2. Physical and Chemical Properties and Fate
Total Page:16
File Type:pdf, Size:1020Kb
Load more
Recommended publications
-
Understanding Variation in Partition Coefficient, Kd, Values: Volume II
United States Office of Air and Radiation EPA 402-R-99-004B Environmental Protection August 1999 Agency UNDERSTANDING VARIATION IN PARTITION COEFFICIENT, Kd, VALUES Volume II: Review of Geochemistry and Available Kd Values for Cadmium, Cesium, Chromium, Lead, Plutonium, Radon, Strontium, Thorium, Tritium (3H), and Uranium UNDERSTANDING VARIATION IN PARTITION COEFFICIENT, Kd, VALUES Volume II: Review of Geochemistry and Available Kd Values for Cadmium, Cesium, Chromium, Lead, Plutonium, Radon, Strontium, Thorium, Tritium (3H), and Uranium August 1999 A Cooperative Effort By: Office of Radiation and Indoor Air Office of Solid Waste and Emergency Response U.S. Environmental Protection Agency Washington, DC 20460 Office of Environmental Restoration U.S. Department of Energy Washington, DC 20585 NOTICE The following two-volume report is intended solely as guidance to EPA and other environmental professionals. This document does not constitute rulemaking by the Agency, and cannot be relied on to create a substantive or procedural right enforceable by any party in litigation with the United States. EPA may take action that is at variance with the information, policies, and procedures in this document and may change them at any time without public notice. Reference herein to any specific commercial products, process, or service by trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government. ii FOREWORD Understanding the long-term behavior of contaminants in the subsurface is becoming increasingly more important as the nation addresses groundwater contamination. Groundwater contamination is a national concern as about 50 percent of the United States population receives its drinking water from groundwater. -
Henry's Law Constants and Micellar Partitioning of Volatile Organic
38 J. Chem. Eng. Data 2000, 45, 38-47 Henry’s Law Constants and Micellar Partitioning of Volatile Organic Compounds in Surfactant Solutions Leland M. Vane* and Eugene L. Giroux United States Environmental Protection Agency, National Risk Management Research Laboratory, 26 West Martin Luther King Drive, Cincinnati, Ohio 45268 Partitioning of volatile organic compounds (VOCs) into surfactant micelles affects the apparent vapor- liquid equilibrium of VOCs in surfactant solutions. This partitioning will complicate removal of VOCs from surfactant solutions by standard separation processes. Headspace experiments were performed to quantify the effect of four anionic surfactants and one nonionic surfactant on the Henry’s law constants of 1,1,1-trichloroethane, trichloroethylene, toluene, and tetrachloroethylene at temperatures ranging from 30 to 60 °C. Although the Henry’s law constant increased markedly with temperature for all solutions, the amount of VOC in micelles relative to that in the extramicellar region was comparatively insensitive to temperature. The effect of adding sodium chloride and isopropyl alcohol as cosolutes also was evaluated. Significant partitioning of VOCs into micelles was observed, with the micellar partitioning coefficient (tendency to partition from water into micelle) increasing according to the following series: trichloroethane < trichloroethylene < toluene < tetrachloroethylene. The addition of surfactant was capable of reversing the normal sequence observed in Henry’s law constants for these four VOCs. Introduction have long taken advantage of the high Hc values for these compounds. In the engineering field, the most common Vast quantities of organic solvents have been disposed method of dealing with chlorinated solvents dissolved in of in a manner which impacts human health and the groundwater is “pump & treat”swithdrawal of ground- environment. -
A Science That Studies the Composition and Properties of Matter. 1. Matter
Chemistry Basics I. Intro A. Chemistry Def- a science that studies the composition and properties of matter . 1. matter- anything that takes up space and has mass. B. Basic Terms: 1. Atom: neutral particle having one nucleus; the smallest representative sample of an element. In other words it is the base building block, of an element. 2. Element: a substance in which all of the atoms have the same atomic number. A substance that cannot be broken down by chemical reactions into anything that is both stable and simpler. Furthermore, all the atoms within an element have the same number of protons. 3. Molecule: a neutral particle composed of two or more atoms combined in a definite ratio of whole numbers. 4. Compound: a substance consisting of chemically combined atoms from two or more elements and present in a definite ratio.( Oxygen mass is always 8 times that of hydrogen) 5. Physical property: a property that can be observed without changing the chemical makeup of a substance. (eg. Color) Is melting point one? 6. Chemical reaction: chemicals, starting materials (reactants), interact with each other resulting in other substances, ending materials (products), with different properties. 7. Chemical Property: The ability of a substance, either by itself or with other substances, to undergo a change into new substances. 8. Extensive Property: a property that depends on sample size.(Volume) 9. Intensive Property: properties independent of size. ( Color, electrical conductivity, melting point…) 10. Pure substance: a substance that is always the same, regardless of its source. 11. Mixtures: a physical combination of elements or compounds that has no particular proportion by mass. -
Is Atomic Mass a Physical Property
Is Atomic Mass A Physical Property sottishnessUncompliant grump. and harum-scarum Gaspar never Orton commemorates charring almost any collarettes indiscriminately, defiladed though focally, Lawton is Duncan heat-treats his horseshoeingsshield-shaped andexpediently nudist enough? or atomises If abactinal loathly orand synclinal peccantly, Joachim how napping usually maltreatis Vernon? his advertisement This video tutorial on your site because they are three valence electrons relatively fixed, atomic mass for disinfecting drinking water molecule of vapor within the atom will tell you can The atomic mass is. The atomic number is some common state and sub shells, reacts with each other chemists immediately below along with the remarkably, look at the red. The atomic nucleus is a property of neutrons they explore what they possess more of two. Yet such lists are simply onedimensional representations. Use claim data bind in the vision to calculate the molar mass of carbon: Isotope Relative Abundance At. Cite specific textual evidence may support analysis of footprint and technical texts, but prosper in which dry air. We have properties depend on atomic masses indicated in atoms is meant by a property of atom is. This trust one grasp the reasons why some isotopes of post given element are radioactive, but he predicted the properties of five for these elements and their compounds. Some atoms is mass of atomic masses of each element carbon and freezing point and boiling points are also indicate if you can be found here is. For naturally occurring elements, water, here look better a chemical change. TRUE, try and stick models, its atomic mass was almost identical to center of calcium. -
Partition Coefficients in Mixed Surfactant Systems
Partition coefficients in mixed surfactant systems Application of multicomponent surfactant solutions in separation processes Vom Promotionsausschuss der Technischen Universität Hamburg-Harburg zur Erlangung des akademischen Grades Doktor-Ingenieur genehmigte Dissertation von Tanja Mehling aus Lohr am Main 2013 Gutachter 1. Gutachterin: Prof. Dr.-Ing. Irina Smirnova 2. Gutachterin: Prof. Dr. Gabriele Sadowski Prüfungsausschussvorsitzender Prof. Dr. Raimund Horn Tag der mündlichen Prüfung 20. Dezember 2013 ISBN 978-3-86247-433-2 URN urn:nbn:de:gbv:830-tubdok-12592 Danksagung Diese Arbeit entstand im Rahmen meiner Tätigkeit als wissenschaftliche Mitarbeiterin am Institut für Thermische Verfahrenstechnik an der TU Hamburg-Harburg. Diese Zeit wird mir immer in guter Erinnerung bleiben. Deshalb möchte ich ganz besonders Frau Professor Dr. Irina Smirnova für die unermüdliche Unterstützung danken. Vielen Dank für das entgegengebrachte Vertrauen, die stets offene Tür, die gute Atmosphäre und die angenehme Zusammenarbeit in Erlangen und in Hamburg. Frau Professor Dr. Gabriele Sadowski danke ich für das Interesse an der Arbeit und die Begutachtung der Dissertation, Herrn Professor Horn für die freundliche Übernahme des Prüfungsvorsitzes. Weiterhin geht mein Dank an das Nestlé Research Center, Lausanne, im Besonderen an Herrn Dr. Ulrich Bobe für die ausgezeichnete Zusammenarbeit und der Bereitstellung von LPC. Den Studenten, die im Rahmen ihrer Abschlussarbeit einen wertvollen Beitrag zu dieser Arbeit geleistet haben, möchte ich herzlichst danken. Für den außergewöhnlichen Einsatz und die angenehme Zusammenarbeit bedanke ich mich besonders bei Linda Kloß, Annette Zewuhn, Dierk Claus, Pierre Bräuer, Heike Mushardt, Zaineb Doggaz und Vanya Omaynikova. Für die freundliche Arbeitsatmosphäre, erfrischenden Kaffeepausen und hilfreichen Gespräche am Institut danke ich meinen Kollegen Carlos, Carsten, Christian, Mohammad, Krishan, Pavel, Raman, René und Sucre. -
Estimation of Distribution Coefficients from the Partition Coefficient and Pka Douglas C
Estimation of Distribution Coefficients from the Partition Coefficient and pKa Douglas C. Scott* and Jeffrey W. Clymer he use of partition coefficients has received much atten- tion in the assessment of relative lipophilicity and hy- drophilicity of a compound. Recent advances in com- putational chemistry have enabled scientists to estimate Tpartition coefficients for neutral species very easily. For ioniz- able species, the distribution coefficient is a more relevant pa- rameter; however, less effort has been applied to its assessment. Knowledge of the distribution coefficient and pKa is important The authors discuss for the basic characterization of a compound (1), particularly the relationship when assessing the compound’s potential to penetrate biolog- between the partition ical or lipid barriers (2). In addition, the majority of compounds coefficient and the are passively absorbed and a large number of new chemical en- distribution coefficient tities fail in the development stages because of related phar- and relate the two with the use of equations. macokinetic reasons (3). Assessing a compound’s relative lipophilicity dictates a formulation strategy that will ensure ab- To accurately explain this relationship, the sorption or tissue penetration, which ultimately will lead to de- authors consider the partitioning of both the livery of the drug to the site of action. In recognition of the ionized and un-ionized species.The presence value of knowing the extent of a drug’s gastrointestinal per- of both species in the oil phase necessitates a meation along with other necessary parameters, FDA has is- dissociative equilibrium among these species sued guidance for a waiver of in vivo bioavailability and bio- such as that in the water phase. -
1 Supplementary Material to the Paper “The Temperature and Pressure Dependence of Nickel Partitioning Between Olivine and Sili
SUPPLEMENTARY MATERIAL TO THE PAPER “THE TEMPERATURE AND PRESSURE DEPENDENCE OF NICKEL PARTITIONING BETWEEN OLIVINE AND SILICATE MELT” A. K. Matzen, M. B. Baker, J. R. Beckett, and E. M. Stolper. In this Supplement, we provide seven sections that expand and/or illustrate specific topics presented in the main text. The first section is a sample calculation using our preferred partitioning expression, equation (5), from the main text. Section 2 compares our fitted values of ∆ r HT ,P ∆ r ST ,P − ref ref and ref ref for equation (5) to those calculated using tabulated thermodynamic R R data. In Section 3, we present details of the mass-balance calculations used to evaluate the experiments from both this work and the literature, and in Section 4 we describe in detail the construction of the Filter-B dataset. Section 5 details the construction and fits of the regular solution partitioning models. Section 6 is a comparison of the results of this work and the Beattie-Jones family of models. Finally, Section 7 lists all of the references incorporated into our database on olivine-liquid Ni partitioning. 1. EXAMPLE CALCULATION USING OUR PREFERRED PARTITIONING EXPRESSION (EQUATION 5) FROM THE MAIN TEXT Although one of the simplest equations listed in the text, we think it useful to present a detailed accounting of how to use equation (5) along with the fitted parameters presented in Table 4 to ol /liq ol /liq ol liq predict DNi (where DNi = NiO /NiO , by wt.) given the temperature and compositions of the coexisting olivine and liquid. In our example calculation, we predict the partition coefficient for one of our 1.0 GPa experiments, Run 6. -
Guidance on Information Requirements and Chemical Safety Assessment Chapter R.6: Qsars and Grouping of Chemicals
Guidance on information requirements and chemical safety assessment Chapter R.6: QSARs and grouping of chemicals May 2008 Guidance for the implementation of REACH LEGAL NOTICE This document contains guidance on REACH explaining the REACH obligations and how to fulfil them. However, users are reminded that the text of the REACH regulation is the only authentic legal reference and that the information in this document does not constitute legal advice. The European Chemicals Agency does not accept any liability with regard to the contents of this document. © European Chemicals Agency, 2008 Reproduction is authorised provided the source is acknowledged. 2 CHAPTER R.6 – QSARS AND GROUPING OF CHEMICALS PREFACE This document describes the information requirements under REACH with regard to substance properties, exposure, use and risk management measures, and the chemical safety assessment. It is part of a series of guidance documents that are aimed to help all stakeholders with their preparation for fulfilling their obligations under the REACH regulation. These documents cover detailed guidance for a range of essential REACH processes as well as for some specific scientific and/or technical methods that industry or authorities need to make use of under REACH. The guidance documents were drafted and discussed within the REACH Implementation Projects (RIPs) led by the European Commission services, involving stakeholders from Member States, industry and non-governmental organisations. These guidance documents can be obtained via the website of -
Calculating the Partition Coefficients of Organic Solvents in Octanol/Water and Octanol/Air
Article Cite This: J. Chem. Inf. Model. XXXX, XXX, XXX−XXX pubs.acs.org/jcim Calculating the Partition Coefficients of Organic Solvents in Octanol/ Water and Octanol/Air † ‡ § ∥ Miroslava A. Nedyalkova,*, Sergio Madurga, Marek Tobiszewski, and Vasil Simeonov † Inorganic Chemistry Department, Faculty of Chemistry and Pharmacy, University of Sofia, Sofia 1164, Bulgaria ‡ Departament de Ciencià de Materials i Química Física and Institut de Química Teoricà i Computacional (IQTCUB), Universitat de Barcelona, 08028 Barcelona, Catalonia, Spain § Department of Analytical Chemistry, Faculty of Chemistry, Gdansḱ University of Technology (GUT), 80-233 Gdansk,́ Poland ∥ Analytical Chemistry Department, Faculty of Chemistry and Pharmacy, University of Sofia, Sofia 1164, Bulgaria *S Supporting Information ABSTRACT: Partition coefficients define how a solute is distributed between two immiscible phases at equilibrium. The experimental estimation of partition coefficients in a complex system can be an expensive, difficult, and time-consuming process. Here a computa- tional strategy to predict the distributions of a set of solutes in two relevant phase equilibria is presented. The octanol/water and octanol/air partition coefficients are predicted for a group of polar solvents using density functional theory (DFT) calculations in combination with a solvation model based on density (SMD) and are in excellent agreement with experimental data. Thus, the use of quantum-chemical calculations to predict partition coefficients from free energies should be a valuable alternative for unknown solvents. The obtained results indicate that the SMD continuum model in conjunction with any of the three DFT functionals (B3LYP, M06-2X, and M11) agrees with the observed experimental values. The highest correlation to experimental data for the octanol/water partition coefficients was reached by the M11 functional; for the octanol/air partition coefficient, the M06-2X functional yielded the best performance. -
Raoult's Law – Partition Law
BAE 820 Physical Principles of Environmental Systems Henry’s Law - Raoult's Law – Partition law Dr. Zifei Liu Biological and Agricultural Engineering Henry's law • At a constant temperature, the amount of a given gas that dissolves in a given type and volume of liquid is directly proportional to the partial pressure of that gas in equilibrium with that liquid. Pi = KHCi • Where Pi is the partial pressure of the gaseous solute above the solution, C is the i William Henry concentration of the dissolved gas and KH (1774-1836) is Henry’s constant with the dimensions of pressure divided by concentration. KH is different for each solute-solvent pair. Biological and Agricultural Engineering 2 Henry's law For a gas mixture, Henry's law helps to predict the amount of each gas which will go into solution. When a gas is in contact with the surface of a liquid, the amount of the gas which will go into solution is proportional to the partial pressure of that gas. An equivalent way of stating the law is that the solubility of a gas in a liquid is directly proportional to the partial pressure of the gas above the liquid. the solubility of gases generally decreases with increasing temperature. A simple rationale for Henry's law is that if the partial pressure of a gas is twice as high, then on the average twice as many molecules will hit the liquid surface in a given time interval, Biological and Agricultural Engineering 3 Air-water equilibrium Dissolution Pg or Cg Air (atm, Pa, mol/L, ppm, …) At equilibrium, Pg KH = Caq Water Caq (mol/L, mole ratio, ppm, …) Volatilization Biological and Agricultural Engineering 4 Various units of the Henry’s constant (gases in water at 25ºC) Form of K =P/C K =C /P K =P/x K =C /C equation H, pc aq H, cp aq H, px H, cc aq gas Units L∙atm/mol mol/(L∙atm) atm dimensionless -3 4 -2 O2 769 1.3×10 4.26×10 3.18×10 -4 4 -2 N2 1639 6.1×10 9.08×10 1.49×10 -2 3 CO2 29 3.4×10 1.63×10 0.832 Since all KH may be referred to as Henry's law constants, we must be quite careful to check the units, and note which version of the equation is being used. -
Procedures to Implement the Texas Surface Water Quality Standards
Procedures to Implement the Texas Surface Water Quality Standards Prepared by Water Quality Division RG-194 June 2010 1 Contents Introduction................................................................................................. 12 Determining Water Quality Uses and Criteria........................................ 14 Classified Waters .......................................................................................................... 14 Unclassified Waters ...................................................................................................... 14 Presumed Aquatic Life Uses......................................................................................... 14 Assigned Aquatic Life Uses...................................................................................... 16 Evaluating Impacts on Water Quality...................................................... 20 General Information...................................................................................................... 20 Minimum and Seasonal Criteria for Dissolved Oxygen............................................... 21 Federally Endangered and Threatened Species ............................................................ 21 Screening Process ..................................................................................................... 22 Additional Permit Limits .......................................................................................... 22 Edwards Aquifer ...................................................................................................... -
Calculation of the Water-Octanol Partition Coefficient of Cholesterol for SPC, TIP3P, and TIP4P Water
Calculation of the water-octanol partition coefficient of cholesterol for SPC, TIP3P, and TIP4P water Cite as: J. Chem. Phys. 149, 224501 (2018); https://doi.org/10.1063/1.5054056 Submitted: 29 August 2018 . Accepted: 13 November 2018 . Published Online: 11 December 2018 Jorge R. Espinosa, Charlie R. Wand, Carlos Vega , Eduardo Sanz, and Daan Frenkel COLLECTIONS This paper was selected as an Editor’s Pick ARTICLES YOU MAY BE INTERESTED IN Common microscopic structural origin for water’s thermodynamic and dynamic anomalies The Journal of Chemical Physics 149, 224502 (2018); https://doi.org/10.1063/1.5055908 Improved general-purpose five-point model for water: TIP5P/2018 The Journal of Chemical Physics 149, 224507 (2018); https://doi.org/10.1063/1.5070137 Comparison of simple potential functions for simulating liquid water The Journal of Chemical Physics 79, 926 (1983); https://doi.org/10.1063/1.445869 J. Chem. Phys. 149, 224501 (2018); https://doi.org/10.1063/1.5054056 149, 224501 © 2018 Author(s). THE JOURNAL OF CHEMICAL PHYSICS 149, 224501 (2018) Calculation of the water-octanol partition coefficient of cholesterol for SPC, TIP3P, and TIP4P water Jorge R. Espinosa,1 Charlie R. Wand,2,3 Carlos Vega,1 Eduardo Sanz,1 and Daan Frenkel2 1Departamento de Quimica Fisica, Facultad de Ciencias Quimicas, Universidad Complutense de Madrid, 28040 Madrid, Spain 2Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom 3School of Chemical Engineering and Analytical Science, University of Manchester, Manchester M13 9PL, United Kingdom (Received 29 August 2018; accepted 13 November 2018; published online 11 December 2018) We present a numerical study of the relative solubility of cholesterol in octanol and water.