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Development of Synthetic Hydroxyapatite-Based Household Defluoridation Unit
Journal
Advances in Water Purification Techniques: Meeting the Needs of Developed and Developing Countries
Date Issued
2019-01-01
Author(s)
Khare, Ayushi
Singh, Sanjay
Chaudhari, Sanjeev
Abstract
Groundwater contamination with elevated levels of fluoride is a major environmental issue worldwide. In this study an attempt has been made to develop a domestic defluoridation unit by using synthetic hydroxyapatite (HAP), synthesized at room temperature by precipitation method. Laboratory experiments with simulated fluoride containing water (5 and 10mg/L F−) revealed fluoride concentration in treated water could be brought down to less than 1mg/L by HAP. It was observed that during treatment with HAP, phosphate concentration in treated water increased, which is not desirable. As few studies indicate that the presence of phosphate reduces the bioavailability of calcium by excreting precipitated calcium from the body, which can cause calcium deficiency in the body. Thus experiments were conducted with amended aqueous calcium (50mg/L) and it has been found to reduce residual phosphate concentration to below detectable limits in treated water. A household unit was fabricated using HAP particles, coarse aggregates, and fine aggregates. Sixteen units were installed in households of three villages (Sitapat, Dilawara, Karondia Bhan) of district Dhar in Madhya Pradesh state of India. Bi-weekly monitoring of household defluoridation unit for 3 months indicated reduction in fluoride concentration from ~2.5 to below 0.5mg/L and residual phosphate concentration to be below detectable limits. User’s health survey after 65days of regular consumption of treated water, indicated improvements in health conditions, thus it seems that the developed household unit holds promise for fluoride removal in rural areas.
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