Twenty-five years of wastewater reclamation in windhoek, Namibia

Haarhoff, Johannes; Merwe, Ben van der

doi:10.2166/wst.1996.0658

Cited by 46 publications

(32 citation statements)

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“…One possible mechanism is the recycling of wastewaters and drainage water that can be used in the place of other fresh water sources for irrigation. Types of wastewaters used for recycling include treated and untreated sewage effluent (Asano et al 1996, Haarhoff & Van der Merwe 1996, Shereif et al 1995, storm water runoff (Asano et al 1996, Dillon et al 1994, domestic greywater (Anderson 1996), and industrial wastewater (Asano et al 1996, Guillaume & Xanthoulis 1996. For the purposes of this paper all of these water types are considered effluents which have the capacity to be reused.…”

Section: Introductionmentioning

confidence: 99%

Reuse of effluent water—benefits and risks

Toze

2006

Agricultural Water Management

567

285

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There is an increasing trend to require more efficient use of water resources, both in urban and rural environments. A major mechanism that can be used to achieve greater efficiencies is the reuse of water that once would have been discarded into the environment after use. The reuse of water for agricultural irrigation is often viewed as a positive means of recycling water due to the potential large volumes of water that can be used. Recycled water can have the advantage of being a constant, reliable water source and reduces the amount of water extracted from the environment. In addition, in some cases treatment requirements may be need to be less than for water used in an urban environment due to less potential human contact. There are concerns and unknowns, however, about the impact of the quality of the recycled water, both on the crop itself and on the end users of the crops. Water quality issues that can create real or perceived problems in agriculture include nutrient and sodium concentrations, heavy metals, and the presence of contaminants such as human and animal pathogens, pharmaceuticals and endocrine disruptors. Social attitudes to the use of crops that have been irrigated with recycled waters and the resulting impact on market value of crops are also a major consideration. This paper will discuss the benefits from using different types of recycled water and outline the current knowledge and opinions relating to risks such as water quality issues. KeywordsWastewater, recycling, soil, contaminants, pathogens, irrigation IntroductionIncreasing efficiencies in crop management and the continuing increases in crop yields has increased demands on water resources for irrigation purposes. Effluents are reused for irrigation purposes in many countries around the world on all of the populated continents (USEPA 1992). A number of these countries have developed guidelines that give quality criteria and advice on how effluents should reused for irrigation purposes. Examples of these guidelines are summarised in the USEPA guidelines for water reuse manual (USEPA 1992).

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Section: Introductionmentioning

confidence: 99%

Reuse of effluent water—benefits and risks

Toze

2006

Agricultural Water Management

567

285

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“…A reclamation plant that was used to treat water from one of the dams was upgraded to treat water from the city's Gammams wastewater treatment plant [60]. After successful tests, treated wastewater was blended with dam water and added directly to the city's potable water supply [60].…”

Section: Windhoek Namibiamentioning

confidence: 99%

“…After successful tests, treated wastewater was blended with dam water and added directly to the city's potable water supply [60].…”

Section: Windhoek Namibiamentioning

confidence: 99%

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The Role of Emotions in Drinking Recycled Water

Leong

2016

Water

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Abstract:As global freshwater supplies shrink, recycled drinking water (RDW) has become an increasingly important source of water supply. However, RDW remains an underinvested resource despite being a safe and reliable source of water. The dominant hypothesis is that RDW has been rejected on emotional grounds of disgust, a visceral psychological reaction known as the "yuck" factor. This paper investigates the role of emotions in technical decision-making and applies it to RDW implementation. It tests two specific hypotheses. First, that negative emotions affect the policy process through a negative "goal definition" of the problem, making it unattractive to stakeholders. Second, the emotional quality of policies can be manipulated by policy entrepreneurs. These hypotheses are tested on two cases of RDW-one failed and the other successful. It finds that narratives in the former are relatively low in emotional intensity, with themes such as sustainability and governance, whereas the second case displays narratives charged with anger, social injustice, and disgust. This emphasizes the role of narratives, especially when visceral reactions such as disgust and anger interact with larger social and political discourses. Finally, we offer policy implications on how understanding the role of emotions can help in the implementation of RDW.

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“…In the city of Windhoek (Namibia), the conversion of wastewater to drinking water has been in place for 40 years (Haarhoff and Van der Merwe, 1996). Currently, the reclamation plant has a capacity of 7.5 Mm 3 year −1 and its water constitutes about 25% of the city's potable water supply, in which CAS is followed by a multiple barrier series of reclamation processes: pre-ozonation, coagulation/flocculation, dissolved air flotation, dual media filtration, main ozonation, activated carbon filtration, ultrafiltration and chlorination (Lahnsteiner and Lempert, 2007).…”

Section: Potable Water Recovery From Sewage: Feasibility Provenmentioning

confidence: 99%

ZeroWasteWater: short-cycling of wastewater resources for sustainable cities of the future

Verstraete

Vlaeminck

2011

International Journal of Sustainable Development & World Ec

201

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Actual sewage treatment relies on conventional activated sludge (CAS), which reaches sufficiently low carbon, nitrogen and phosphorus effluent levels, but is not cost-effective, hardly achieves recovery, requires electricity equivalent to a fossil fuel consumption of 85 kWh per inhabitant equivalent (IE) per year and has an operational CO 2 footprint of 80 kg CO 2 IE −1 year −1 . Projected water and phosphorus shortages and the need to lower greenhouse gas emissions force us to rethink wastewater treatment for sustainable cities of the future. ZeroWasteWater offers an approach to short-cycle water, energy and valuable materials while adequately abating pathogens, heavy metals and trace organics. A less diluted waste stream will be obtained from sewerage improvements, a more rational use of potable water and the addition of ground kitchen waste, complemented by an advanced physicochemical or/and biological concentration step at the entry of the sewage treatment plant. Anaerobic digestion will recover electricity from the concentrated stream and further treatment will render a value of 6.2 EUR IE −1 year −1 under the form of the nutrients nitrogen and phosphorus, and the carbon-sequestrating biochar. In the water stream, residual nitrogen will be removed through partial nitritation and anammox, followed by heat recovery and add-on membrane technologies yielding potable water (> 65 m 3 IE −1 year −1 ). Overall, compared to a CAS system without sludge digestion, the recovery of energy and nutrient in ZeroWasteWater avoids a fossil fuel use of 439 kWh IE −1 year −1 and an operational emission of 88 kg CO 2 IE −1 year −1. Interestingly, such approach is expected to be economically viable. The key challenges remain to incorporate water chain management in holistic urban planning and to render a cradle to cradle approach which society will find acceptable.

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Twenty-five years of wastewater reclamation in windhoek, Namibia

Cited by 46 publications

References 1 publication

Reuse of effluent water—benefits and risks

Reuse of effluent water—benefits and risks

The Role of Emotions in Drinking Recycled Water

ZeroWasteWater: short-cycling of wastewater resources for sustainable cities of the future

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