INVESTIGATION OF A LYSIMETER USING THE SIMULATION TOOL SiWaPro DSS AND ADAPTATION OF THIS PROGRAM TO VIETNAMESE REQUIREMENTS

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1 HANOI UNIVERSITY OF SCIENCE TECHNICAL UNIVERSITAT DRESDEN PHAM THI BICH NGOC INVESTIGATION OF A LYSIMETER USING THE SIMULATION TOOL SiWaPro DSS AND ADAPTATION OF THIS PROGRAM TO VIETNAMESE REQUIREMENTS MASTER THESIS Tutor: Prof. Dr. Ing. habil Peter Wolfgang Graeber Dipl. Ing. Rene Blankenburg Technical University Dresden Institute of Waste Management and Contaiminated Site Treatment HANOI – VIETNAM, DECEMBER 2008 2 TECHNISCHE UNIVERSITÄT DRESDEN INSTITUTE OF WASTE MANAGEMENT AND CONTAMINATED SITE TREATMENT Master Thesis Pollutant mixtures: Investigation of resulting changes in the single compounds water solubility Supervisor: Dipl.-Ing. Dipl.-Ing. Jens Fahl TU Dresden, Institute for Waste Management and Contaminated Site Treatment Hanoi, 2008. 3 Acknowledgment First of all, I would like to express my thankfulness for Jens Fahl, my supervisor for your knowledge and enthusiasm. Without your encouragement and advice I can not complete this work. I also gratefully acknowledge Dr. Axel Fischer for all you have done for me. Special thanks for Marene, you are very kind and patient for me. Thanks for Stefan, Claudia, I'm very grateful for your support. I would like to thank Prof. Dr. Bilitewski, Prof. Dr. Nguyen Thi Diem Trang and Assc. Prof. Dr. Bui Duy Cam for great effort to establish and develop this program. I also would like express my gratitude to the following organizations for supporting me throughout the course - The Committee on Overseas Training Project- Ministry of Education and Training of Vietnam - Hanoi University of Science - Vietnam National University - Institute for Waste Management and Contaminated Site Treatment – TU Dresden - German Academic Exchange Service (DAAD) Warmly thanks to Mai, Christian, Hai Minh for your help. Thanks to all my colleagues who shared a good time with me. Finally, thanks to my family, my parent, my mother in law, my husband and my little son who always along with me, encourage and share difficulties and pleasure as well. Hanoi, 10th December, 2008. Vu Huyen Phuong 4 Table of contents Acknowledgment ............................................................................................................. 3 Table of contents ............................................................................................................. 4 Abbreviations .................................................................................................................. 6 Figures and pictures ....................................................................................................... 7 Tables ............................................................................................................................... 8 Summary ........................................................................................................................ 10 1. INTRODUCTION................................................................................................. 11 1.1 Some important definition related to solubility ............................................... 16 1.2 Factors influencing solubility .......................................................................... 17 1.2.1 Temperature effects: ................................................................................. 17 1.2.2 Pressure effects ......................................................................................... 19 1.2.3 Salting out effect ....................................................................................... 20 1.2.4 Cosolvent effects ....................................................................................... 20 1.3 Estimation of solubility ..................................................................................... 21 2 MATERIALS AND METHODS ......................................................................... 27 2.1 Materials ........................................................................................................... 27 2.2 Experimental procedure .................................................................................... 30 2.3 Analyzing method ............................................................................................. 33 2.3.1 Ethylbenzene and Toluene ........................................................................ 33 2.3.2 Anthracene and Naphthalene .................................................................... 33 2.3.3 Phenol ....................................................................................................... 34 2.3.4 Tetradecane ............................................................................................... 34 2.4 Assessment of experimental data ...................................................................... 37 3. RESULTS AND DISCUSSIONS ............................................................................. 39 3.1. Preliminary experiments ................................................................................... 39 3.2. Water solubility of studied organic compounds in pure form .......................... 45 3.2.1. Solubility of Ethylbenzene in water .......................................................... 46 3.2.2. Solubility of Phenol in water .................................................................... 50 3.2.3. Solubility of Anthracene and Naphthalene in water ................................. 52 3.3. Water solubility of studied organic compound mixtures .................................. 55 3.3.1. Mixture of Ethylbenzene and Toluene ...................................................... 56 3.3.2. Mixture of Ethylbenzene and Phenol ........................................................ 58 3.3.3. Ethylbenzene – Anthracene – Naphthalene Mixture ................................ 60 3.3.4. Ethylbenzene – Toluene - Anthracene – Naphthalene Mixture ............... 61 5 4. 3.3.5. Phenol - Tetradecane Mixture; Naphthalene – Tetradecane Mixture and Special Mixture ......................................................................................................... 64 PROSPECT ........................................................................................................... 66 5. CONCLUSIONS ................................................................................................... 67 6. References .............................................................................................................. 68 7. Statement under oath ........................................................................................... 71 8. Appendix ................................................................................................................ 72 6 Abbreviations HOC: Hydrophobic Organic Chemical PMOS: Partially Miscible Organic Solvent. IUPAC: International Union for Pure and Applied Chemistry VOC: Volatile Organic Compound PAH: Polycyclic Aromatic Hydrocarbon UNIFAC: Universal Quasi Chemical Functional Group Activity Coefficient BTEX: Benzene – Toluene – Ethylbenzene – Xylene GC: Gas Chromatograph HPLC: High Performance Liquid Chromatograph 7 Figures and pictures Figure 1: Ranges in water solubility of some organic compound classes Figure 2: Water solubility as a function of temperature Figure 3: Experimental and predicted value for mixture ethanol – cyclohexane Figure 4: Ethylbenzene concentrations in aqueous phase of three time sampling Figure 5: Anthracene concentrations in aqueous phase of two time sampling Figure 6: Comparison of water solubility of Ethylbenzene in different temperature Figure 7: Comparison of water solubility of Toluene in different temperature Figure 8: Comparison of water solubility of Phenol in different temperature Figure 9: Solubility of Anthracene in water of selected data 10 18 25 Picture 1: Glass vial 20ml with special silicone septum Picture 2: Glass vessel 100ml with special rubber cap Picture 3: Glass vessel 500ml with special rubber cap Picture 4: Samples is kept at 20oC Picture 5: Store samples in room 5oC Picture 6: Store samples in room 10oC Picture 7: Taking sample by microliter syringe 50μl Picture 8: Taking sample by syringe 2ml Picture 9: Preparation sample for GC/headspace Picture 10: Preparation sample for HPLC Picture 11: GC/headspace Picture 12: GC System Picture 13: Spectrometer Picture 14: HPLC System Picture 15: Experiment to determine stirring needed or not to get maximum solubility 29 29 30 31 32 32 32 32 36 36 36 36 36 36 41 42 43 47 50 51 53 8 Tables Table 1: Chemical/physical properties of selected substances in this work 12 Table 2: Difference of solubility in different temperature 19 Table 3: Effect of pressure on the solubility of Xylene 19 Table 4: Purity of studied substances 28 Table 5: Concentration of Ethylbenzene and Anthracene at different times 39 Table 6: Ethylbenzene concentrations (mg/l) in stirring and non-stirring condition 41 Table 7: Anthracene concentrations (μg/l) in stirring and non-stirring condition 41 Table 8: Solubility of Ethylbenzene at different temperature (mg/l) 46 Table 9: Comparison of experimental data and literature data of Ethylbenzene 46 Table 10: Solubility of Toluene at different temperature (mg/l) 48 Table 11: Comparison of experimental data and literature data of Toluene 48 Table 12: Solubility of Phenol at different temperature (mg/l) 50 Table 13: Average value of phenol solubility in water 51 Table 14: Solubility of Naphthalene and Anthracene at 20oC 52 o Table 15: Comparison of experimental data and literature data of Antharacene at 20 C 52 Table 14: Comparison between experimental data and literature data of Naphthalene at 54 20oC Table 15: Aqueous concentration of Ethylbenzene and Toluene in their mixture at 56 20oC Table 16: Aqueous concentration of Ethylbenzene and Toluene in their mixture at 5oC 57 Table 17: Comparison of experimental and calculated solubility of Ethylbezene and 58 Toluene at 20oC Table 18: Aqueous concentration of Ethylbenzene and Phenol in their mixture at 20oC 59 Table 19: Aqueous concentration of Ethylbenzene and Phenol in their mixture at 5oC 59 Table 20: Aqueous concentration of Ethylbenzene – Anthracene – Naphthalene in the 60 o mixture at 20 C Table 21: Aqueous concentration of Ethylbenzene – Anthracene – Naphthalene in the mixture at 5oC 60 9 Table 22: Accuracy of experimental values for components in the mixture 61 Ethylbenzene – Anthracene – Naphthalene Table 23: Aqueous concentration of Ethylbenzene – Toluene - Anthracene – 62 o Naphthalene in the mixture at 20 C Table 24: Aqueous concentration of Ethylbenzene – Toluene - Anthracene – 62 Naphthalene in the mixture at 5oC Table 25: Accuracy of experimental values of component of mixture Ethylbenzene – 63 Anthracene – Naphthalene Table 26: Comparison of experimental and calculated solubility of each component in 63 o mixture Ethylbenzene – Toluene - Anthracene – Naphthalene at 5 C Table 27: Aqueous concentration of components of the mixture Phenol - Tetradecane 65 and Naphthalene and Tetradecane at 20oC Table 28: Aqueous concentration of components in Special Mixture at 5oC and 20oC 65 10 Summary The study of water solubility of contaminants has become important in the practice of contaminated site management, assessment and remediation. At the contaminated site it is not often found only one contaminant, many other substances can mix each other to form a contaminant mixture. In fact, in one field site we have a product phase which contaminated the soil. This phase consist of mineral oil, BTEX-compounds, PAH-compounds and phenol. If we use the solubility of these substances in literature, we would expect the water solubility for benzene with values of 1.7 g/l, for example. But on the site we only find benzene concentrations of 50 mg/l. That’s the reason to investigate which affect the water solubility of each component in the mixture. This work presents briefly theory of solubility, researches relating to water solubility of single compound and mixture, how to calculate water solubility of components in a mixture. This work determined the water solubility of six substances including Ethylbenzene, Toluene, Anthracene, Naphthalene, Phenol and Tetradacane at temperatures 5-10-20oC. Water solubility of mixtures of these substances was observed at temperatures 5 and 20oC. Solubility of single compounds compared to those in literature for determining accurate and precise received data. Water solubility of single compounds and mixture also compared them each other. The difference between these data was explained following solubility’s theory. Water solubility of some mixtures was calculated and compared to experimental value. Behaviours of components in the mixture also predict from experimental data. 11 1. INTRODUCTION Water solubility is one of the most important properties of compounds. Water solubility is defined as the concentration of a compound dissolved in water when that water is both in contact and at equilibrium with the pure chemical. Solubility represents an equilibrium distribution of a solute between water and the solute phase [1]. It is found various range of water solubility from hundred grams to only few ppb for organic substances. Some compounds are completely soluble in water such as methanol. Figure 1 shows range in water solubility of some organic compound classes in mol/liter. Figure 1: Ranges in water solubility of some organic compound classes [2] 12 Water solubility of almost substances was studied and listed in handbooks. However, in some cases, solubility of organic compounds in the pure form has not been determined, in references it is mentioned as “not soluble”, “insoluble”, “miscible”, “slightly soluble” or “moderate soluble”. Water solubility of some substances studied in this work is given as an example of this fact, and is shown on Table 1. Thus, water solubility is very important factor for controlling manufacture process, a valuable data in pharmaceutical study field and for controlling fate and transport of contaminants. If a highly soluble substance is quickly distributed, and diluted, an insoluble substance is more likely to adsorb on solids, or accumulate in biota. So, water solubility indicates the tendency of a chemical to be removed from soil to reach the surface water or ground water, to precipitate at the surface soil [2]. Present techniques for assessing or modelling the contaminant transport to environmental components typically rely on data such as solubility and the octanol-water partition coefficient for the calculation of bioconcentration factors, sediment adsorption coefficients, toxicity, and biodegradation rates. Simple example, if the amount of seepage water is known, the substance mass in the soil and their water solubility, mass of the contaminating substance which will be transported over the time to the groundwater can be calculated. And the lifetime of this soil contamination can also estimated. 13 Table 1: Chemical/physical properties of selected substances in this work Ethylbenzene(1) Toluene (1) Phenol (1) Anthracene (1) Naphthalene (1) Tetradecane (2) C8H10 / C6H5C2H5 106.2 C6H5CH3 / C7H8 92. C6H6O / C6H5OH 94.1 C14H10 / (C6H4CH)2 178.2 C10H8 C14H30 128.18 198.4 Boiling point 136°C 111°C 182°C 342°C 218°C Melting point -95°C -95°C 43°C 218°C 80°C 0.9 0.87 1.06 1.25-1.28 1.16 g/cm³ 0.763 0.015 (g/100 ml at 20°C) 0.9 (kPa) None (at 20°C) Moderate (at 20°C) None (at 25oC) insoluble 3.8 (kPa) 47 (Pa) 0.00013 (g/100 ml at 20oC) 0.08 (Pa) 3.2 2.69 1.46 4.5 3.3 Substance Formular Molecular mass Relative density (water = 1) Solubility in water Vapour pressure, at 20°C Octanol/water partition coefficient as log Pow 11 (Pa) (1) Data is cited from Physical Properties of International Chemical Safety Card of Ethylbenzene, Toluene, Phenol, Anthracene and Naphthalene [3] (2) Data is cited from Material Safety Data Sheet of N-Tetradecane [4] In fact, a substance is rarely found in the pure form in the nature, it is usually mixed with other substances and modified different from its origin. Especially, contaminated sites where substances have been become intermixed through careless dumping procedures or through failure to segregate waste steam [5]. In general, behavior of mixture of these substances is very complicated. If the mixture comes in contact with aqueous phase and form a solution, water solubility value of the single compounds from this mixture will not be the same like the value which listed in literature. Because these values are typically validate only for the solution of a single substance in pure water under laboratory conditions. Water solubility in both synthetic and environmental mixtures has been carrying out by scientists over the world. Relating to the selected compounds for this study, some 13 researches have been found and used in this as a literature source. Sujit Banerjee spent many years for researching on water solubility of components in liquid-liquid mixture, liquid-solid mixture and solid- solid mixture. Many his works have been publicized. He investigated solubility of many organic compounds and organic mixtures as well [6]. For example, solubility at 25oC of several chlorobenzenes, some mixtures of chlorobenzene, mixture of benzyl alcohol with several chlorobenzenes, mixture benzyl alcohol and toluene, ethyl acetate were determined. This work found that mixture of hydrophobic liquid is near ideal in the organic phase, in the aqueous phase the activity coefficient of a component was unaffected by the presence of cosolute. Increasing hydrophobicity of the solutes led to deviations from ideality in the organic phase. For the mixtures of solids which did not interact, the components tended to be behave independently of one other, and their solubility ware approximately additive. Clayton McAuliffe [7] determined the solubility in water at room temperature of 65 hydrocarbons including Paraffin and Branched-Chain Paraffin Hydrocarbons, Olefin Hydrocarbons, Acetylene Hydrocarbons, Cycloparaffin, Cycloolefin, and Aromatic Hydrocarbons by using a gas-liquid partition chromatographic technique. This work found branching increases water solubility for paraffin, olefin, and acetylene hydrocarbons, but not for cycloparaffin, cycloolefin, and aromatic hydrocarbons. For a given carbon number, ring formation increases water solubility. Double bond addition to the molecule, ring or chain, increases water solubility. The addition of a second and third double bond to a hydrocarbon of given carbon number proportionately increases water solubility. A triple bond in a chain molecule increases water solubility to a greater extent than two double bonds. Coyle, Harmon and Suffet [8] measured solubility of hydrophobic organic chemicals (HOC), including Naphthalene, Biphenyl, PCB-47, PCB-153, in water saturated with partially miscible organic solvents (PMOS), including methylene chloride and chloroform. Generator Column Technique was used for solubility measurement in mixed solution. The author concluded that solubility of Naphthalene was not much impacted by the solvents, while that’s of Biphenyl decreased slightly with increasing solvent’s 14 concentration. In aqueous phase, chloride and chloroform, PCB-47 concentration in aqueous phase were reduced about 25% and 15%, respectively, of its aqueous solubility. The solubility depression increased with increasing chemical hydrophobic of both HOC and solvents. Through the research results, the authors also explain behaviors of organic mixture and contaminant transport in soil and groundwater. The association of the solvents like methylene chloride and choroform with HOC phase will retard the transportations of this relatively mobile solute through sediments contaminated with HOC. And the presence of nearly saturated solution of PMOS will reduce the apparent solubility and therefore the mobility of the HOC. Aqueous solubility of PAH was determined by Donald Mackay and Wan Ying Shiu (1977). The solubility of 32 PAHs has been measured in water at 25oC. The results of ten of the compounds compare satisfactorily with literature values. Aqueous solubility can then be calculated directly for hydrocarbons which are liquid at 25oC [9]. Ghanima K. Al-Sharrah, Sami H. Ali and Mohamed A. Fahim (2001) measured solubility of anthracene in two mixed solvents toluene and 2-propanol and toluene and heptane is studied in the temperature range 20– 50oC. The comparison between experimental and predicted solubility by two models - UNIQUAC and modified UNIFAC is quite reasonable with an average prediction coefficient between 0.995 and 0.971 [10]. Other work of this group author (2005) investigated solubility of pyrene and phenanthrene in toluene solvent mixture of iso-octane and heptane over a temperature range from 2050oC. The experimental solubility data were used to predict the interaction parameters for seven different solid–liquid equilibrium models [11]. The solubility of several n-paraffins (from Dodecane C12 to Hexadecane C26) in both distilled water and seawater has been determined by Chris Sutton and John A. Calder (1974). The results shown these n-paraffins have very low water solubility in ppb range. But n-paraffin is less soluble in seawater than in distilled water. This work also indicates importance of salting out effect on water solubility. This fact explains transportation and fate of paraffins in seawater and estuaries area [12]. 15 The solubility of normal paraffins from methane to decane (C10) has been investigated by Mc.Auliffe (1969). This work found that the solubility at 25oC of the normal alkanes decrease with increasing carbon number (solubility of C9 is 220 ppb and C10 is 52 ppb) [13]. An important database on solubility - IUPAC Solubility Data Series, containing solubility originally published in International Union for Pure and Applied Chemistry is now available online. There are over 67,500 solubility measurements. There are about 1800 chemical substances in the database and 5200 systems, of which 473 have been critically evaluated. Solubility and liquid-liquid equilibrium of binary, ternary and quaternary systems are presented. Typical solvents and solutes include water, sea water, heavy water, inorganic compounds, and a variety of organic compounds such as hydrocarbons, halogenated hydrocarbons, alcohols, acids, esters and nitrogen compounds. For many systems, sufficient data were available to allow critical evaluation. Data are expressed as mass and mole fractions as well as the originally reported units [14]. 16 1.1 Some important definition related to solubility Solubility is referred as the ability for a given substance, call the solute (solute can be a solid, liquid or gas), to dissolve in a solvent. It is measured in terms of the maximum amount of solute dissolved in a solvent at equilibrium [3]. A solution is a liquid or solid phase containing more than one substance, when for convenience one of the substances, which is called the solvent, and may itself be a mixture, is treated differently than the other substances, which are called solutes. If the sum of the mole fractions of the solutes is small compared to unity, the solution is called a dilute solution [3]. A mixture is describes a gaseous, liquid or solid phase containing more than one substance, where the substances are all treated in the same way [3]. Activity coefficient (γ) of a substance is defined as the chemical potential of its in liquid or solid mixture. An activity coefficient is a factor used in thermodynamics to account for deviations from ideal behavior in a mixture of chemical substances [15]. For pure compound dilute in water, activity coefficient of this solute in the solute phase is unity. But in mixture many components interact within the mixture, had led to changes of mixture’s solubility. In general, interaction takes place between solute in the organic phase, rather than in the aqueous phase. Hydrophobic solutes tend to be diluted in the aqueous phase to interact significantly each other. Liquid solute are usually mix each other resulting to they are able to interact within the organic phase. Solid solutes tend not to mix with other ones and they behave independently each other. In this case, mixture’s solubility of solids is frequently the sum of the solubility of its components [1]. It is said that water solubility represents equilibrium of a solute between water and solute phase. The following will discuss more details about type of solute and solute phase, the way of solute and solute effects on solubility. 17 There are three type of solute including liquid solute, gaseous solute and solid solute. For liquid solutes, the ideal solution tends to be formed if the solute and solvent molecules are very similar in size and in the nature of their intermolecular interactions. Solutions of n-heptane in hexane, toluene in benzene or carbon tetrabromide in carbon tetracholoride are very nearly ideal. Other case, the solute and solvent molecules are similar polarity but have great difference of molecule size, the solution of them is considered as an ideal mixture. For solid solute, it is necessary to account for the inhibitory effect of crystal structure upon solubility. It is well known that the solubility of a crystalline solute in any solvent depends on properties of the crystals which is given by the van’ Hoff equation. Gaseous behavior is explained by Henry’s Law which says the solubility of a gas in a liquid is proportional to the pressure of the gas. 1.2 FACTORS INFLUENCING SOLUBILITY 1.2.1 Temperature effects: Aqueous solubility is a function of temperature. Increasing temperature reduces waterwater, water – solute and solute – solute interactions [1]. Figure 2 shows temperature effects on solubility of some compounds. For solid solutes, the effect of temperature is important. The solubility generally increases with temperature, in the temperature range from about room temperature to 100°C. About 95% solid solute obeys this rule of thumb. However, some of solid only have solubility increase in a certain range of temperature [1]. The detail of this fact will be discussed later. For most gaseous solutes, the water solubility decreases with increasing temperature. That means as the temperature is raised gases usually become less soluble in 18 water. Many organic liquids exhibit minima in solubility at room temperature. In general, solubility of solids is much more sensitive to temperature effect than liquids [1] Figure 2: Water solubility as a function of temperature. [2] Temperature effects on solubility can be different, depending on the temperature range. Evidence of this fact is shown in Table 2. Solubility of some organic compounds only slightly depends on temperature in certain range. Some of compounds have complex behaviors, for example Benzene solubility decreases with increasing temperature below ~15°C, but increases with increasing temperature above ~20°C [2]. 19 Table 2: Difference of solubility in different temperature [1] Solute Relative Solubility mdichlorobenzene Diethyl phthalate 10oC 20oC 1.00 0.77 1.20 1.00 0.84 0.87 1.00 0.97 1,1,2,2tetrachloroethane Octachlorobiphenyl Phenanthrene 1.00 Fluorene 4-nitrophenol 1.00 25oC 30oC 40oC 50oC 0.99 1.29 6.72 1.00 1.29 2.09 3.51 1.00 1.27 2.02 3.31 1.62 2.29 1.2.2 Pressure effects For solid and liquid phase, the influence of pressure on solubility is typically weak and usually neglected in practice. The effect of pressure on solubility is only important at very high pressure. Table 3: Effect of pressure on the solubility of Xylene [1] Pressure (MPa) Percent increase in solubility o-xylene m-xylene p-xylene 0.1 1 1 1 50 7.7 7.3 8.6 100 13.2 10.5 8 150 12.5 10.4 200 10.2 8.1 250 5.6 5.8 300 2.4 350 -1.9 385 -5.4
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