro investigation of mixture effects

Although it is known that environmental chemicals can affect the oestrogenic system, far less attention has been paid to chemicals interacting with the androgen receptor (AR). Pesticides, particularly fungicides, have been shown to competitively bind or affect expression of the AR in an inhibiting manner. Few studies have addressed anti-androgenic effects of agrochemical use in...

SST prediction methodologies and verification considerations for dynamical mid-summer rainfall forecasts for South Africa

ABSTRACT Seasonal-to-interannual hindcasts (re-forecasts) for December-January-February (DJF) produced at a 1-month lead-time by the ECHAM4.5 atmospheric general circulation model (AGCM) are verified after calibrating model output to DJF rainfall at 94 districts across South Africa. The AGCM is forced with SST forecasts produced by (i) statistically predicted SSTs, and (ii...