改性硅藻土的制备、表征及其在富营养化水体除磷中的应用

利用吉林原土和FeCl3作为主要原料,制备应用于抑制湖泊富营养化的除磷材料—改性硅藻土,并利用物理吸附仪、扫描电镜、射线粉末衍射仪（XRD）等对改性硅藻土进行表征,此外,探讨了吸附时间、pH以及温度等对改性硅藻土除磷性能的影响。结果显示：（1）经改性后,硅藻土中Fe元素的含量有所增加,杂质含量则有所降低;微孔明显增多,孔径增大,表面负载一定量的颗粒物,粗糙度增大,比表面积较原硅藻土增大6倍。（2）在水体除磷应用中,当吸附时间达到20min时,吸附趋向平衡;在酸性条件下改性硅藻土的除磷效果好于碱性条件下的除磷效果;在25℃下改性硅藻土对磷的吸附能力较其他温度下强;（3）Langmuir和Freundlich等温吸附方程都能较好地描述硅藻土对磷的等温吸附特征,用Freundlich吸附等温方程来描述改性硅藻土对水中磷的吸附更为准确。

The preparation,characterization and application of the modified diatomite

The modified diatomite was obtained by using Jilin raw diatomite and FeCl3 as the main raw materials and was used in inhibiting the eutrophication of eutrophied water.The structure and particle size of the obtained modified diatomite was characterized by physical adsorption instruments,SEM,XRD et al.In addition,we probed to the effects of adsorption time,pH value,temperature et al on the adsorption capability of the modified diatomite.The results showed：（1） The content of Fe in the modified diatomite increased,whereas the content of impurity decreased,and the micro-pore was uniformly distributed on the surfaces of the modified diatomite.Besides,both the number and the size of the micro-pore had increased obviously.Since there were a certain amount of particles on the surfaces of the modified diatomite,the roughness of surface increased dramatically.As a result,the surface area of the modified diatomite had increased six times.（2） When the adsorption time reached to 20 minutes,the adsorption tend to balance,and it performed better under acidic conditions than that under alkaline conditions.The optimum temperature for the modified diatomite to remove phosphorus from the water body was 25 ℃.（3） Isothermal equations,such as Langmuir and Freundich could describe the characteristic of the isothermal adsorption of modified diatomite well,but the Freundich Isothermal equation described more exactly.