桉树遗态Fe/C复合材料对水中Cr(Ⅵ)的动态吸附探讨
|
摘要
为研究桉树遗态Fe/C复合材料(PBGC-Fe/C)对水中Cr(Ⅵ)的净化能力及其动态吸附过程,以PBGC-Fe/C吸附剂为固定床,选择溶液初始p H、进水流速、溶液初始浓度、吸附剂投加量和环境温度为影响因素开展动态吸附试验分析.结果表明:在溶液初始p H为2,进水流速为5.14 m L/min,吸附剂投加量为2 g和环境温度为35℃的条件下,PBGC-Fe/C对水中Cr(Ⅵ)的最佳平衡吸附容量达到10.72 mg/g;提高溶液初始p H、进水流速和溶液初始质量浓度或降低吸附剂投加量均可缩短反应穿透时间和衰竭时间;Thomas和Yoon-Nelson模型均能较好地描述PBGC-Fe/C对水中Cr(Ⅵ)的动态吸附过程,说明该吸附过程中内部扩散和外部扩散均为非限速步骤,吸附速率常数(kTh)随着进水流速的增大从1.3×10-3m L/(min·mg)升至2.6×10-3m L/(min·mg),随着溶液初始质量浓度的增大从2.7×10-3m L/(min·mg)降至1.4×10-3m L/(min·mg).研究显示,PBGC-Fe/C对水中Cr(Ⅵ)具有较好的动态吸附能力,具有较好的市场应用前景.
The column adsorption of Cr( VI) from aqueous solution by the porous biomorph-genetic Fe/C composite prepared with eucalyptus template( PBGC-Fe/C) was experimentally studied. The effects of influent p H,influent flow rate,influent concentration,adsorbent dosage and temperature were examined to investigate the adsorption capacity and mechanism. The results indicated that the PBGC-Fe/C reached the maximum adsorption capacity for Cr( VI) of 10. 72 mg/g under the operating conditions of the flow rate of 5. 14 m L/min,the adsorbent dosage of 2 g and the temperature of 35 ℃ at p H = 2. 0. The increase in the influent p H,flow rate and Cr( VI)concentration or the decrease in the adsorbent dosage resulted in an earlier exhaustion and breakthrough of the PBGC-Fe/C column. The column adsorption breakthrough curves could be well fitted with the Thomas and the Yoon-Nelson models,indicating that the adsorption was not limited by the internal and external diffusion. The adsorption rate constant( kTh) increased from 1. 3×10-3 m L/( min·mg) to 2. 6×10-3 m L/( min·mg) with the increase in the influent flow rate and decreased from 2. 7× 10-3 m L/( min·mg) to 1. 4× 10-3 m L/( min·mg)with the increase in the initial concentration. Consequently,the PBGC-Fe/C with a large capacity for the column adsorption of Cr( VI)from aqueous solution showed a broad application prospect.
The column adsorption of Cr( VI) from aqueous solution by the porous biomorph-genetic Fe/C composite prepared with eucalyptus template( PBGC-Fe/C) was experimentally studied. The effects of influent p H,influent flow rate,influent concentration,adsorbent dosage and temperature were examined to investigate the adsorption capacity and mechanism. The results indicated that the PBGC-Fe/C reached the maximum adsorption capacity for Cr( VI) of 10. 72 mg/g under the operating conditions of the flow rate of 5. 14 m L/min,the adsorbent dosage of 2 g and the temperature of 35 ℃ at p H = 2. 0. The increase in the influent p H,flow rate and Cr( VI)concentration or the decrease in the adsorbent dosage resulted in an earlier exhaustion and breakthrough of the PBGC-Fe/C column. The column adsorption breakthrough curves could be well fitted with the Thomas and the Yoon-Nelson models,indicating that the adsorption was not limited by the internal and external diffusion. The adsorption rate constant( kTh) increased from 1. 3×10-3 m L/( min·mg) to 2. 6×10-3 m L/( min·mg) with the increase in the influent flow rate and decreased from 2. 7× 10-3 m L/( min·mg) to 1. 4× 10-3 m L/( min·mg)with the increase in the initial concentration. Consequently,the PBGC-Fe/C with a large capacity for the column adsorption of Cr( VI)from aqueous solution showed a broad application prospect.
引文
[1]MOHANTY K,JHA M,MEIKAP B C,et al.Removal of chromium(Ⅵ)from dilute aqueous solutions by activated carbon developed from Terminalia arjuna nuts activated with zinc chloride[J].Chemical Engineering Science,2005,60(11):3049-3059.
[2]MOHAMED A,NASSER W S,OSMAN T A,et al.Removal of chromium(Ⅵ)from aqueous solutions using surface modified composite nanofibers[J].Journal of Colloid and Interface Science,2017,505:682-691.
[3]张永利,朱佳,史册,等.高岭土的改性及其对Cr(Ⅵ)的吸附特性[J].环境科学研究,2013,26(5):561-568.ZHANG Yongli,ZHU Jia,SHI Ce,et al.Modification of Kaolin and its adsorption properties on Cr(Ⅵ)[J].Research of Enviromental Sciences,2013,26(5):561-568.
[4]张继义,梁丽萍,蒲丽君,等.小麦秸秆对Cr(Ⅵ)的吸附特性及动力学、热力学分析[J].环境科学研究,2010,23(12):1546-1552.ZHANG Jiyi,LIANG Liping,PU Lijun,et al.Adsorption characteristics of Cr(Ⅵ)by wheat straw including kinetic and thermodynamics analysis[J].Research of Enviromental Sciences,2010,23(12):1546-1552.
[5]HU Jing,CHEN Guohua,LO M C.Removal and recovery of Cr(Ⅵ)from wastewater by maghemite nanoparticles[J].Water Research,2005,39(18):4528-4536.
[6]CHAND R,NARIMURA K,KAWAKITA H,et al.Grape waste as a biosorbent for removing Cr(Ⅵ)from aqueous solution[J].Journal of Hazardous Materials,2009,163(1):245-250.
[7]YANG Shuang,LI Lingyun,PEI Zhiguo,et al.Adsorption kinetics,isotherms and thermodynamics of Cr(III)on graphene oxide[J].Colloids&Surfaces A Physicochemical&Engineering Aspects,2014,457(1):100-106.
[8]LVAREZ A E,GARCA S A,QUEROL X.Purification of metal electroplating waste waters using zeolites[J].Water Research,2003,37(20):4855-4862.
[9]刘新,冷言冰,谷仕艳,等.油菜秸杆外壳对水溶液中六价铬的吸附作用[J].中国环境科学,2015,35(6):1740-1748.LIU Xin,LENG Yanbing,GU Shiyan,et al.Adsorption of Cr(Ⅵ)in the aqueous solution by the rape straw shell powder[J].China Enviromental Science,2015,35(6):1740-1748.
[10]HOKKANEN S,BHATNAGAR A,SILLANPAA M.A review on modification methods to cellulose-based adsorbents to improve adsorption capacity[J].Water Research,2016,91:156-173.
[11]秦泽敏,董黎明,刘平,等.零价纳米铁吸附去除水中六价铬的研究[J].中国环境科学,2014,34(12):3106-3111.QIN Zemin,DONG Liming,LIU Ping,et al.Removal Cr6+from water using nanoscale zero-valent ion[J].China Enviromental Science,2014,34(12):3106-3111.
[12]刘伟,杨琦,李博,等.磁性石墨烯吸附水中Cr(Ⅵ)研究[J].环境科学,2015,36(2):537-544.LIU Wei,YANG Qi,LI Bo,et al.Adsorption of Cr(Ⅵ)on magnetic graphene from aqueous solution[J].Enviromental Science,2015,36(2):537-544.
[13]AVILA M,BURKS T,AKHTAR F,et al.Surface functionalized nanofibers for the removal of chromium(Ⅵ)from aqueous solutions[J].Chemical Engineering Journal,2014,245(2):201-209.
[14]何忠明,王琼,付宏渊,等.柚子皮吸附去除水中的六价Cr和砷[J].环境工程,2016,34(S1):299-302.HE Zhongming,WANG Qiong,FU Hongyuan,et al.Adsorption removal of Cr(Ⅵ)/As in aqueous solution by pomelo peel[J].Environmental Engineering,2016,34(S1):299-302.
[15]谭笑,朱宗强,曹爽,等.桉树遗态结构HAP/C复合材料对水中Cd2+的吸附性能[J].水处理技术,2017(9):38-42.TAN Xiao,ZHU Zongqiang,CAO Shuang,et al.Adsorption characteristics of Cd(Ⅱ)in water by the porous biomorph-genetic composite of HAP/C with eucalyptus wood template[J].Technology of Water Treatment,2017(9):38-42.
[16]李超,朱宗强,曹爽,等.桉树遗态结构HAP/C复合材料对水中Cu(Ⅱ)的吸附特征[J].环境科学,2017,38(3):1074-1083.LI Chao,ZHU Zongqiang,CAO Shuang,et al.Adsorption characteristics of copper in water by the porous biomorph-genetic composite of HAP/C with eucalyptus wood template[J].Enviromental Science,2017,38(3):1074-1083.
[17]朱宗强,朱义年,秦辉,等.一种桉树遗态Fe2O3/Fe3O4复合重金属吸附剂的制备方法:中国,201110133840.1[P].2011-05-20.
[18]THOMAS H C.HETEROGENEOUS,Heterogeneous ion exchange in a flowing system[J].Journal of the American Chemical Society,1944,66(10):1664-1666.
[19]YOON Y H,NELSON J H.Application of gas adsorption kinetics-II.A theoretical model for respirator cartridge service life and its practical applications[J].American Industrial Hygiene Association Journal,1984,45(8):517-524.
[20]AKSU Z,AGˇATAY爦爦,GNEN F.Continuous fixed bed biosorption of reactive dyes by dried Rhizopus arrhizus:determination of column capacity[J].Journal of Hazardous Materials,2007,143(1/2):362-371.
[21]YUSOF A M,MALEK N A N N.Removal of Cr(Ⅵ)and As(V)from aqueous solutions by HDTMA-modified zeolite[J].Journal of Hazardous Materials,2009,162:1019-1024
[22]LUCAS S,CALVO M P,PALENCIA C,et al.Mathematical model of supercritical CO2adsorption on activated carbon:Effect of operating conditions and adsorption scale-up[J].Journal of Supercritical Fluids,2004,32(1):193-201.
[23]PAN B C,MENG F W,CHEN X Q,et al.Application of an effective method in predicting breakthrough curves of fixed-bed adsorption onto resin adsorbent[J].Journal of Hazardous Materials,2005,124(1/2/3):74-80.
[24]王喜,邓圣,张广山,等.新型螯合纤维对含铜废水的动态吸附及模型研究[C]//中国环境科学学会.中国环境科学学会学术年会光大环保优秀论文集.第一卷.北京:中国环境科学,2015:35-42.
[25]孔郑磊,李晓晨,杨继利,等.改性荔枝皮对水中Pb(Ⅱ)的动态吸附特性[J].环境科学研究,2014,27(10):1186-1192.KONG Zhenglei,LI Xiaochen,YANG Jili,et al.Biosorption of Pb(Ⅱ)by modified lychee pericarps in fixed-bed columns[J].Research of Enviromental Sciences,2014,27(10):1186-1192.
[26]胡奇,李玉立,潘红玉,等.改性木屑对水中苯胺的动态吸附[J].环境工程学报,2016,10(9):4663-4667.HU Qi,LI Yuli,PAN Yuhong,et al.Dynamic adsorption of aniline in water on modified sawdust[J].Chinese Journal of Environmental Engineering,2016,10(9):4663-4667.
[2]MOHAMED A,NASSER W S,OSMAN T A,et al.Removal of chromium(Ⅵ)from aqueous solutions using surface modified composite nanofibers[J].Journal of Colloid and Interface Science,2017,505:682-691.
[3]张永利,朱佳,史册,等.高岭土的改性及其对Cr(Ⅵ)的吸附特性[J].环境科学研究,2013,26(5):561-568.ZHANG Yongli,ZHU Jia,SHI Ce,et al.Modification of Kaolin and its adsorption properties on Cr(Ⅵ)[J].Research of Enviromental Sciences,2013,26(5):561-568.
[4]张继义,梁丽萍,蒲丽君,等.小麦秸秆对Cr(Ⅵ)的吸附特性及动力学、热力学分析[J].环境科学研究,2010,23(12):1546-1552.ZHANG Jiyi,LIANG Liping,PU Lijun,et al.Adsorption characteristics of Cr(Ⅵ)by wheat straw including kinetic and thermodynamics analysis[J].Research of Enviromental Sciences,2010,23(12):1546-1552.
[5]HU Jing,CHEN Guohua,LO M C.Removal and recovery of Cr(Ⅵ)from wastewater by maghemite nanoparticles[J].Water Research,2005,39(18):4528-4536.
[6]CHAND R,NARIMURA K,KAWAKITA H,et al.Grape waste as a biosorbent for removing Cr(Ⅵ)from aqueous solution[J].Journal of Hazardous Materials,2009,163(1):245-250.
[7]YANG Shuang,LI Lingyun,PEI Zhiguo,et al.Adsorption kinetics,isotherms and thermodynamics of Cr(III)on graphene oxide[J].Colloids&Surfaces A Physicochemical&Engineering Aspects,2014,457(1):100-106.
[8]LVAREZ A E,GARCA S A,QUEROL X.Purification of metal electroplating waste waters using zeolites[J].Water Research,2003,37(20):4855-4862.
[9]刘新,冷言冰,谷仕艳,等.油菜秸杆外壳对水溶液中六价铬的吸附作用[J].中国环境科学,2015,35(6):1740-1748.LIU Xin,LENG Yanbing,GU Shiyan,et al.Adsorption of Cr(Ⅵ)in the aqueous solution by the rape straw shell powder[J].China Enviromental Science,2015,35(6):1740-1748.
[10]HOKKANEN S,BHATNAGAR A,SILLANPAA M.A review on modification methods to cellulose-based adsorbents to improve adsorption capacity[J].Water Research,2016,91:156-173.
[11]秦泽敏,董黎明,刘平,等.零价纳米铁吸附去除水中六价铬的研究[J].中国环境科学,2014,34(12):3106-3111.QIN Zemin,DONG Liming,LIU Ping,et al.Removal Cr6+from water using nanoscale zero-valent ion[J].China Enviromental Science,2014,34(12):3106-3111.
[12]刘伟,杨琦,李博,等.磁性石墨烯吸附水中Cr(Ⅵ)研究[J].环境科学,2015,36(2):537-544.LIU Wei,YANG Qi,LI Bo,et al.Adsorption of Cr(Ⅵ)on magnetic graphene from aqueous solution[J].Enviromental Science,2015,36(2):537-544.
[13]AVILA M,BURKS T,AKHTAR F,et al.Surface functionalized nanofibers for the removal of chromium(Ⅵ)from aqueous solutions[J].Chemical Engineering Journal,2014,245(2):201-209.
[14]何忠明,王琼,付宏渊,等.柚子皮吸附去除水中的六价Cr和砷[J].环境工程,2016,34(S1):299-302.HE Zhongming,WANG Qiong,FU Hongyuan,et al.Adsorption removal of Cr(Ⅵ)/As in aqueous solution by pomelo peel[J].Environmental Engineering,2016,34(S1):299-302.
[15]谭笑,朱宗强,曹爽,等.桉树遗态结构HAP/C复合材料对水中Cd2+的吸附性能[J].水处理技术,2017(9):38-42.TAN Xiao,ZHU Zongqiang,CAO Shuang,et al.Adsorption characteristics of Cd(Ⅱ)in water by the porous biomorph-genetic composite of HAP/C with eucalyptus wood template[J].Technology of Water Treatment,2017(9):38-42.
[16]李超,朱宗强,曹爽,等.桉树遗态结构HAP/C复合材料对水中Cu(Ⅱ)的吸附特征[J].环境科学,2017,38(3):1074-1083.LI Chao,ZHU Zongqiang,CAO Shuang,et al.Adsorption characteristics of copper in water by the porous biomorph-genetic composite of HAP/C with eucalyptus wood template[J].Enviromental Science,2017,38(3):1074-1083.
[17]朱宗强,朱义年,秦辉,等.一种桉树遗态Fe2O3/Fe3O4复合重金属吸附剂的制备方法:中国,201110133840.1[P].2011-05-20.
[18]THOMAS H C.HETEROGENEOUS,Heterogeneous ion exchange in a flowing system[J].Journal of the American Chemical Society,1944,66(10):1664-1666.
[19]YOON Y H,NELSON J H.Application of gas adsorption kinetics-II.A theoretical model for respirator cartridge service life and its practical applications[J].American Industrial Hygiene Association Journal,1984,45(8):517-524.
[20]AKSU Z,AGˇATAY爦爦,GNEN F.Continuous fixed bed biosorption of reactive dyes by dried Rhizopus arrhizus:determination of column capacity[J].Journal of Hazardous Materials,2007,143(1/2):362-371.
[21]YUSOF A M,MALEK N A N N.Removal of Cr(Ⅵ)and As(V)from aqueous solutions by HDTMA-modified zeolite[J].Journal of Hazardous Materials,2009,162:1019-1024
[22]LUCAS S,CALVO M P,PALENCIA C,et al.Mathematical model of supercritical CO2adsorption on activated carbon:Effect of operating conditions and adsorption scale-up[J].Journal of Supercritical Fluids,2004,32(1):193-201.
[23]PAN B C,MENG F W,CHEN X Q,et al.Application of an effective method in predicting breakthrough curves of fixed-bed adsorption onto resin adsorbent[J].Journal of Hazardous Materials,2005,124(1/2/3):74-80.
[24]王喜,邓圣,张广山,等.新型螯合纤维对含铜废水的动态吸附及模型研究[C]//中国环境科学学会.中国环境科学学会学术年会光大环保优秀论文集.第一卷.北京:中国环境科学,2015:35-42.
[25]孔郑磊,李晓晨,杨继利,等.改性荔枝皮对水中Pb(Ⅱ)的动态吸附特性[J].环境科学研究,2014,27(10):1186-1192.KONG Zhenglei,LI Xiaochen,YANG Jili,et al.Biosorption of Pb(Ⅱ)by modified lychee pericarps in fixed-bed columns[J].Research of Enviromental Sciences,2014,27(10):1186-1192.
[26]胡奇,李玉立,潘红玉,等.改性木屑对水中苯胺的动态吸附[J].环境工程学报,2016,10(9):4663-4667.HU Qi,LI Yuli,PAN Yuhong,et al.Dynamic adsorption of aniline in water on modified sawdust[J].Chinese Journal of Environmental Engineering,2016,10(9):4663-4667.