Sustainable Technologies and an Implementation Strategy for Arsenic and Fluoride Removal in Developing Areas

The inaccessibility of safe drinking water is a global challenge. The World Health Organization (WHO) estimates that approximately 1.1 billion people, nearly a sixth of the world's population, are currently living without access to an improved drinking water source. A lack of potable water causes a domino effect by contributing to disease, poor sanitation, loss of schooling and over 9.9 billion dollars (US) in lost annual productivity around the world (WHO, 2005). In an effort to combat this problem, the United Nations (UN) designated in of one of its Millennium Development Goals to “reduce by half the proportion of people without sustainable access to safe drinking water and basic sanitation,” (UN, 2005). “One tenth of the global disease burden could be prevented by improving water supply, sanitation, hygiene and management of water resources,” (WHO, 2008). These water issues are further complicated as approximately 1.3 billion people live on less than 1 dollar (US) per day, thus making it difficult for entire communities to develop and pay for access to safe water (WHO, 2005).Along with pathogens, arsenic and fluoride, found naturally in the groundwater of many developing areas, are significant contributors to the global water problem. A 2008 World Health Organization report cited arsenic and fluoride as issues needing further investigation (WHO, 2008). The WHO recommended level for arsenic is 0.01 ppm (WHO, 2004). There are many negative health consequences that result from human consumption of water that exceeds the recommended level of arsenic including liver and skin cancer, skin lesions, circulatory disorders and hyper pigmentation (Berg et al., 2007; Joshi and Chaudhuri, 1996; Katsoyiannis and Zouboulis, 2002; Lenoble et al., 2002). Additionally, a recent health study suggests elevated arsenic consumption by children can reduce intelligence (Wang et al., 2007). Arsenic is found naturally in the atmosphere and can be released into ground water through weathering of rocks, volcanic activity and anthropogenic sources (Smedley, 2002). In many areas of the world arsenic occurs naturally at concentrations well above 0.01 ppm and even 0.05 ppm, the standard set by many developing nations (Berg et al., 2006; Dixit and Hering, 2003; Smedley and Kinniburgh, 2002).Fluoride, like arsenic, is often found naturally occurring in groundwater, particularly in areas of geologic instability (Kloos and Haimanot, 1999). The WHO recommended level for fluoride is 1.5 ppm (WHO, 2004). Small quantities of fluoride, up to approximately 1 ppm, can be helpful because it gets adsorbed into teeth and protects them against acid attacks caused by sugars and other foods (Kloos and Haimanot, 1999). However, human consumption above 1.5 ppm can cause dental fluorosis and above 3 ppm begins to cause skeletal fluorosis. Dental fluorosis causes blackening or mottling of the teeth and skeletal fluorosis can cause severe pain and stiffness of the backbone and joints, and, in severe cases, crippling deformities in bones (Mjengera and Mkongo, 2002; Kaseva, 2006). Additionally, skeletal fluorosis is more severe for children consuming fluoride because their bones are still growing and developing.To combat these problems sustainable technologies, which are inexpensive and easily implemented and maintained, must be developed for use in emerging regions of the world. This presentation evaluates the suitability of animal bone char for use as a filtration technology for the removal of arsenic and fluoride to WHO recommended levels in remote areas of developing countries. Bone char is a low-cost treatment solution which has the potential to be sustainable for developing economies by using simple technologies and local resources in the treatment method.Bone char has been utilized for many years to remove fluoride from drinking water (Bhargava and Killedar, 1991). Bone char is created by crushing and heating bones, but the process of creating bone char for water filtration is not simple as both functional and aesthetic issues must be considered. Charring bones removes organic matter from the bone structure (Kaseva, 2006, Mwaniki, 1992). This process of removing organic material can also avoid the addition of undesirable taste and color to the water during the filtration process (Kaseva, 2006). In this work fish bones were charred at four different temperatures to test the effect of charring temperature on fluoride removal capacity. As shown in Figure 1,400° and 500° C are statistically equally effective at fluoride removal followed by 600°C and then 300° C. Due to its lack of negative aesthetic effects and its effectiveness at fluoride removal, fish bone charred at 500° C was chosen as the primary media for further investigative work to determine ideal parameters and removal capacity.