Situation of fluoride contamination in well waters in Sri Lanka, and removal of fluoride by chicken bone char

在斯里兰卡的干旱地区，如中北部省和东南部省，井水中的氟浓度高到足以引起氟斑牙和氟骨症。本研究对全国1300口沃茨进行了氟含量测定。为了去除井水中的氟，在600 ℃下热解1小时制备了鸡骨炭（CBC）。斯里兰卡丹布勒市的一个家庭使用装有CBC的除氟过滤器，以确认过滤器的性能。结果表明，含有560 g CBC的过滤器可处理1400 L井水，相当于4人家庭140天的平均用水量。根据一级反应动力学模型，建立了能较好地再现处理后水中氟浓度的动力学模型。

In the dry zone of Sri Lanka, such as north central province and southeast province, fluoride concentration in the well water is high enough to cause dental fluorosis and bone fluorosis. In this research, we measured 1300 well waters to determine the fluoride concentration of the well water in the whole counry. According to the analytical result, a spatial distribution map for fluoride was created.To remove fluoride from well water, chicken bone char(CBC) was produced by pyrolysis at 600 C for 1 hour. Fluoride removal filter packed with CBC was operated by a family in Dambulla city of Sri Lanka to confirm the performance of the filter. It was revealed that 1400 L of the well water, which is equivalent to the averaged consumption of water for 140 days in a family with 4 person, could be treated by the filter containing 560 g of CBC. A kinetics model, which reproduced the fluoride concentration of treated water quite well, was established based on the first-order reaction.