Chemical fate and transport in the environment.

1. Hazardous Waste Management Kitipan Kitbamroong Ph.D. 7 January, 2011

2. Description Chemical fate and transport in the environment. Frequency and magnitude of accidents involving hazardous materials. Effects of these releases on the community

3. Textbooks Hemond, H.F. and E.J. Fechner-Levy. Chemical Fate and Transport in the Environment. 2nd edition. Academic Press. ISBN: 0123402751. 448 pages. October 1999.

4. Instructor and Goals Instructor: Kitipan Kitbamroong Ph.D., email kitipan@gmail.com Course Goals: Integrate chemical property information to better understand the transport and fate of hazardous chemicals released to the environment. Examine case studies to understand the long-term social and environmental effects of these releases.

5. Topics and Agenda 1.1 Introduction 1.2 Chemical Concentration 1.3 Mass Balance and Units 1.4 Physical Transport of Chemicals 1.5 Mass Balance in an Infinitely Small Control Volume 1.6 Basic Environmental Chemistry 1.7 Error in Measurements of Environmental Quantities 1.8 Chemical Distribution among phases

6. 1.1 Introduction “By sensible definition any by-product of a chemical operation for which there is no profitable use is a waste. The most convenient, least expensive way of disposing of said waste – up the chimney or down the river – is the best.” Haynes, W. American Chemical Industry, A History. Van Nostrand, NY. 1954.

9. Processes 1.) wick effect:when water evaporates from soil surface, the suction gradient produced results in an appreciable upward movement of water to replace that evaporated 2.) infiltration: (atmosphere soil) precipitation that doesn’t simply runoff the land surface into a surface water body or storm drains enters the unsaturated zone (soil) 3.) evapotranspiration:evaporation from leaves (water from plant root uptake through the lip of leave) 4.) dry deposition: any physical removal process that doesn’t involve precipitation, there are three main mechanisms : gravitational settling (particle in the streamline settle down), impaction (happen when hit building or something), absorption (particle absorpto surface of object) 5.) rainout:mechanism in wet deposition (removal process that involve precipitation), involve s incorporation of chemical into water droplet that occur *within a cloud

10. Processes 6.) washout: wet deposition, occurs *beneath a cloud as precipitation fall through the air toward the earth surface 7.) evaporation: process in which liquid transform to vapor, moving to atmosphere 8.) bubble bursting (sea spray): occur in few mm above ocean surface, there is a lot of small water bubble (1-100 m dia) generate from dynamic action and come up from ocean surface & broken in that top layer 9.) codistillation:evaporation & volatilization at the same time (simultaneous) 10.) excretion : the release of compound from organism to soil and water

11. Processes 11.) ingestion: uptake from soil and water to organism 12.) infiltration: (water-soil), movement of water from surface water body to unsaturated zone, soil act as filter 13.) percolation: movement of water from unsaturated zone to sat (groundwater) 14.) runoff: precipitation that runoff the land surface into a surface water body 15.) leaching: dissolution of soluble compound from soil to water

12. 1.2 Chemical Concentrations Mass per unit volume [M/L3], such as mg/L, is the most common expression for water. ppm and ppb are often used. Mg/kg is often used for soils because the mass of soil does not vary.

13. 1.3 Mass Balances and Units Three possible outcomes exist for a chemical present at a specific location in the environment at a particular time: The chemical can remain in that location Can be carried elsewhere by a transport process Eliminated through transformation into another chemical. The RULES of mass balance or mass conservation

14. 1.3 Mass Balances and Units Mass Balance Equation Change in storage of mass = mass transported in – mass transported out + mass produced by sources – mass eliminated by sinks Mass Balance Rate Equation (mass per time) Rate of change in storage of mass = mass transported rate in – mass transport rate out + mass production rate by sources – mass elimination rate by sinks

15. 1.4 Physical Transport of Chemicals Advection Transport Fickian Transport

16. 1.5 Advection-Dispersion-Reaction Equation

17. 1.6 Basic Environmental Chemistry 1.6.1 Chemical Kinetics 1.6.2 Gibbs Free Energy

18. 1.6 Basic Environmental Chemistry 1.6.3 Chemical Equilibrium 1.6.4 Electroneutrality 1.6.5 Activity

19. 1.6 Basic Environmental Chemistry 1.6.6 Chemical Kinetics First Order Kinetics – leads to exponential decay or first-order decay Half Life - the amount of time it takes for the parent compound to decay to half its initial concentration

20. 1.7 Error in Measurements of Environmental Quantities The error of observation is the difference between the measured value of a quantity and the accurate value.

21. 1.8 Multiple phases present in the environment 1.8.1 Solubility and Vapor Pressure Aqueous solubility is the concentration of a chemical dissolved in water when that water is both in contact and at equilibrium with the pure chemical. 1.8.2 Henry’s Law Constants A partition coefficient describes how a chemical distributes itself between two different phases. The Henry’s Law constant, H (or KH), is a partition coefficient defined as the ratio of a chemical’s concentration in air to its concentration in water at equilibrium 1.8.3 Chemical Partitioning to Solids

22. 1.8 Multiple phases present in the environment 1.8.3 Chemical Partitioning to Solids Sorption is the term used to describe the chemical partitioning between air and solid phases. Adsorption is when the chemical sticks to the two-dimensional surface of a solid. Absorption is when the chemical diffuses into a three-dimensional solid.

23. 1.8 Multiple phases present in the environment 1.8.3 Fugacity Fugacity literally means the “tendency to flee” and is used to determine to the relative concentrations of a chemical in air, water, and soil phases at equilibrium (can also be used to include other environmental phases, such as fish, bottom sediments, dissolved gases, suspended sediment) Fugacity has units of pressure and is related to concentrations through a fugacity capacity constant (in units of mol/atm-m3)

24. 1.8.3 Fugacity Level I Level II Level III and IV