硝基苯在砂性介质中的穿透试验研究
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摘要
本文在承担自然科学基金项目“河流污染对地下水影响的模拟与研究(40872163)的背景下,选择渭河河漫滩砂性介质为研究对象,对特征污染物硝基苯在砂性介质中的穿透试验开展了系统的研究。
采用室内试验与数值模拟相结合的方法,深入探讨硝基苯在砂性介质中穿透的内在规律,揭示穿透过程中砂性介质对硝基苯的吸附行为特征,以质量守恒为理论基础修正穿透曲线模型,并分析模型的影响因素(浓度、流量、穿透高度和穿透介质),结果表明：
1.根据Yoon-Neison理论在硝基苯在砂性介质的穿透曲线中算得的平衡吸附容量夸大了介质的吸附能力,特别在此次的8组穿透试验中,夸大了2.6-6.3倍。
2.本次研究,根据穿透曲线特征和砂柱的吸附特征,将硝基苯在砂柱中的吸附过程分为四个阶段。若将砂柱看成一个单位,在穿透试验中,砂柱对硝基苯的吸附量变化过程类似于一条穿透曲线。从0时刻开始发生吸附,随着试验的进行,t时刻的吸附量逐渐增大,在某一时刻达到最大,而后逐渐减小随着穿透试验的完成归于0。
3.根据本次试验选用模型的拟合结果分析：单一的根据硝基苯的穿透试验来拟合穿透曲线,有时会遇到砂柱发生解吸作用,显然与事实相反,而通过修正后的模型能较好的反应客观事实。在修正过程中,先判断原模型所求结果是否满足3.3.2中的i、ii条件：如果满足模型不需要修正；如果不满足模型需要修正。
4.在此次试验中,分析得到试验的浓度范围内浓度对穿透模型的影响不大,因此忽略了浓度对模型的影响。在同一浓度下,介质的平衡吸附量随穿透高度的增加而增大；细砂的吸附能力大于中砂的吸附能力。
5.根据本次试验研究结果并结合前人成果,总结出穿透试验能够获取的三个参数：弥散系数、吸附和饱及饱和含水率。其中所介绍的平衡吸附容量、吸附系数和饱和含水率是本次研究中发掘的成果。根据试验数据求得试验介质细砂和中砂的弥散系数分别为：1.75cm2/min、7.16cm2/min；弥散度分别为：1.372cm、0.813cm；吸附系数分别为0.189和0.153；饱和含水率分别为42.15%和40.53%。
Based on the background of the nature science fund "Modeling and research of the effects of river pollution on ground water",sand medium of the Wei river is selected to be the study object,and the systematic study on nitrobenzene breakthrough experimental in sand medium is launched.
Using the way combining laboratory experiment and numerical simulation to In-depth study the Internal law nitrobenzene penetrating in sand medium and reveal through the process of sand of medium on adsorption characteristics of nitrobenzene and modified the model of the breakthrough curve to the theoretical basis of mass conservation and analysis model parameters on the sensitivity factors (Concentration, flow, penetration height and penetration media), the results show that:
1.The equilibrium adsorption capacity of the nitrobenzene in the sand medium calculated according to the Yoon-Neison theory is exaggerated,particularly in the 8 groups through this experiment,about 2.6-6.3 times.
2.According to the breakthrough curves and the adsorption characteristics of sand column,the adsorption process of the nitrobenzene in the sand column is divided into four stages.In the breakthrough experiment,the change of the nitrobenzene adsorption process of the sand column is similar to a breakthrough curve if we see sand columns as a unit.The adsorption began from the beginning,and increased to a maximum at some time,then decreased to 0 as the completion of the breakthrough experiment.
3.According to analysis of fitting results used in this experiment,to fit the breakthrough curves only by the breakthrough experiment of nitrobenzene sometimes encountered in sand column desorption which is clearly contray to the facts,but the modified model can response to the objective facts better.In the amendment process,we need determine whether the results of the original model fit the conditions ofⅰ,ⅱof 3.3.2 or not.If it does,the amendment is not required;if not,the model needs to be amended.
4.In this experiment,concentration in the experimental concentration range has little effect on the penetration model,so we can ignore the effect of concentration to the model.In the same concentration,the equilibrium adsorption capacity of the medium increases with the height of the penetration;the adsorption capacity of fine sand is bigger than the medium sand's.
5.According to the results of this study with the previous results,three parameters can obtained from the breakthrough experiment:diffusion coefficient,adsorption coefficient and saturated water content.The equilibrium adsorption capacity,adsorption coefficient and saturated water content is the result of this study.The diffusion coefficients of the fine sand and medium sand are 1.75cm2/min、7.16cm2/min;the dispersions are 1.372cm,0.813cm;the adsorption coefficients are 0.189 and 0.153;and the saturated water content are 42.15% and 40.53%.
采用室内试验与数值模拟相结合的方法,深入探讨硝基苯在砂性介质中穿透的内在规律,揭示穿透过程中砂性介质对硝基苯的吸附行为特征,以质量守恒为理论基础修正穿透曲线模型,并分析模型的影响因素(浓度、流量、穿透高度和穿透介质),结果表明：
1.根据Yoon-Neison理论在硝基苯在砂性介质的穿透曲线中算得的平衡吸附容量夸大了介质的吸附能力,特别在此次的8组穿透试验中,夸大了2.6-6.3倍。
2.本次研究,根据穿透曲线特征和砂柱的吸附特征,将硝基苯在砂柱中的吸附过程分为四个阶段。若将砂柱看成一个单位,在穿透试验中,砂柱对硝基苯的吸附量变化过程类似于一条穿透曲线。从0时刻开始发生吸附,随着试验的进行,t时刻的吸附量逐渐增大,在某一时刻达到最大,而后逐渐减小随着穿透试验的完成归于0。
3.根据本次试验选用模型的拟合结果分析：单一的根据硝基苯的穿透试验来拟合穿透曲线,有时会遇到砂柱发生解吸作用,显然与事实相反,而通过修正后的模型能较好的反应客观事实。在修正过程中,先判断原模型所求结果是否满足3.3.2中的i、ii条件：如果满足模型不需要修正；如果不满足模型需要修正。
4.在此次试验中,分析得到试验的浓度范围内浓度对穿透模型的影响不大,因此忽略了浓度对模型的影响。在同一浓度下,介质的平衡吸附量随穿透高度的增加而增大；细砂的吸附能力大于中砂的吸附能力。
5.根据本次试验研究结果并结合前人成果,总结出穿透试验能够获取的三个参数：弥散系数、吸附和饱及饱和含水率。其中所介绍的平衡吸附容量、吸附系数和饱和含水率是本次研究中发掘的成果。根据试验数据求得试验介质细砂和中砂的弥散系数分别为：1.75cm2/min、7.16cm2/min；弥散度分别为：1.372cm、0.813cm；吸附系数分别为0.189和0.153；饱和含水率分别为42.15%和40.53%。
Based on the background of the nature science fund "Modeling and research of the effects of river pollution on ground water",sand medium of the Wei river is selected to be the study object,and the systematic study on nitrobenzene breakthrough experimental in sand medium is launched.
Using the way combining laboratory experiment and numerical simulation to In-depth study the Internal law nitrobenzene penetrating in sand medium and reveal through the process of sand of medium on adsorption characteristics of nitrobenzene and modified the model of the breakthrough curve to the theoretical basis of mass conservation and analysis model parameters on the sensitivity factors (Concentration, flow, penetration height and penetration media), the results show that:
1.The equilibrium adsorption capacity of the nitrobenzene in the sand medium calculated according to the Yoon-Neison theory is exaggerated,particularly in the 8 groups through this experiment,about 2.6-6.3 times.
2.According to the breakthrough curves and the adsorption characteristics of sand column,the adsorption process of the nitrobenzene in the sand column is divided into four stages.In the breakthrough experiment,the change of the nitrobenzene adsorption process of the sand column is similar to a breakthrough curve if we see sand columns as a unit.The adsorption began from the beginning,and increased to a maximum at some time,then decreased to 0 as the completion of the breakthrough experiment.
3.According to analysis of fitting results used in this experiment,to fit the breakthrough curves only by the breakthrough experiment of nitrobenzene sometimes encountered in sand column desorption which is clearly contray to the facts,but the modified model can response to the objective facts better.In the amendment process,we need determine whether the results of the original model fit the conditions ofⅰ,ⅱof 3.3.2 or not.If it does,the amendment is not required;if not,the model needs to be amended.
4.In this experiment,concentration in the experimental concentration range has little effect on the penetration model,so we can ignore the effect of concentration to the model.In the same concentration,the equilibrium adsorption capacity of the medium increases with the height of the penetration;the adsorption capacity of fine sand is bigger than the medium sand's.
5.According to the results of this study with the previous results,three parameters can obtained from the breakthrough experiment:diffusion coefficient,adsorption coefficient and saturated water content.The equilibrium adsorption capacity,adsorption coefficient and saturated water content is the result of this study.The diffusion coefficients of the fine sand and medium sand are 1.75cm2/min、7.16cm2/min;the dispersions are 1.372cm,0.813cm;the adsorption coefficients are 0.189 and 0.153;and the saturated water content are 42.15% and 40.53%.
引文
[1]中国地质调查局.中国国土资源公报,北京,2004.
[2]中国地质调查局.中国地质环境公报,北京,2007.
[3]吕贤弼.地下水污染的根源及防治闭.中国水利,1999,(3)：35-42.
[4]中国国家环保总局.松花江水污染情况通报.北京,2005.
[5]Bohart G, Adams EQ.Some aspects of the behavior of charcoal with respect to chlorine. J Am Chem Soc 1920;42:523-44.
[6]Thomas HC.Heterogeneous ion exchange in a flowing system[J].J Am Chem Soc 1944;66:1664-6.
[7]Clark RM.Evaluating the cost and performance of field-scale granular activated carbon systems[J].Environ Sci Technol 1987;21:573-80.
[8]Yoon YH, Nelson JH. Aplication of gas adsorption kinetics. I. A theoretical model for respirator cartridge service time. Am Ind Hyg Assoc J 1984;45:509-16.
[9]陈占营,王旭辉,等.在氙活性炭纤维吸附床上穿透的动力学模型[J].无机化学学报.2008 vol.24 no.3 351-356
[10]孙晓峰,高乃云,等.邻苯二甲酸二甲酯在颗粒活性炭中的穿透特性[J].2007环境科学Vol.28,No.8 1738-1745
[11]Li Wang Ma, H M Selim. Transport a nonreactive solute in soils:a two-flow domain approach[J].Soil Science.America 1995 159(4):224-234.
[12]J. Skopp, W.R. Gardner,E.J. Tyler,1981 Solute Movement in Structured Soils: Two-Region Model with Small Interaction Published in Soil Sci Soc Am J 45:837-842 (1981)
[13]马东豪,王全九.土壤溶质迁移的两区模型与两流区模型对比分析[J].2004.水利学报.Vol.6 1-8
[14]Jury, W.A.,Gardner, W.R.,Gardner, W.H.,1991.Soil Physics, fifth ed.John Wiley and Sons Inc, New York.
[15]Tseng, P.H.,Jury, W.A.,1994. Comparison of transfer function and deterministic modeling of area-averaged solute transport in a heterogeneous field. Water Resources Research 30,2051-2063.
[16]Jury, W.A.,1982.Simulation of solute transport using transfer function model. Water Resources Research 18,363-368.
[17]Jury, W.A.,Sposito, G,1986. A transfer function of solute transport through soil 1. Fundamental concepts.Water Resources Research 22,243-247.
[18]White, R.E.,Dyson, J.S.,Haigh, R.A.,Jury, W.A.,1986.A transfer function model of solute transport through soil 2.Illustrative applications.Water Resources Research 22, 248-254.
[19]Butters, G.L., Jury, W.A.,1989. Field scale transport of bromide in an unsaturated soil,2.Dispersion modeling. Water Resources Research 25,1583-1589.
[20]Skaggs, T.H.,Kabala, Z.J.,Jury, W.A.,1998.Deconvolution of a nonparametric transfer function for solute transport in soils.Journal of Hydrology 207,170-178.
[21]Heesung Yoon, Yunjung Hyun, Kang-Kun Lee.Forecasting solute breakthrough curves through the unsaturated zone using artificial neural rietworks. Journal of Hydrology (2007)335,68-77
[22]陈效民,潘根兴,等.太湖地区农田土壤中硝态氮垂直运移的规律中国环境科2001,21(6)：481～484
[23]Jia-Ming Chern,Yi-Wen Chien.Adsorption of nitrophenol onto activated carbon:isotherms and breakthrough curves.Water Research 36 (2002) 647-655
[24]B.C.Pan et al Application of an effective method in predicting breakthrough curves of fixed-bed adsorption onto resin adsorbent Journal of Hazardous Materials B124 (2005) 74-80
[25]杨骏,秦张峰,等.穿透曲线法获取固定床吸附器的传质扩散系数[J].化学工程1996 Vol.24,No.618-20
[26]Wolborska A. Adsorption on activated carbon of p-nitrophenol from aqueous solution[J].Water Res 1989;23:85-91.
[27]Rao JR, Viraraghavan T. Biosorption of phenol from a aqueous solution by Aspergillus niger biomass. Bioresour Technol[J] 2002;85:165-71.
[28]Tran HH, Roddick FA. Comparison of chromatography and desiccant silica gels for the adsorption of metal ions[J].Water Res 1999;33:3001-11.
[29]Zumriye Aksu□, Ferda Gone. Biosorption of phenol by immobilized activated sludge in a continuous packed bed:prediction of breakthrough curves[J].Process Biochemistry 39 (2004) 599-613
[30]Li Wang Ma, H M Selim. Transport a nonreactive solute in soils:a two-flow domain approach[J].Soil Science.America 1995 159(4):224-234.
[31]Butters, G.L.,Jury, W.A.,Ernst, F.F.,1989. Field scale transport of bromide in an unsaturated soil,1.Experimental methodology and results. Water Resource Research 25, 1575-1581.
[32]Zealand, C.M.,Burn, D.H.,Simonovic, S.P.,1999.Short term streamflow forecasting using artificial neural networks.Journal of Hydrology 214,32-48.
[33]Sharma, V.,Negi, S.C.,Rudra, R.P.,Yang, S.,2003.Neural networks for predicting nitrate-nitrogen in drainage water. Agricultural Water Management 63,169-183.
[34]钱会,马致远.水文地球化学[M].地质出版社,北京,2005..
[35]Sushil K.Singh. Estimating dispersivity and injected mass from breakthrough curve due to instantaneous source. Journal of Hydrology (2006) 329,685-691.
[36]Sushil K.Singh.Estimating Dispersion Coefficient and Porosity from Soil-Column Tests[J]Journal of Environmental Engineering(2002):1095-1099.
[37]Jean Pierre Sauty.An Analysis of Hydrodispersive Transfer in Aquifers[J].Water Resources Research,1980,Vol.16,No.1:145-15.
[38]张文静.佳木斯地区地下水、土中硝基苯迁移转化机理及其模拟预测[D].吉林大学,2007.
[2]中国地质调查局.中国地质环境公报,北京,2007.
[3]吕贤弼.地下水污染的根源及防治闭.中国水利,1999,(3)：35-42.
[4]中国国家环保总局.松花江水污染情况通报.北京,2005.
[5]Bohart G, Adams EQ.Some aspects of the behavior of charcoal with respect to chlorine. J Am Chem Soc 1920;42:523-44.
[6]Thomas HC.Heterogeneous ion exchange in a flowing system[J].J Am Chem Soc 1944;66:1664-6.
[7]Clark RM.Evaluating the cost and performance of field-scale granular activated carbon systems[J].Environ Sci Technol 1987;21:573-80.
[8]Yoon YH, Nelson JH. Aplication of gas adsorption kinetics. I. A theoretical model for respirator cartridge service time. Am Ind Hyg Assoc J 1984;45:509-16.
[9]陈占营,王旭辉,等.在氙活性炭纤维吸附床上穿透的动力学模型[J].无机化学学报.2008 vol.24 no.3 351-356
[10]孙晓峰,高乃云,等.邻苯二甲酸二甲酯在颗粒活性炭中的穿透特性[J].2007环境科学Vol.28,No.8 1738-1745
[11]Li Wang Ma, H M Selim. Transport a nonreactive solute in soils:a two-flow domain approach[J].Soil Science.America 1995 159(4):224-234.
[12]J. Skopp, W.R. Gardner,E.J. Tyler,1981 Solute Movement in Structured Soils: Two-Region Model with Small Interaction Published in Soil Sci Soc Am J 45:837-842 (1981)
[13]马东豪,王全九.土壤溶质迁移的两区模型与两流区模型对比分析[J].2004.水利学报.Vol.6 1-8
[14]Jury, W.A.,Gardner, W.R.,Gardner, W.H.,1991.Soil Physics, fifth ed.John Wiley and Sons Inc, New York.
[15]Tseng, P.H.,Jury, W.A.,1994. Comparison of transfer function and deterministic modeling of area-averaged solute transport in a heterogeneous field. Water Resources Research 30,2051-2063.
[16]Jury, W.A.,1982.Simulation of solute transport using transfer function model. Water Resources Research 18,363-368.
[17]Jury, W.A.,Sposito, G,1986. A transfer function of solute transport through soil 1. Fundamental concepts.Water Resources Research 22,243-247.
[18]White, R.E.,Dyson, J.S.,Haigh, R.A.,Jury, W.A.,1986.A transfer function model of solute transport through soil 2.Illustrative applications.Water Resources Research 22, 248-254.
[19]Butters, G.L., Jury, W.A.,1989. Field scale transport of bromide in an unsaturated soil,2.Dispersion modeling. Water Resources Research 25,1583-1589.
[20]Skaggs, T.H.,Kabala, Z.J.,Jury, W.A.,1998.Deconvolution of a nonparametric transfer function for solute transport in soils.Journal of Hydrology 207,170-178.
[21]Heesung Yoon, Yunjung Hyun, Kang-Kun Lee.Forecasting solute breakthrough curves through the unsaturated zone using artificial neural rietworks. Journal of Hydrology (2007)335,68-77
[22]陈效民,潘根兴,等.太湖地区农田土壤中硝态氮垂直运移的规律中国环境科2001,21(6)：481～484
[23]Jia-Ming Chern,Yi-Wen Chien.Adsorption of nitrophenol onto activated carbon:isotherms and breakthrough curves.Water Research 36 (2002) 647-655
[24]B.C.Pan et al Application of an effective method in predicting breakthrough curves of fixed-bed adsorption onto resin adsorbent Journal of Hazardous Materials B124 (2005) 74-80
[25]杨骏,秦张峰,等.穿透曲线法获取固定床吸附器的传质扩散系数[J].化学工程1996 Vol.24,No.618-20
[26]Wolborska A. Adsorption on activated carbon of p-nitrophenol from aqueous solution[J].Water Res 1989;23:85-91.
[27]Rao JR, Viraraghavan T. Biosorption of phenol from a aqueous solution by Aspergillus niger biomass. Bioresour Technol[J] 2002;85:165-71.
[28]Tran HH, Roddick FA. Comparison of chromatography and desiccant silica gels for the adsorption of metal ions[J].Water Res 1999;33:3001-11.
[29]Zumriye Aksu□, Ferda Gone. Biosorption of phenol by immobilized activated sludge in a continuous packed bed:prediction of breakthrough curves[J].Process Biochemistry 39 (2004) 599-613
[30]Li Wang Ma, H M Selim. Transport a nonreactive solute in soils:a two-flow domain approach[J].Soil Science.America 1995 159(4):224-234.
[31]Butters, G.L.,Jury, W.A.,Ernst, F.F.,1989. Field scale transport of bromide in an unsaturated soil,1.Experimental methodology and results. Water Resource Research 25, 1575-1581.
[32]Zealand, C.M.,Burn, D.H.,Simonovic, S.P.,1999.Short term streamflow forecasting using artificial neural networks.Journal of Hydrology 214,32-48.
[33]Sharma, V.,Negi, S.C.,Rudra, R.P.,Yang, S.,2003.Neural networks for predicting nitrate-nitrogen in drainage water. Agricultural Water Management 63,169-183.
[34]钱会,马致远.水文地球化学[M].地质出版社,北京,2005..
[35]Sushil K.Singh. Estimating dispersivity and injected mass from breakthrough curve due to instantaneous source. Journal of Hydrology (2006) 329,685-691.
[36]Sushil K.Singh.Estimating Dispersion Coefficient and Porosity from Soil-Column Tests[J]Journal of Environmental Engineering(2002):1095-1099.
[37]Jean Pierre Sauty.An Analysis of Hydrodispersive Transfer in Aquifers[J].Water Resources Research,1980,Vol.16,No.1:145-15.
[38]张文静.佳木斯地区地下水、土中硝基苯迁移转化机理及其模拟预测[D].吉林大学,2007.