More than a Drop in the Bucket: Decentralized Membrane-Based Drinking Water Refill Stations in Southeast Asia

Abstract

Decentralized membrane-based water treatment and refill stations represent a viable and growing business model in Southeast Asia, which rely upon the purchase of water from refill stations by consumers. This feature article discusses these water treatment and refill stations, including the appropriateness of the technology, the suitability of the business models employed, and the long-term environmental and operational sustainability of these systems. We also provide an outlook for the sector, highlighting key technical challenges that need to be addressed in order to improve the capacity of these systems, such that they can become an effective and financially viable solution.

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“…The first projects in developing nations installed them as small-scale systems supplying purified drinking water to entire villages or small communities. Modern stations can run on solar power and contain storage tanks for periods of unfavourable sunlight conditions (Sima and Elimelech, 2013;Elasaad et al, 2015). However, the treated water must still be transported and stored in households after treatment, which leads to a risk of recontamination (Gundry et al, 2006).…”

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“…Boreholes are sometimes available for domestic water supply systems; however, the quality of these and all other water sources (rain, river, source) is not typically monitored [11,48]. Alternative decentralized technologies for the developing world should be small-scale, energy efficient, environmentally sound, and use locally available resources [7]. They should also be capable of being controlled and maintained by the local community.…”

“…In recent years the use of decentralized water treatment systems has increased worldwide, but particularly in the developing world [1][2][3][4][5][6][7][8][9][10]. Due to their relatively small spatial scale and low carbon footprint, decentralized water filtration systems have a low environmental impact on water resources because they do not discharge effluent into waterways [4].…”

“…Membrane filtration technologies typically exhibit a number of advantageous attributes including [3,7]: (i) the ability to produce very high quality water (low aqueous contaminant concentrations); (ii) simple modular design and the ability to be automated; (iii) no requirement for chemicals; and (iv) the ability to effectively remove bacteria, viruses and other microorganisms. Conventional membrane filtration can be divided into three stages: pre-filtration (media filtration), ultra-filtration and reverse osmosis.…”

“…However, three key disadvantages associated with membrane filtration systems are the high installation cost, high energy requirement, and the necessity for maintenance (removal of membrane fouling material). As a consequence, over the past few decades much research has been conducted into the development of more cost effective and simple water treatment systems for the developing world [3,4,7,[12][13][14][15][16][17][18]. These efforts include the development of renewable energy powered membrane (RE-membrane) technologies [19,20].…”