Research On The Adsorption Property Of The Rice Husk Activated Carbon As Defluorination Agent

Fluoride is widely distributed in nature and it is one of the necessary elements to maintain the body's physical activity. A small amount of fluorine is helpful to teeth health and bone growth and can improve the tooth enamel's resistance to the acid corrosion of bacteria, and effectively prevent saprodontia. Fluoride is good for bone health, especially the prevention of osteoporosis. But an excess of fluoride can also affect human health,leading to diseases such as dental fluorosis. China is one of the countries in the world which are suffered seriously by regional fluorosis,as there are still tens of millions of people drink fluoride water. In response to this grim phenomenon, various countries in the world have stepped up research on the fluorine-containing wastewater treatment, the treatment includes: precipitation method, ion exchange method, adsorption method,method of reverse osmosis and so on. For its simple to operate, low cost, and stable effect,adsorption is the widely used treatment of fluorine-containing wastewater.In this paper, "use waste to treat pollution" is the basic idea, and through the dry activation of Na OH we get activated carbon based on rice husk, it has good surface properties, and it is cheap and easy to get. And through loading Mg O, Pullulan modified polysaccharides, we prepared Mg OPC complex adsorbent. And we use a fixed bed reactor as a carrier, and investigate dynamic adsorption properties of Mg OPC adsorbent.This experiment mathematically fixed bed reactor fitted breakthrough curves(BTC)by Thomas and Yan model, investigate the influence on the defluorinating performance of different operating parameters and environmental conditions and find the optimum conditions for the defluorination of the fixed bed reactor. The experiment shows that adsorption is influenced by a variety of factors,such as when the quality of the adsorption bed is high and the flow rate is low, the defluoridation effect is better; adsorbent has strong ability to adapt to the initial concentration, ambient temperature and p H; among the interfering ions, except HCO3-,in absorbing F-,Cl-? SO42-? NO3-are competing, and mutually reinforcing.The article also discusses the regeneration of Mg OPC, results showed that: hot regeneration is the best way of sorbent regeneration, the effect of other single way forregeneration of the adsorbent regeneration is not obvious, pickling- thermal regeneration and caustic- thermal regeneration can also achieve good results.In short, Mg OPC sorbent reduces the cost of raw materials, and it has good adsorption properties, good ability to adapt to the environment and anti-jamming capability of coexisting ions.It has no secondary pollution, so it is an ideal defluorination agent and has a good practical application prospect.