The Development Of A Novel Adsorbent For Fluoride Removal And Its Application Research

Fluoride removal from drinking water has become an urgent task in China,owing to the wide distribution of high concentration fluoride groundwater which could do serious harm to human health.So it is of great significance to develop a novel fluoride adsorbent with high fluoride removal performance and low price.Almost all of the existing adsorbents have the problems of low adsorption capacity and an acidic applicable pH range.A novel Mg-Fe-Ce complex metal oxide with high fluoride adsorption performance was successfully developed in the present study,the Mg-Fe-Ce complex metal oxide powder was granulated via extrusion with binder(GMFC),and its fluoride removal performance and analysis of the surface properties before and after fluoride adsorption by using modern characterization techniques were evaluated.A kind of household fluoride removal device and the appropriate scale fluorine removal equipment were development for field application.The following results were obtained through the research:1.Based on the high affinity of the rare earth material to fluorine and the synergy of complex metal oxide,A novel Mg-Fe-Ce complex metal oxide with high fluoride adsorption performance was successfully developed.The optimum pH range for fluoride adsorption was 4~5.5,and the maximum adsorption capacity calculated from the two-site Langmuir isotherm equation at pH 7.0 was as high as 204 mg/g,indicating that the new adsorbent was very competitive in comparison with other adsorbents.The normal coexisting anions in drinking water,such as sulfate,nitrate and chlorine,did not affect fluoride adsorption performance,which was conducive to its practical applications in high fluoride groundwater.2.The Mg-Fe-Ce complex metal oxide powder was granulated via extrusion with binder(GMFC).The results showed that the optimal ratio of Binder and adsorbent powder was 0.6 to 0.7,and the optimum GMFC was 1.6 mm cylinder granule diameter with high compress strength and adsorption capacity.Small column adsorption experimental results indicated that the GMFC has high adsorption capacity and suitability.XRD characterization shows that the addition of binder has little impact on amorphous structure and surface hydroxyl.3.Based on the developed GMFC,the domestic fluorine removal device and the appropriate scale fluorine removal equipment were designed.The domestic fluorine removal device was applicated in yanqing county of Beijing.For fluoride bearing groundwater fluoride concentration(1.1-1.4)mg/L,pH 7.8,treatment of water for 4500bv),the Water fluoride concentration was still less than 0.3 mg/L,and the GMFC exhibited the accumulated fluoride adsorption capacity of 6.8 mg/g,it is enough to maintain a family of three for nearly three years of drinking and cooking water,showing an attractive application perspective.The appropriate scale in the construction of a water plant in Anhui Jieshou City(20 m~3/h)fluoride demonstration project,the water quality is in accordance with the relevant requirements.