Research Of Drinking Water Fluoride Removal By Ultra-filtration

Fluoride is widely existence in natural water. It is one of essential trace elements. China provides drinking water fluoride content suitable for 0.5-1.Omg/L, when the lack of fluoride to drinking water, the susceptibility to caries disease. However, if long-term consumption of fluoride concentrations greater than lmg/L of water, easy to cause dental fluorosis, fluoride concentration of long-term consumption of 3-6mg/L of water would cause bone fluorosis. Endemic fluorosis disease are long-term because of high fluoride water or eating local food caused by a chronic fluorosis disease, according to statistics, the distribution in our country about 260 million population, is a serious health hazards endemic in the people. Defluorination of drinking water and people's health is closely related to becoming more and more attention.There are a lot of methods to remove fluoride from drinking water, low pressure membrane technology because of its technical reliability, operating simply, is able to meet increasingly stringent water quality standards and becoming to the most promising methods.In this paper, By using the pre-coagulation + the combination method of low pressure membrane, to treat high fluoride water in the laboratory, under certain conditions, ultra-filtration membranes with a combination of coagulation process can achieve a satisfactory effect of fluoride removal. Pretreatment on the comparison and selection, the effect of chloride coagulation is superior to iron salts, and the coagulation time at 2 minutes is better. In the pretreatment membrane separation process, a suitable pH can enhance the effect of pretreatment reduce membrane fouling, enhance flux through the test, best pH value of coagulation+UF technology is between 6.1-7.1.Appropriate pre-membrane ultra-filtration membrane technology and can greatly improve the drinking water with fluoride ion removal effect. In addition, the experimental proof of coagulation does not increase the membrane fouling, it will flux coagulant dosage increased, in the experiment through backwashing, and flux can be fully recovery.For energy consumption, water production rate, the effect of fluoride removal, membrane price, running costs and membrane fouling, etc. We considered that low-pressure membrane processes, especially coagulation-ultra-filtration process, no doubt that it will be the best drinking water fluoride removal technology. With prices declining of the membrane, ultra-filtration membrane technology in drinking water fluoride removal application will be better prospects.