斜发沸石负载Zn-Al层状双氢氧化物对水体中氟离子的吸附性能研究
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摘要
氟是人体必须的微量元素之一,适量的氟摄入可促进人体牙齿与骨骼发育,但超过一定范围将对人体健康造成严重危害。饮用水是人体摄入氟的主要来源,近期关于北京市海淀区农村饮用水水质调查研究表明,海淀区许多农村地区地下水氟含量明显超标,这严重威胁了当地居民的身体健康。沸石与层状双金属氢氧化物具有优异的吸附性能,本课题的研究目的是利用辽西南地区储量丰富、成本低廉的天然沸石,通过负载双金属氢氧化物来提高其吸附量,开发出高效的除氟材料。
天然沸石经过XRD、化学分析与电子探针分析,表明其主要物相为斜发沸石与石英,含量分别为83.18%与7.26%。负载层状双金属氢氧化物后经过XRD与SEM分析,发现XRD结果中可看出明显的层状双金氢氧化物的峰,SEM图片中可看出沸石表面有白色物质。
动力学吸附实验的优化条件为:pH4～6,用量5g/L,平衡时间8h,振荡速度180r/min。动力学研究表明:吸附反应动力学符合准二级反应模型,其模型计算吸附量q_e(cal)与实验吸附量q_e(exp)相近,其相关系数R~2都大于0.99;内扩散模型计算结果推测吸附反应过程分两个阶段,第一个阶段为材料表面吸附,第二个阶段吸附由材料表面进入内孔,且第一阶段的吸附速率比第二阶段快。吸附等温线的曲线形状为S型,langmuir模型不适合解释本实验的等温线,Freundlich模型表明在氟浓度低时吸附不利,氟浓度高时吸附有利。D-R模型计算结果表明,在氟浓度较低时,吸附主要为物理吸附;在氟浓度较高时,吸附主要为化学吸附。除氟机理分析表明除氟过程为离子交换过程,起主要除氟作用的物质为层状双金属氢氧化物。
与其他沸石负载方法(负载铝与负载锆)相比,负载层状双金属氢氧化物除氟更具优势,吸附量比原矿天然沸石吸附量增大14倍左右,在去除高浓度氟方面具有良好的实际应用前景。
Fluorine is a trace element necessary for human body,appropriate amount of fluoride intake may promote the development of human teeth and bones,but beyond a certain range will cause harm to human health.Drinking water is the main source of fluoride consumption for human.The recently research on the drinking water quality in rural areas of Haidian District shows that the fluoride content of groundwater significantly exceed,which is a serious threat to the health of local residents.Zeolite and layered double hydroxides(LDHs) have excellent adsorptive performance,the purpose of this paper is to develop an efficient fluoride removal materials using low-cost natural zeolite of southwest Liaoning,Zn-A1 layered double hydroxides will be loaded on the surface of zeolite to improve its adsorption capacity.
The X-ray diffraction,chemical analysis and electron microprobe analysis results indicate the main phases of natural zeolite are clinoptilolite and quartz.After loaded Zn-Al layered double hydroxides,the Zn-Al LDHs peaks can be found,and some white substance can be seen at the surface of zeolite through the scanning electron micrograph.
For kinetics study,the experiments demonstrate that maximum fluoride removal was obtained at a pH between 4 and 6,and it took 8h to attain equilibrium,the optimized amount is 5g/L and the speed of oscillation is 180 r/min.Kinetics adsorption profiles offered excellent fit with pseudo-second-order model with a high R~2 value over 0.99.The intraparticle diffusion model indicates there are two-stage adsorption processes,in the first stage,the fluoride adsorption occurs at the surface,in the second stage the adsorption goes into the hole,the adsorption rate of the second stage is faster than the first stage.The shape of adsorption isotherm curve is S, Langrnuir model is not suitable to explain the experimental isotherm,Freundlich model demonstrate that the adsorption is unfavorable in the low fluoride concentration and is favorable in the high concentration.The calculated results of D-R model indicate that when the fluoride concentration is low,the adsorption is mainly physical;when the fluoride concentration is high,the adsorption is mainly chemical. The mechanism of fluoride removal for this material is ion exchange,the double hydroxide play a major role in the removal of fluoride.
Compared with other methods(aluminum and ziconium),zeolite supported layered double hydroxide is better,the amount of adsorption is 14 times than natural zeolite,it has a good prospect for practical application on the removal of high fluoride concentration.
天然沸石经过XRD、化学分析与电子探针分析,表明其主要物相为斜发沸石与石英,含量分别为83.18%与7.26%。负载层状双金属氢氧化物后经过XRD与SEM分析,发现XRD结果中可看出明显的层状双金氢氧化物的峰,SEM图片中可看出沸石表面有白色物质。
动力学吸附实验的优化条件为:pH4～6,用量5g/L,平衡时间8h,振荡速度180r/min。动力学研究表明:吸附反应动力学符合准二级反应模型,其模型计算吸附量q_e(cal)与实验吸附量q_e(exp)相近,其相关系数R~2都大于0.99;内扩散模型计算结果推测吸附反应过程分两个阶段,第一个阶段为材料表面吸附,第二个阶段吸附由材料表面进入内孔,且第一阶段的吸附速率比第二阶段快。吸附等温线的曲线形状为S型,langmuir模型不适合解释本实验的等温线,Freundlich模型表明在氟浓度低时吸附不利,氟浓度高时吸附有利。D-R模型计算结果表明,在氟浓度较低时,吸附主要为物理吸附;在氟浓度较高时,吸附主要为化学吸附。除氟机理分析表明除氟过程为离子交换过程,起主要除氟作用的物质为层状双金属氢氧化物。
与其他沸石负载方法(负载铝与负载锆)相比,负载层状双金属氢氧化物除氟更具优势,吸附量比原矿天然沸石吸附量增大14倍左右,在去除高浓度氟方面具有良好的实际应用前景。
Fluorine is a trace element necessary for human body,appropriate amount of fluoride intake may promote the development of human teeth and bones,but beyond a certain range will cause harm to human health.Drinking water is the main source of fluoride consumption for human.The recently research on the drinking water quality in rural areas of Haidian District shows that the fluoride content of groundwater significantly exceed,which is a serious threat to the health of local residents.Zeolite and layered double hydroxides(LDHs) have excellent adsorptive performance,the purpose of this paper is to develop an efficient fluoride removal materials using low-cost natural zeolite of southwest Liaoning,Zn-A1 layered double hydroxides will be loaded on the surface of zeolite to improve its adsorption capacity.
The X-ray diffraction,chemical analysis and electron microprobe analysis results indicate the main phases of natural zeolite are clinoptilolite and quartz.After loaded Zn-Al layered double hydroxides,the Zn-Al LDHs peaks can be found,and some white substance can be seen at the surface of zeolite through the scanning electron micrograph.
For kinetics study,the experiments demonstrate that maximum fluoride removal was obtained at a pH between 4 and 6,and it took 8h to attain equilibrium,the optimized amount is 5g/L and the speed of oscillation is 180 r/min.Kinetics adsorption profiles offered excellent fit with pseudo-second-order model with a high R~2 value over 0.99.The intraparticle diffusion model indicates there are two-stage adsorption processes,in the first stage,the fluoride adsorption occurs at the surface,in the second stage the adsorption goes into the hole,the adsorption rate of the second stage is faster than the first stage.The shape of adsorption isotherm curve is S, Langrnuir model is not suitable to explain the experimental isotherm,Freundlich model demonstrate that the adsorption is unfavorable in the low fluoride concentration and is favorable in the high concentration.The calculated results of D-R model indicate that when the fluoride concentration is low,the adsorption is mainly physical;when the fluoride concentration is high,the adsorption is mainly chemical. The mechanism of fluoride removal for this material is ion exchange,the double hydroxide play a major role in the removal of fluoride.
Compared with other methods(aluminum and ziconium),zeolite supported layered double hydroxide is better,the amount of adsorption is 14 times than natural zeolite,it has a good prospect for practical application on the removal of high fluoride concentration.
引文
[1]Eva Kumar,Amit Bhamagar,Minkyu Ji,et al,Defluoridation from aqueous solutions by granular ferric hydroxide(GFH)[J],Water Research,2009,43:490-498
[2]冯雅,辉裴柳,氟与人体健康[J],生物学教学,2007,32(3):43-44
[3]马鸿文等,工业矿物与岩石[M],化学工业出版社(北京),2005,59-68
[4]陈国阶,佘大富等,环境中的氟[M],科学出版社(北京),1990,33-34
[5]蔡隆九,氟污染及其控制方法[J],包钢科技,2001,27(1):56-60
[6]唐志坚,苏庆平,李朝华等,氟的环境地球化学及形态分析[J],化学工程师,2008,7:34-37
[7]徐明钻,许永胜,地方性氟中毒研究--以贵州省为例[J],安徽农业科学,2008,36(11):4660-4665
[8]沈振华,张玉先,改性沸石用于饮用水除氟的试验研究[J],江苏环境科技,2006,19(1):5-7
[9]WHO(World Health Organization),Fluoride in Drinking-water,World Health Organization,Printed by TJ International(Ltd).Padstow.Comwall.UK,2006.
[10]WHO(World Health Organization),Guidelines for Drinking Water Quality,World Health Organization,Geneva,1993.
[11]张超杰,周琪,含氟水治理研究进展[J],给水排水,2002,28(12):26-29
[12]姜川,费学宁,冷冻分凝法处理高氟水的方法研究[J],天津城市建设学院学报,2008,14(2):126-129
[13]魏平方,邹斌,李凡修,双极铝电极电凝聚除氟研究[J],油气田环境保护,2000,20(1):20-23
[14]范建伟,张杰,钙盐.电凝聚法处理含氟工业废水[J],工业用水与废水,2006,37(1):48-51
[15]周春琼,邓先和,刘海敏等,吸附法处理含氟水溶液的研究与应用[J],水处理技术,2006,32(1):1-5
[16]赵薇,焦瑞,曹培华,包头天然沸石活化降氟研究[J],内蒙古石油化工,2006,12:7-8
[17]董岁月,李佩成,周孝德,改型沸石除氟过程的热力学和动力学研究[J],西北农林科 技大学学报,2006,34(9):121-124
[18]陈方明,陆琦,方沸石水质净化剂的制备及其除氟研究[J],环境工程学报,2007,1(9):30-34
[19]孙忠,侯晓勇,改型沸石在饮水净化中的应用研究[J],非金属矿,2002,25(2):49-50
[20]詹予忠,李玲玲,俞晓江等,活化斜发沸石吸附除水中氟的研究[J],中国矿业,2006,15(2):68-70
[21]程有普,闻建平,杨素亮,天然沸石活化及除氟性能[J],化学工业与工程,2006,23(3):236-239
[22]苗茵,刘晓飞.李曼尼,铁活化天然斜发沸石吸附水中氟的研究[J],内蒙古大学学报,2005,36(6):647-652
[23]刘雪,骆定法,改型天然沸石净化高氟饮用水研究[J],非金属矿,2004,27(1):47-49
[24]Ali Tor,Nadide Danaoglu,Gulsin Arslan,et al.,Removal of fluoride from water by using granular red mud:Batch and column studies[J],Journal of Hazardous Materials,2009,164:271-278
[25]S.Ayoob,A.K.Gupta,P.B.Bhakat,et al,Investigations on the kinetics and mechanisms of sorptive removal of fluoride from water using alumina cement granules[J],Chemical Engineering Journal,2008,140:6-14
[26]S.Meenakshi,C.Sairam Sundaram,Rugmini Sukumar,Enhanced fluoride sorpfion by mechanochemically activated kaolinites[J],Journal of Hazardous Materials,2008,153:164-172
[27]Ali Tor,Removal of fluoride from an aqueous solution by using montmorillonite[J],Desalination,2006,201:267-276
[28]A.M.Raichur,M.Jyoti Basu,Adsorption of fluoride onto mixed rare earth oxides[J],Separation and Purification Technology,2001,24:121-127
[29]彭真万等,矿物学基础[M],地质出版社(北京),2008:193-194
[30)薛玉,李广贺,沸石结构对氨氮吸附性能的影响[J],环境污染与防治,2003,25(4):209-210
[31]胡宏杰,金梅,沸石的结构和性能及应用展望[J],矿产保护与利用,1996,6:25-28
[32]潘兆橹等,应用矿物学[M],武汉工业大学出版社(武汉),1993,281-284
[33]刘媛,层状双金属氢氧化物的合成与应用[J],化工时刊,2005,19(12):59-62
[34]杜宝中,王宏军,郑刚等,纳米层状双金属氢氧化物的制备及结构表征[J],无机盐工 业,2007,39(5):26-28
[35]金志琳,侯万国,张春光,Mg-Al-NO_3层状双金属氢氧化物电性质研究[J],化学学报,2002,61(8):1208-1212
[36]S.Mandal,S.Mayadevi,Adsorption of fluoride ions by Zn-Al layered double hydroxides[J],Applied Clay Science,2008,40:54-62
[37]S.Mandal,S.Mayadevi,Cellulose supported layered double hydroxides for the adsorption of fluoride from aqueous solution[J],Chemosphere,2008,72:995-998
[38]倪哲明,胥倩,潘国祥等,层状双金属氢氧化物微观结构与性质的理论研究进展[J],物理化学学报,2009,25(4):792-805
[39]韩小伟,王英,水滑石及类水滑石材料的合成及应用新进展[J],江苏化工,2003,31(2):26-31
[40]Federica Prinetto,Giovanna Ghiotti,Patrick Graffin,et al.Synthesis and characterization of sol-gel Mg/A1 and Ni/Al layered double hydroxides and comparison with co-precipitated samples[J],Microporous and Mesoporous Materials,2000,39:229-247
[41]朱茂旭,李艳苹,张良等,水滑石及其焙烧产物对磷酸根的吸附[J],矿物学报,2005,25(1):27-32
[42]刘淼,杨俊佼,武国庆等,镁铝双金属氢氧化物及氧化物去除硫离子(s~(2-))性能及其机理研究[J],无机化学学报,2006,22(10):1771-1777
[43]陈银飞,葛忠华,吕德伟,MgAlFe复合氧化物氧化吸附SO_2的性质[J],环境科学学报,2001,21(3):307-311
[44]刘钰,杨向光,王学中,以水滑石类化合物为前体的Co-M-Al(M=过渡金属)复合氧化物对催化消除NO_x活性的研究[J],化学学报,1999,57:782-789
[45]许家友,佘晓峰,李光照等,水滑石填充PVC形态结构的研究[J],塑料工业,2005,33(6):45-47
[46]郑红,戚洪彬,梁树干,大学化学实验[M],地质出版社(北京),2005:60-63
[47]印永嘉,奚正楷,李大珍,物理化学简明教程[M],高等教育出版社(北京),1992:436-454
[48]叶振华,化工吸附分离过程[M],中国石化出版社(北京),1992:57-58
[2]冯雅,辉裴柳,氟与人体健康[J],生物学教学,2007,32(3):43-44
[3]马鸿文等,工业矿物与岩石[M],化学工业出版社(北京),2005,59-68
[4]陈国阶,佘大富等,环境中的氟[M],科学出版社(北京),1990,33-34
[5]蔡隆九,氟污染及其控制方法[J],包钢科技,2001,27(1):56-60
[6]唐志坚,苏庆平,李朝华等,氟的环境地球化学及形态分析[J],化学工程师,2008,7:34-37
[7]徐明钻,许永胜,地方性氟中毒研究--以贵州省为例[J],安徽农业科学,2008,36(11):4660-4665
[8]沈振华,张玉先,改性沸石用于饮用水除氟的试验研究[J],江苏环境科技,2006,19(1):5-7
[9]WHO(World Health Organization),Fluoride in Drinking-water,World Health Organization,Printed by TJ International(Ltd).Padstow.Comwall.UK,2006.
[10]WHO(World Health Organization),Guidelines for Drinking Water Quality,World Health Organization,Geneva,1993.
[11]张超杰,周琪,含氟水治理研究进展[J],给水排水,2002,28(12):26-29
[12]姜川,费学宁,冷冻分凝法处理高氟水的方法研究[J],天津城市建设学院学报,2008,14(2):126-129
[13]魏平方,邹斌,李凡修,双极铝电极电凝聚除氟研究[J],油气田环境保护,2000,20(1):20-23
[14]范建伟,张杰,钙盐.电凝聚法处理含氟工业废水[J],工业用水与废水,2006,37(1):48-51
[15]周春琼,邓先和,刘海敏等,吸附法处理含氟水溶液的研究与应用[J],水处理技术,2006,32(1):1-5
[16]赵薇,焦瑞,曹培华,包头天然沸石活化降氟研究[J],内蒙古石油化工,2006,12:7-8
[17]董岁月,李佩成,周孝德,改型沸石除氟过程的热力学和动力学研究[J],西北农林科 技大学学报,2006,34(9):121-124
[18]陈方明,陆琦,方沸石水质净化剂的制备及其除氟研究[J],环境工程学报,2007,1(9):30-34
[19]孙忠,侯晓勇,改型沸石在饮水净化中的应用研究[J],非金属矿,2002,25(2):49-50
[20]詹予忠,李玲玲,俞晓江等,活化斜发沸石吸附除水中氟的研究[J],中国矿业,2006,15(2):68-70
[21]程有普,闻建平,杨素亮,天然沸石活化及除氟性能[J],化学工业与工程,2006,23(3):236-239
[22]苗茵,刘晓飞.李曼尼,铁活化天然斜发沸石吸附水中氟的研究[J],内蒙古大学学报,2005,36(6):647-652
[23]刘雪,骆定法,改型天然沸石净化高氟饮用水研究[J],非金属矿,2004,27(1):47-49
[24]Ali Tor,Nadide Danaoglu,Gulsin Arslan,et al.,Removal of fluoride from water by using granular red mud:Batch and column studies[J],Journal of Hazardous Materials,2009,164:271-278
[25]S.Ayoob,A.K.Gupta,P.B.Bhakat,et al,Investigations on the kinetics and mechanisms of sorptive removal of fluoride from water using alumina cement granules[J],Chemical Engineering Journal,2008,140:6-14
[26]S.Meenakshi,C.Sairam Sundaram,Rugmini Sukumar,Enhanced fluoride sorpfion by mechanochemically activated kaolinites[J],Journal of Hazardous Materials,2008,153:164-172
[27]Ali Tor,Removal of fluoride from an aqueous solution by using montmorillonite[J],Desalination,2006,201:267-276
[28]A.M.Raichur,M.Jyoti Basu,Adsorption of fluoride onto mixed rare earth oxides[J],Separation and Purification Technology,2001,24:121-127
[29]彭真万等,矿物学基础[M],地质出版社(北京),2008:193-194
[30)薛玉,李广贺,沸石结构对氨氮吸附性能的影响[J],环境污染与防治,2003,25(4):209-210
[31]胡宏杰,金梅,沸石的结构和性能及应用展望[J],矿产保护与利用,1996,6:25-28
[32]潘兆橹等,应用矿物学[M],武汉工业大学出版社(武汉),1993,281-284
[33]刘媛,层状双金属氢氧化物的合成与应用[J],化工时刊,2005,19(12):59-62
[34]杜宝中,王宏军,郑刚等,纳米层状双金属氢氧化物的制备及结构表征[J],无机盐工 业,2007,39(5):26-28
[35]金志琳,侯万国,张春光,Mg-Al-NO_3层状双金属氢氧化物电性质研究[J],化学学报,2002,61(8):1208-1212
[36]S.Mandal,S.Mayadevi,Adsorption of fluoride ions by Zn-Al layered double hydroxides[J],Applied Clay Science,2008,40:54-62
[37]S.Mandal,S.Mayadevi,Cellulose supported layered double hydroxides for the adsorption of fluoride from aqueous solution[J],Chemosphere,2008,72:995-998
[38]倪哲明,胥倩,潘国祥等,层状双金属氢氧化物微观结构与性质的理论研究进展[J],物理化学学报,2009,25(4):792-805
[39]韩小伟,王英,水滑石及类水滑石材料的合成及应用新进展[J],江苏化工,2003,31(2):26-31
[40]Federica Prinetto,Giovanna Ghiotti,Patrick Graffin,et al.Synthesis and characterization of sol-gel Mg/A1 and Ni/Al layered double hydroxides and comparison with co-precipitated samples[J],Microporous and Mesoporous Materials,2000,39:229-247
[41]朱茂旭,李艳苹,张良等,水滑石及其焙烧产物对磷酸根的吸附[J],矿物学报,2005,25(1):27-32
[42]刘淼,杨俊佼,武国庆等,镁铝双金属氢氧化物及氧化物去除硫离子(s~(2-))性能及其机理研究[J],无机化学学报,2006,22(10):1771-1777
[43]陈银飞,葛忠华,吕德伟,MgAlFe复合氧化物氧化吸附SO_2的性质[J],环境科学学报,2001,21(3):307-311
[44]刘钰,杨向光,王学中,以水滑石类化合物为前体的Co-M-Al(M=过渡金属)复合氧化物对催化消除NO_x活性的研究[J],化学学报,1999,57:782-789
[45]许家友,佘晓峰,李光照等,水滑石填充PVC形态结构的研究[J],塑料工业,2005,33(6):45-47
[46]郑红,戚洪彬,梁树干,大学化学实验[M],地质出版社(北京),2005:60-63
[47]印永嘉,奚正楷,李大珍,物理化学简明教程[M],高等教育出版社(北京),1992:436-454
[48]叶振华,化工吸附分离过程[M],中国石化出版社(北京),1992:57-58