Ecomaterial Technology for Fluoride-polluted Ground water in China

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Since the cause of endemic fluorosis in most areas of China is due to the high fluoride content in drinking water, the principal means of prevention is to decrease the concentration of fluoride in drinking water. To remove fluoride from ground water in China, it is necessary to clear up the following problems ; energy saving, resources saving, and environmental protection.In this research project, we assessed systems of fluoride removal from ground water from the viewpoint of "Ecotechnology". The ecotechnology, namely, ecological technology and/or environmentally conscious technology, has been noticed on recent developments in the science and technology of environmental issues. The ecotechnology includes energy saving, resources saving and environmental protection.(1) Activated alumina was used to removal fluoride from drinking water. The method can treat fluoride without increment of any chemical components in treated drinking water. However, these system result in the problem of recovering of the reagent and treatment of wastewater derived from recovering operation. Then, we proposed an ecotechnological fluoride treatment system, which is composed to combine the adsorption and co-precipitation with aluminum hydroxide, and fluoride was removed aas calcium fluoride from the system.(2) Conversion reaction of calcium phosphates was used to removal from drinking water. Calcium phosphates is converted to fluoroapatite (FAp Ca_5(PO_4)_3F), which is one of natural fluoride resources. Using this reaction, fluoride in drinking water was removed as FAp from the system.