Water Journal : Water Journal August 2015
water AUGUST 2015 44 Feature article membranes: Toray (flat sheet), Norit (tubular) and Pall Corporation (hollow fibre). The Pall pilot plant was never successfully commissioned, so only the Toray and Norit pilot plants produced results. The MBRs were evaluated daily for 12 months in terms of: permeate quality; fouling potential of the permeate; fouling rate (cleaning frequency); stable fluxes; and peak fluxes. The most important criterion was the composition of permeate. The permeate quality was evaluated in terms of the permeate water quality being able to consistently meet set water quality objectives and standards, including the removal of Contaminants of Emerging Concern (CECs, such as endocrine disruptors, pharmaceuticals and personal care products), for the production of potable water. Although there were minor differences in product water quality between the processes, most were compliant with the SANS241- 1:2011 drinking water standard7 . A parallel bench scale comparison of five different process trains, utilising different combinations of membrane bioreactors (MBRs), reverse osmosis (RO), ultraviolet light (UV), ozone (O3), nanofiltration (NF), and granular activated carbon (GAC) yielded results demonstrating that streamlined process trains such as MBR-RO-UV (replicating the Singapore process) or MBR- NF-UV are as effective as treatment trains with additional processes such as ozonation and GAC (MBRO3/GAC-NF -UV). Cost estimates suggested that the membrane-based process MBR-RO-UV would require less capital investment than process MBR-O3/GAC-NF -UV, the ozone/GAC-based treatment process. challenges and Future research South Africa’s current research questions are about what to monitor (microbiological, chemical, organic micropollutants, endocrine disrupting compounds and CECs), and how to undertake the process of public engagement. Monitoring, management and communication of water quality and public acceptance in the direct reclamation of municipal wastewater for drinking purposes Water reclamation plants are operating in Emalahleni (IPR), Beaufort West (DPR), George (IPR) and Mossel Bay (industrial), while DPR in Durban and Hermanus is at an advanced planning stage. The main concerns regarding DPR focus on potential health risks. The aim of this project is to develop a framework for IPR and DPR, consisting of health risk-based monitoring (for compliance and operational barriers, including engineered buffers), funding sources and regulatory approval. The main impacts of implementation of the framework will be improved sustainability of supplementary and alternative drinking water supply to alleviate water scarcity, to improve health and to stimulate economic development. An investigation into the social, institutional and economic implications of re-using reclaimed wastewater for domestic application in South Africa Despite people’s acknowledgement of water scarcity, the general public often has little knowledge of water treatment and wastewater management. The research literature is almost silent on community awareness and engagement on the issue of DPR. The need to engage communities is a principle enshrined within the South African constitution and is reiterated in the water service regulation strategy, which emphasises the need for citizens’ voice. The underestimation of this need cannot be more vividly illustrated than by the recent service delivery protests in South Africa, stemming from experiences and/or perceptions of unsatisfactory service delivery, with drinking water being no exception. This project will provide an understanding of the social, economic and institutional implications and consequences of DPR. Emerging contaminants in wastewater treated for direct potable re-use: the human health risk priorities in South Africa The possible presence of CECs in reclaimed municipal wastewater is of critical concern because of potential adverse health impacts. Criteria in the evaluation of DPR include: (1) primary health concerns of wastewater re-use that are the long-term health outcomes of ingesting chemical contaminants found in recycled water; (2) health risks of using recycled water as a potable water supply compared against similar risk by conventional water supplies; and (3) the need for toxicity assessments. This project will identify CECs in South African reclaimed potable water, their sources, pathways and receptors, potential risk from exposure to these chemicals, performance of water reclamation treatment systems and risks for DPR. Assessment of DPR systems for the removal of contaminants that may have negative health impacts will provide a good basis for the development of South African guidelines for implementation of barriers, monitoring programs and assessment programs to eliminate or minimise risks, and can improve public acceptance of reclaimed water. conclusIon The real value of water is apparent only when there is a risk of running out. This is illustrated by projects such as the re-use initiative of Durban Water Recycling8 and Queensland’s Western Corridor Project. The most compelling drivers for IPR and DPR have been shortages of water in the locations where demand for potable water exceeds supply; the uniqueness of water’s diseconomies of scale, in as much as the more volume of water is required, the further one has to go to get it; the corollary economic comparison of re-use of wastewater versus discharge to the receiving environment; and the increasing demand nationally as the human population both increases and becomes more urbanised. Communicating with and engaging the broader community in a discussion of the role of potable re-use in our water future is still, however, a significant challenge. WJ acknoWledgements The Author gratefully acknowledges the technical and cost data, and other information provided by the WRC, WRRF and AWRCE and their project teams. Some of this information was used in a global perspectives review article entitled “Global Research Agency Perspectives on Potable Water Reuse”, published in Environmental Science: Water Research & Technology. The co-authors, Julie Minton, Melissa Meeker and Mark O’Donohue and publishers, The Royal Society of Chemistry, are gratefully acknowledged. the author Dr Jo Burgess (email: firstname.lastname@example.org) is Research Manager, KSA 3: Water Use and Wastewater Management at the Water Research Commission in Pretoria, South Africa. 5 G Metcalf, L Pillay, LC Murutu, S Chiburi, N Gumede and P Gaydon (2014): Wastewater Reclamation for Potable Reuse Volume 1: Evaluation of Membrane Bioreactor Technology for Pre-Treatment, Research Report no. 1894/1/14, Water Research Commission, Pretoria, South Africa. Available online at www.wrc.org. za/Pages/DisplayItem.aspx?ItemID=11079&FromURL=%2fPages%2fKH_AdvancedSearch.aspx%3fdt%3d1%26ms%3d%26d%3dWastewater+reclamation+for+p otable+reuse+Volume+1%3a+Evaluation+of+membrane+bioreactor+technology+for+pre-treatment%26start%3d1. 6 G Metcalf, L Pillay, LC Murutu, S Chiburi, N Gumede and P Gaydon (2014): Wastewater Reclamation for Potable Reuse Volume 2: Integration of MBR Technology With Advanced Treatment Processes, Research Report No. TT611/14 Water Research Commission, Pretoria, South Africa. Available online at www.wrc.org.za/ Pages/DisplayItem.aspx?ItemID=11147&FromURL=%2fPages%2fKH_AdvancedSearch.aspx%3fdt%3d%26ms%3d%26d%3dWastewater+reclamation+for+potabl e+reuse+volume+2%3a+Integration+of+MBR+technology+with+advanced+treatment+processes%26start%3d1. 7 SANS 241-1:2011 Drinking Water Part 1: Microbiological, Physical, Aesthetic and Chemical Determinants, South African Bureau of Standards, Pretoria, South Africa, 2011. 8 Water & Sanitation Africa, Nov/Dec 2011. South Africa’s Award-Winning Seawater Desalination Plant 29-33; Celebrating a Decade of Achievement 4-5 . www.awa.asn.au The AusTrAliAn WATer DirecTory 2015 26th Edition An invaluable resource and reference tool for the Australian water industry To view the digital version now visit www.awa.asn.au/WaterDirectory www.awa.asn.au/WaterDirectory www.awa.asn.au/WaterDirectory www.awa.asn.au/WaterDirectory For your convenience, the 2015 Australian Water Directory is now available online...
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