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High fluoride concentrations in groundwater pose a health risk to people living in the Rift valley of Ethiopia and beyond. The Nalgonda and electrolytic defluoridation (EDF) fluoride treatment systems were developed and adapted in India for fluoride removal. A recent study evaluated twenty Nalgonda techniques that were implemented in the Rift valley of Ethiopia. A number of these systems were found to be non-functional or had never been utilized. The purpose of this study is to evaluate the performance of the Nalgonda technique and seek ways to enhance the fluoride uptake capacities. Further, pilot testing of the EDF system was conducted in the Rift Valley of Ethiopia to evaluate its effectiveness at fluoride removal using natural groundwater in this setting. This study has shown that the performance of the Nalgonda system was significantly enhanced by adding aluminum hydro(oxide) (AO) and cow bone char powder into the existing Nalgonda systems; the initial fluoride concentration of 9.3 mg/L was lowered to 2.5 mg/L on average. In addition to the increased effectiveness at fluoride removal, the addition of AO and cow bone char powder produced significantly less sludge compared to the existing Nalgonda system. The EDF system proved to be effective at removing the excess fluoride concentration in drinking water in the Rift Valley of Ethiopia; the initial fluoride concentration of 7.9 mg/L was lowered to 2.8 mg/L meeting the USEPA standard fluoride level of 4 mg/L. The pilot study showed Aluminum leaching into the treated water. Thus, further optimization of the electrode size, electrolysis time, and voltage/current used during the electrolysis process is needed to meet the WHO target treatment goal of 1.5 mg/L fluoride level and eliminate aluminum leaching as well. Key words: Electrolytic defluoridation, fluoride, Nalgonda, pilot-testing, sustainability.

This paper addresses how business models inform viability of different fluoride treatment technologies for developing countries as well as the pursuit of financial and operational sustainability. Excess fluoride concentrations in drinking water supplies negatively impact the health of communities living in fluoride affected regions of the world by causing dental and skeletal fluorosis and other severe socio-economic problems. Given that fluoride mitigation solutions have proven elusive, we apply business model logic to compare fluoride removal technologies to examine the financial sustainability of water service provisions. We analyze the investment cost of producing fluoride safe water, the annual revenues generated, and the net benefits obtained from different technologies. Furthermore, the reduced medical costs and productivity losses averted due to access to fluoride safe water can lead to an average annual cost saving of $67 per person. Our results validate the use of business models to help evaluate different technologies as a means of pursuing sustainable applications for safe drinking water.

Thermally activated cow bone is widely utilized for treating fluoride impacted drinking water to meet the World Health Organization guideline value of 1.5 mg/L. However, the fluoride removal capacity of bone char is low, leaving room for further improvement. This study, therefore, strives to improve the fluoride adsorption capacity of cow bone by using chemical activation in place of thermal activation. Chemically activated cow bones (CABs) had, on average, a four-fold higher fluoride adsorption capacity than bone char. Characterization of the most effective CAB were made to explore potential reasons for the increased fluoride adsorption capacity. The X-ray diffraction pattern of the CAB showed formation of bassanite and monetite minerals which may be responsible for the higher fluoride adsorption capacity. Chemical activation is also a lower-cost production process than the thermal activation of cow bone. Further, a higher mass of media was recovered per unit mass of starting material during chemical activation. Therefore, this research shows that increased fluoride removal capacity can be achieved with chemical activation of cow bone while reducing activation costs and greatly increasing product yield per unit mass of starting material, all of which support further evaluation and field testing of this material.

Various fluoride adsorbents have been studied for removal of excess fluoride from drinking water to meet the World Health Organization (WHO) Guideline value of 1.5 mg/L. Production of these adsorbents emits contaminants that can affect human health and the environment, but the extent of these impacts is currently unknown. This study evaluates the environmental impacts of four low-cost and easy to use adsorbents: activated alumina, aluminum oxide amended wood char, bone char, and treated alum waste. The environmental impacts of these adsorbents were evaluated using life cycle assessment (LCA). The life cycle stages considered were raw material acquisition, adsorbent manufacturing, and waste management. The functional unit was defined as the quantity of adsorbent necessary to reduce the fluoride concentration of 100,000 L of water from 10 mg/L to the World Health Organization recommended drinking water level of 1.5 mg/L. Eco-indicator and the Tool for Reduction and Assessment of Chemicals and other Environmental Impacts (TRACI) were used to interpret the environmental impacts. The results indicate that the environmental impacts of these adsorbents vary greatly using a common functional unit of treating 100,000 L (100 m3) of fluoride-impacted water. A key determining factor for the impacts is the fluoride adsorption capacity of the adsorbent material because this affects how much material is required to produce safe water. Aluminum oxide amended wood char had the highest overall negative environmental impact in all impact categories, and the lowest adsorption capacity. The two adsorbents that performed the best (lowest environmental impact) were the bone char and the treated alum waste. The environmental impacts of the adsorbents can be reduced by increasing their fluoride adsorption capacity and/or carefully selecting key process components, such as the distance and means of transportation, particularly for activated alumina. Regeneration and reuse of spent adsorbents has the potential to minimize impacts to ecosystem quality.

In an effort to further understand the fourfold higher fluoride removal capacity of chemically activated cow bone (CAB) previously reported compared to bone char, fundamental properties of ...

In this study, a novel material, chemically activated cow bone (CAB), was further evaluated for fluoride removal via laboratory batch and field column studies using fluoride-impacted groundwaters in the Rift Valley of Ethiopia. Regeneration of the exhausted CAB was evaluated using 0.05 M NaOH and 0.01 M Ca(OH)2 solutions. Water-quality parameters were analyzed to ensure that the CAB-treated water is safe for human consumption. The study indicated that the CAB produced in the laboratory and field showed fourfold improvement in fluoride removal capacity as compared to thermally activated cow bone (commonly known as bone char). The study also showed that more than 92% adsorption capacity of the exhausted CAB media can be regained using 0.05 M NaOH and 0.01 M Ca(OH)2 solutions. The water-quality analysis conducted on the highly fluoride-impacted drinking waters treated using CAB media were found to be safe for public consumption. Therefore, these results further reinforce that CAB media can be used to...