| Popis: |
Fluoride while beneficial for human health at low concentration shows harmful impacts on skeletal fragility, kidney, nerve damage, etc., if consumed in excess. Several techniques were applied for the removal of excess fluoride from water such as adsorption, membrane separation, ion exchange, precipitation, etc. The selection of a particular technique depends on its specific advantages and disadvantages. These techniques were initially developed at a lab scale and further evolved as pilot plants. Successful pilot plant studies were subsequently developed into community-based applications for fluoride removal. Some of these processes not only removed fluoride but also other unwanted species, namely, phosphate, arsenic, bicarbonates. These plants are extremely popular in various Asian and African countries as they are useful for providing safe drinking water to underprivileged people. In such studies, adsorption was one of the popular methods that employed various adsorbents and the overall cost was about 20 USD/m3. Similarly, precipitation methods like Nalgonda technique were also successfully applied at the cost around 15 USD/m3. Electrocoagulation using aluminium electrode is also a popular method having an operational cost of about 1 USD/m3, whereas equipment cost is substantially high. On the other hand, membrane separation has the highest installation cost of about 800k USD and operational cost of about 0.2 USD/m3. This chapter is specifically discussing about the economics, cost analysis of water defluoridation, and possible applicability. |
