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Chemical fate and transport in the environment. Frequency and magnitude of accidents involving hazardous materials. Effects of these releases on the community.
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Hazardous Waste Management
Kitipan Kitbamroong Ph.D.7 January, 2011
Description
• Chemical fate and transport in
the environment. Frequency
and magnitude of accidents
involving hazardous materials.
Effects of these releases on the
community
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.
Instructor and Goals
• Instructor: Kitipan Kitbamroong Ph.D., email
• 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.
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
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.
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 absorp to 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
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
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
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.
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:
o The chemical can remain in that location
o Can be carried elsewhere by a transport process
o Eliminated through transformation into another chemical.
o The RULES of mass balance or mass conservation
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
1.4 Physical Transport of Chemicals
• Advection Transport
• Fickian Transport
1.5 Advection-Dispersion-Reaction Equation
1.6 Basic Environmental Chemistry
• 1.6.1 Chemical Kinetics
• 1.6.2 Gibbs Free Energy
1.6 Basic Environmental Chemistry
• 1.6.3 Chemical Equilibrium
• 1.6.4 Electroneutrality
• 1.6.5 Activity
1.6 Basic Environmental Chemistry
• 1.6.6 Chemical Kineticso First Order Kinetics – leads to exponential decay or first-order
decay
o Half Life - the amount of time it takes for the parent compound
to decay to half its initial concentration
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.
1.8 Multiple phases present in the environment
• 1.8.1 Solubility and Vapor Pressureo 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 Constantso A partition coefficient describes how a chemical distributes itself
between two different phases.
o 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
1.8 Multiple phases present in the environment
• 1.8.3 Chemical Partitioning to Solidso Sorption is the term used to describe the chemical partitioning
between air and solid phases.
o Adsorption is when the chemical sticks to the two-dimensional
surface of a solid.
o Absorption is when the chemical diffuses into a three-
dimensional solid.
1.8 Multiple phases present in the environment
• 1.8.3 Fugacityo 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)
o Fugacity has units of pressure and is related to concentrations
through a fugacity capacity constant (in units of mol/atm-m3)
1.8.3 Fugacity
Level I
Level II
Level III and IV
