风化花岗岩洗砂尾泥制备4A沸石高效氨氮吸附剂  

4A Zeolite Derived from Weathered Washing Sand Tail Mud as A High-efficiency NH_(4)^(+)-N Adsorbent

作　　者：刘玉慧 陈天虎[1] 王灿[1] 刘海波[1] 陈冬[1] 邹雪华[1] 谢晶晶[1] LIU Yuhui;CHEN Tianhu;WANG Can;LIU Haibo;CHEN Dong;ZOU Xuehua;XIE Jingjing(Laboratory of Nanomineralogy and Environmental Materials,School of Resources and Environmental Engineering,Hefei University of Technology,Hefei 230009,China)

机构地区：[1]纳米矿物与污染控制安徽省普通高校重点实验室,合肥工业大学资源与环境工程学院,合肥230009

出　　处：《硅酸盐学报》2021年第7期1429-1438,共10页Journal of The Chinese Ceramic Society

基　　金：国家自然科学基金(41572028,41872040)。

摘　　要：以风化花岗岩洗砂尾泥为硅铝源,通过水热法制备4A沸石用于处理氨氮污染。通过不同煅烧温度的表征确定尾泥活化最佳温度为600℃,并在单因素实验基础上,以阳离子交换容量(CEC)为响应值,根据中心组合设计–响应面优化法实验设计原理对水钠比、钠硅比、晶化温度、晶化时间等参数进行优化,发现晶化时间对阳离子交换容量影响最大,确定最优工艺参数为:n(H_(2)O):n(NaO_(2))=1.42;n(NaO_(2)):n(SiO_(2))=61.0;晶化温度为90.89℃;晶化时间为8.16 h,此时阳离子交换容量最大为198.5 mmol/100 g。用扫描电子显微镜、X射线衍射对合成4A沸石进行表征,最优工艺参数下所得4A沸石纯度较高。静态吸附实验,pH=4,固液比为0.5 g/L,氨氮浓度为70 mg/L,结果表明:以风化花岗岩洗砂尾泥合成的4A沸石对氨氮吸附量为69.1 mg/g,对氨氮去除机理主要为离子交换,符合二级反应动力学,是一种潜在的氨氮高效吸附材料。4A zeolite was prepared by using calcination and hydrothermal method with weathered granite sand tail mud as silicon and aluminum sources.The optimal calcination temperature was determined to be 600℃.Based on the single-factor experiment,in terms of cation exchange capacity,according to the experimental design principle of central composite,NaO_(2)/SiO_(2),H2O/Na O_(2),crystallization temperature and crystallization time were all optimized.The optimum parameters were determined to be Na_(2)O/Si O_(2)=1.42,H2O/Na_(2)O=61.00,crystallization temperature of 90.89℃,and crystallization time of 8.16 h.The corresponding optimum was 198.50 mmol/100 g.The as-obtained 4A zeolite was characterized by using scanning electron microscopy and X-ray diffraction,indicating that it was highly crystallized.The removal mechanism of NH_(4)^(+)-N from the solutions with the 4A zeolite was attributed to the ion exchange and NH_(4)^(+)-N adsorption on the 4A zeolite,which could be well described with the pseudo-second-order kinetic model and the Langmuir model.In addition,the maximum adsorption capacity to NH_(4)^(+)-N was calculated to be 102.04 mg/g.Therefore,this 4A zeolite could be used as highly efficient adsorbents to remove NH_(4)^(+)-N from water.

关 键 词：4A沸石 环境矿物 水处理 吸附机理 洗砂尾泥 

分 类 号：X75[环境科学与工程—环境工程]