How Are Water Treatment Technologies Used in Developing Countries and Which Are the Most Effective? an Implication to Improve Global Health
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Review Article Page 1 of 14 How are water treatment technologies used in developing countries and which are the most effective? An implication to improve global health Caleb Zinn1, Rachel Bailey1, Noah Barkley1, Mallory Rose Walsh1, Ashlen Hynes1, Tameka Coleman1, Gordana Savic1, Kacie Soltis1, Sharmika Primm1, Ubydul Haque2 1Department of Public Health & Prevention Sciences, Baldwin Wallace University, Berea, OH, USA; 2Department of Biostatistics and Epidemiology, University of North Texas Health Science Center, Fort Worth, TX, USA Contributions: (I) Conception and design: C Zinn, U Haque; (II) Administrative support: None; (III) Provision of study materials or patients: None; (IV) Collection and assembly of data: All authors; (V) Data analysis and interpretation: U Haque; (VI) Manuscript writing: All authors; (VII) Final approval of manuscript: All authors. Correspondence to: Ubydul Haque. Department of Biostatistics and Epidemiology, University of North Texas Health Science Center, Fort Worth, TX, USA. Email: [email protected]. Abstract: Worldwide, there are an estimated 2.3 billion people living in water-scarce and stressed areas. The water in these areas may contain harmful pathogens, such as bacteria, that can have a negative effect on human health. Poor sanitation, lack of hygiene, contaminated water sources, and the overall poor quality of drinking water leads to disease and death amongst people of all ages in underdeveloped and developing countries. In order to better the health of these communities and the quality of water, affordable water treatment technologies that can reduce harmful contamination to potable water standards must continue to be developed. The purpose of this study is to review the currently available techniques, such as solar water disinfection (SODIS), chlorination, ceramic and biosand water filtration and slow sand filtration, that can be utilized in developing countries. A number of peer-reviewed journal articles were reviewed to identify the strengths and weaknesses of each of water treatment technologies. This process is based on the quality/efficiency of the treatment process, the availability/accessibility of the treatment as well as its overall effectiveness. Based on our study, SODIS had the most positive impacts however, membrane filtration shows a potential to become the preferred water treatment method in the future. Affordable and effective water treatment is a vital step towards reducing morbidity, as well as reducing health complications for the present and the future in developing countries. Keywords: Water; treatment; technologies Received: 08 June 2018; Accepted: 21 June 2018; Published: 26 September 2018. doi: 10.21037/jphe.2018.06.02 View this article at: http://dx.doi.org/10.21037/jphe.2018.06.02 Background making it available globally, therefore reducing the risk of health complications and morbidity all across the Water contamination has been a serious public health concern all over the world even in developed countries. globe. In developing countries, the most common form According to the World Health Organization (WHO), of contamination comes from water that has been stored improvements in drinking water, sanitation, hygiene, in poor conditions (3), urging the need for better water and water resource management may reduce the global treatment technologies. It is imperative to treat water disease burden by 10% (1). One of the Millennium for bacteria and other chemical/microbial components Developed Goals is to decentralize drinking water (2), that may compromise public health safety. Advanced and © Journal of Public Health and Emergency. All rights reserved. jphe.amegroups.com J Public Health Emerg 2018;2:25 Page 2 of 14 Journal of Public Health and Emergency, 2018 affordable water treatment technologies are continue to ability to be used easily in homes. These technologies thus be developed to provide assistance to those who cannot make it easier for people to keep sanitary water in their own afford clean water. Prevention strategies such as treating home (8). Studies also showed that the ceramic filters are 3–6 water, educating guidelines for the safe storage of drinking times more cost-effective than the centralized water system water, and practicing improved sanitation techniques, can in place for reduction of waterborne diseases (e.g., diarrheal significantly reduce the risk of deadly waterborne diseases. illness) among children under five (9). The filters are known One common prevention strategy for treating water is to be environmentally friendly in terms of low energy use, chlorination. Chlorination method requires people to add water use, and particulate matter emissions (9,10). one full bottle cap of sodium hypochlorite solution to clear Slow sand filtration (SSF) is another simple method that water, or two bottle caps for turbid water, in a standard can remove pathogens and particles in drinking water (11). sized container, mixed thoroughly by agitating, and When sand surface area increases, it leads to an increase in waiting approximately 30 minutes before consumption (4). possible adsorption spaces on sand and biofilm attached to This method effectively inactivates most bacteria and the sand grains. It was reported that an increase of 0.25 to viruses that cause diarrheal disease however it is not as 0.63 mm in d 10 of filter sand ended up decreasing the total effective at removing protozoa, such as Cryptosporidium (4). coliform bacteria removal from 98.6% to 96%, which shows Chlorination is inexpensive, generally easy to use and the high efficiency (11). maintain, however there is a lower disinfection effectiveness Membrane filters are typically manufactured as flat in turbid waters, and it has potential for long-term health sheet stock or as hollow fibers then formed into membrane effects, such as some types of cancers such as Colorectal modules. Modules typically involve potting or sealing the (4,5). This water treatment method has also been membrane material into an assembly which are designed distributed free of charge in a number of disaster areas for long-term use. Some examples of modules used include, including Indonesia, India and Myanmar. hollow-fiber modules and spiral-wound modules. One of the widely used prevention strategies to treat In this study, we will investigate the strengths and water, Solar Water Disinfection (SODIS), is a safe and weaknesses of various water treatment technologies. Our simple way to kill pathogens in water, making it safe to study will be based on published pee-reviewed journal drink (6). Results have shown that exposing a filled water articles as well as our observations of drinking water bottle to the sun for at least 6 hours reduces the number industry trends. It is noted that our study is specifically of pathogens in the water, and thus greatly reduces health designed for applications in developing countries. We complications (e.g., diarrhea) (7). SODIS uses the sun’s will also provide recommendations to promote drinking ultraviolet radiation to improve the quality of the water. It water treatment technology guidelines and suggestions, is an inexpensive and easy method to improve the quality so that many people in developing countries can access of drinking water in a household. Studies also investigated safe drinking water. We do believe that this work will be low-cost SODIS-based point-of-use (POU) household beneficial to local communities in developing countries, devices in Pakistan (7). The study concluded that SODIS Engineers without Borders (EWB), and other stakeholders were successful in treating contaminated water and can who need substantial understanding of available water be used for people living in large cities facing shortage of treatment technologies for well-informed decision-making. potable water (7). Another well-known prevention strategies are ceramic Methods and biosand water filters (BSF). Biosand filtration is a slow-sand filter adapted for use in the home. The most We searched literature through PubMed, Google Scholars, widely used version of the BSF is a concrete container and Medline (EBSCO) using the key words “water approximately 0.9 meters tall and 0.3 meters square filled treatment technology”, “world”, “disease”,” drinking with sand. The water level is maintained at 5–6 centimeters water”, “public health and drinking water”, “public health above sand layer to grow on top of sand which in turn drinking water and disease”. Initially we retrieved 56 papers helps reduce disease-causing organisms. A plate with holes however, after reviewing them, only 38 were considered for is placed on top of the sand to prevent disruption of the this study (Box 1). bioactive layer when water is added to the system. The These articles were selected based off of multiple factors filters can be effective POUs due to their versatility and including a discussion regarding various water treatment © Journal of Public Health and Emergency. All rights reserved. jphe.amegroups.com J Public Health Emerg 2018;2:25 Journal of Public Health and Emergency, 2018 Page 3 of 14 Box 1 Literature search for water treatment in developing countries cannot be addressed since multiple studies only focused Period searched: from 2000 to September 2017 on the effectiveness in the removal of contaminants, while Source: PubMed, Google Scholars, Medline (EBSCO) others focused on usage by those in developing countries. All of the studies focused on the removal of a particular Search terms: “Water Treatment Technology” AND