Upload
adrian-flynn
View
219
Download
1
Tags:
Embed Size (px)
Citation preview
Environmental Modeling
Chapter 1:Sources and Types of Pollutant
(why we need modeling, and historical contamination events)
Copyright © 2006 by DBS
Quote
“Through the history of literature, the guy who poisons the well has been the worst of all villains”
-Author unknown
Concepts
• Need for modeling• Pollutant classification• Sources• Historical examples
IntroductionSequence of Events
1. Observation of pollutant release (or potential for)– Monitoring, known manufacturing process, cancer cluster,
impact assessment
2. Source is identified or theoretical release simulated to find source
3. Modelling (fate and transport) spatially and temporally estimates exposure levels
4. Risk assessment calculations estimate health risks
5. Remediation plan developed between local citizens, local/federal government, party responsible
Text book
Need for Modeling
• Pollutants are ubiquitous – found in all environmental compartments
e.g. PCB’s and DDT – refractory (resistant to heat)
• Divide environment into mathematically described boxes
– Explain how a pollutant got where it is (thermodynamics)
– Predict how fast it will move through the compartment (kinetics)
Need for ModelingEnvironmental Compartments
Need for ModelingFate and Transport Equations
• Describe physical and chemical processes– Mixing, outflow, evaporation, volatilization, chemical or biological degradation
Predictive Explanation
Types of Modeling
Equations are fit to pollutant concentration data from field studies
Used to obtain mixing and degradation rates specific to system
Shows how concentrations will change with distance and time
Predicts outcome of pollution episode (exposure)
Pollution vs. Contamination
• Pollution and pollutant
– Preferred by environmentalists and EPA
• Contamination and contaminant
– Preferred by US DOE
• Legal defination specifies concentration and location
Pollutant ClassificationsVary Country to Country
• Physical phase – for treatment and disposal
Solid GasLiquid
Pollutant ClassificationsVary Country to Country
Inorganic OrganicRadioactive
Metals Metalloids Non-metals
Toxic Non-Toxic
TransitionMetals
HeavyMetals
Chemical type:
Make connections
Pollutant ClassificationsVary Country to Country
Inorganic OrganicRadioactive
Metals Metalloids Non-metals
Toxic Non-Toxic
TransitionMetals
HeavyMetals
Chemical type
Pollutant ClassificationsRisk
• e.g. hazardous waste site with 20 pollutants
• 5 out of 20 pose significantly higher health risk
• Remediation may be focussed on the 5 most dangerous
Assessing Risk (EPA, 1989)
Sources
• Point – well-defined source (e.g. end of a pipe, smokestack, drain)
• Non-point - less well defined, cannot be pinpointed
Arbitrary to some extent – depends on spatial scale
e.g. air - one smoke stack (P) meaningless to analysis of regional air pollution, 100’s of stacks become NP source
e.g. water - one house septic system (P), on a regional scale may be considered NP
Discharge from waste water plant contaminates ground and surface water
Source: USGS
Point and Non-point Sources
Smol, 2002
Sources
Source General Waste (representative)
Agricultural Field and chemical waste, nutrients, pesticides/herbicides, petroleum fuels, feedlot waste, dairy waste
Chemical Industry Metal products, metal sludges, nonmetal waste, electrical equipment waste, detergents/soaps/cleaners, petroleum, metal plating, film processing, solvents, wastewaters, pesticides, smog precursors (NOX, HC’s)
Mining Industry Mine tailings, Mineral leachate (CN), acid mine drainage, coal, smelting waste, particulates
Energy Industry Petroleum-based waste, solvents, gas and vapor emissions, coal tars, boiler waste, nuclear waste, petroleum stored underground, smog and acid rain precursors ((NOX, HC’s)
Landfills Chemicals
Incinerators Incomplete combustion of feedstock, combustion by-prodcuts, metals, particulates
Medical Industry Biohazards, pharmaceutical waste, solvents
Food Processing Waste food products, rinsing waste, slaughterhouse waste
Domestic Waste Detergents/cleaners, pesticides, fertilizers, compost, paints/solvents, gasoline
Municipal Governments Water and wastewater treatment chemicals, sewage
Federal Givernemnt Weapons-related waste, nuclear waste, petroleum-based waste
SourcesBasel Convention
• International treaty regulating reporting, disposal and transport of hazardous waste
• Designed to reduce movement of waste
• Nuclear waste not included!
http://www.basel.int/natreporting/index.html
Questions
1. Correlate hazardous waste to a country’s development level (economic status).
2. Calculate the import/export ratio (if ratio > 1 the country is a net importer). Are there any net importers?
3. Why are Germany and Japan absent from the list?
4. How does the US hazardous waste amount compare to the rest of the world?
5. Why is the US (40,821,482 tons in 2001) absent?
Questions
1. Which state is the largest producer of hazardous waste?
2. Which has the most hazardous waste generators?
3. Conduct an internet search of a company from any state and determine what are their waste chemicals.
Data
http://www.epa.gov/epaoswer/hazwaste/data/biennialreport/
Large quantity generator
Data
Sources
• Express waste emission or ‘sources’ in mathematic terms:
Pulse (instantaneous) – occurs over a small time scale
e.g.dumpng of x amount of pollutant into a river
Step (continuous) – occurs over long time scales (indefinite)
e.g. constant release from industry, landfill lechate, sewage tretment works
Two extremes of input functions. Mathematicians can build an input function to suit the scenario
End
• Review
Historical Modeling Examples
• Surface water– BOD waste to streams– Rhine river - pestcides + metals– Tisza river - cyanide + metals
• Groundwater– Deep well - trichloroethylene– Swiss landfill - chloroanilines
• Atmosphere– Bhopal - methyl isocyanate– Chernobyl - radionuclides
Surface Water
Historical Modeling ExamplesBOD Waste Release in Streams
• BOD waste (organic matter)release to natural systems
• O2 used up in oxidizing waste
• Anaerobic conditions
• Recovery with natural aeration and all BOD oxidized
DO concentration profile of a stream receiving sewage waste
DO plummets as MO consume organics
Historical Modeling ExamplesBOD Waste Release in Streams
• Sewage treatment plant added
• Assume 95 % BOD removed
• DO is only moderately affected by treated wastewater
95% treated waste
European Rivers
http://www.euroatlas.com
Rhine
Tisza
Danube
Newspaper Coverage
‘One of the worst chemical spills ever…’
Anonymous
• Fire at Sandoz Ltd. released pesticides, solvents and dyes
• Pulse release– 10 days to travel to
North Sea– ½ million fish killed– Disulfoton (pesticide)
Capel et al, 1988
Historical ExamplesRhine River, 11-01-86
Historical Examples Rhine River, 11-01-86
• Movement and flushing of disulfoton
Disulfoton at monitoring stations
Bell curve is characteristic of pulse release
Diluted and degaded downstream
• Model fit to data to better understand how pollutants move through the system
• Used to predict downstream concentrations of later releases
• Useful for shutting down drinking water supplies
New York Times, February 14, 2000
New York Times, February 14, 2000
‘…the worst disaster since Chernobyl’ (Cunningham, 2005)
Historical ExamplesTisza River, 01-30-00
• Baia gold mine (CLGR)
• Cyanide (acute) and heavy metal (chronic) waste released Tisza – Danube – Black Sea
80% fish died + wildlife
• Romania had no international treaties with Hungary, decided it was not responsible for damages (Schaefer, 2000)
http://www.mineralresourcesforum.org/incidents/BaiaMare/index.htm
• 01-31-00• Tailings pond overflowed (more rain than expected)• Treated with Sodium hypochloride to remove CN• (Korte et al., 2000; Soldan et al., 2001)
Groundwater
Historical ExamplesDeep Well Injection
• 93 m well drilled in 1953 for hazardous waste
• Groundwater level is 63 m
• 133,000 L trichloroethylene (TCE), organic sludge, metals and radioactive waste
• Step-model fit to TCE measurements
– Based on DNAPL (non-polar)
– Predicted 1994 levels 1000 to 3 ppb (MCL)
Predicted isoconcentration lines, 1994
Idaho National Engineering and Environmental Laboratory (INEEL)
• Predicted concentrations with no remediation for 2044
• Plume expands
Predicted isoconcentration lines, 2044
Historical ExamplesDeep Well Sites
Dunnivant et al., 1994
Historical ExamplesDeep Well Sites
• Results of removing source of TCE
• Significantly improves groundwater quality
• Plume migrates down slope and is diluted
• Must weigh cost of cleanup, health rirsks of drinking contaminated supply and remediation work
Predicted isoconcentration lines, 2044
Historical ExamplesSwitzerland 1985
• Sondermulldeponie landfill• Nitrobenzene liquid waste in steel drums buried in sawdust
(absorbant)• 1985 discovery of reduced aromatics (e.g. chloranilines) in GW
sites downslope• GW modeling using a step model would be easy for
nitrobenzene• Proposed that nitrobenzene compounds were reduced under
reducing conditions from oxidation of sawdust
Colombi, 1986
Schwarzenbach et al., 1990
Atmosphere
Historical ExamplesBhopal, 12-03-84
Historical ExamplesBhopal, 12-03-84
• Pesticide manufacturing plant• Methyl isocyanate (MIC) used to make carbamates
– Stored as liquid (refrig)– Unintentional water added caused chemical
reaction producing gas– Pulse release 13 ppm to 100 ppm
• 200 – 10,000 deaths, 300,000 injuries• No fate and transport or risk assessments conducted
before plant was built
Dave, 1985; Shrivastava, 1987
Historical ExamplesChernobyl, 4-86
Historical ExamplesChernobyl, 4-86
• See Env Phys
Physical versus Chemical
site conditions pHwind or water speed and direction EH
mixing (dilution; dispersion) solubilitysource mass and input function vapor pressurephase sorption phenomena
degradation rates
End
• Review
Further Reading
Journals and Reports• Anonymous (1987) Environmental Science and Technology, Vol. 21, p 5.• Capel, P.D., Giger, W., Reichart, R., and Warner, O. (1988) Accidental release of pesticides into the Rhine
River. Environmental Science and Technology, Vol. 22, pp. 992-997.• Colombi, C., (1986) Sondermulldeponie Kolliken wie weiter? Phoenix Int., Vol. 1, pp. 10-15.• Dave, J.M. (1985) The Bhopal methyl isocyanate (MIC) incident: A overview. In: Schiefer, H.D. et al.,
Proceedings of an International Symposium, Highly Toxic Chemicals: Detection and Protection Methods . Saskatoon, Saskatchewan, Canada, pp. 1-38.
• Dunnivant, F.M., Schwarzenbach, R.P., and Macalady, D.L. (1991) Reduction of substituted nitrobenzenes in aqueous solutions containing natural organic matter. Environmental Science and Technology, Vol. 26, pp. 2133-2141.
• Dunnivant, F.M., Stromberg, G.J., Wiley, A.H., Hamel, C.M., and Leon, C.A. (1994) Feasability Study Report for Test Area North Groundwater Operable Unit 1-07B at the Idaho National Egineering Laboratory, EFFF-ER-10802, January 1994, Idaho Falls, ID.
• Schaefer, A. (2000) A disastrous cyanide spill could spawn liability reforms. Environmental Science and Technology, Vol. 34, A-203.
• Schwarzenbach, R.P.R., Stierli, R., Lanz, K., and Zeyer, J. (1990) Quinone and iron porphyrin mediated reduction of nitroaromatic compounds in homogeneous aqueous solution. Environmental Science and Technology, Vol. 24, pp. 1566-1574.
• US EPA (1989) Risk Assessment Guidance for Superfund Volume II, Environmental Evaluation Manual, Interim Final, EPA/540/1-89/001. Office of Emergency and Remedial Response, Washington, DC, p4.
Books
• Shrivastava, P. (1987) Bhopal: Anatomy of a Crisis. Ballinger Publishing Company, Cambridge, MA.
Links
• Basel Convention Data -http://www.basel.int/natreporting/2000/compII/cmpII.html
• EPA RCRA Data - http://www.epa.gov/epaoswer/hazwaste/data/biennialreport/
• Sag curves -http://environmentalet.hypermart.net/env2101/sagcurve.htm
• DO sag curve- http://www.math.sc.edu/~meade/ictcm98/DOsag2.html• Visual basic DO Program -
http://www.water.tkk.fi/wr/kurssit/Yhd-12.112/www_book/lm_26.htm• Rhine River Movie -
http://www.teachersdomain.org/resources/ess05/sci/ess/watcyc/rhine/index.html
• Modelling of point sources - http://scholar.google.com/url?sa=U&q=http://www.kosta.ch/~roland/pdf/Rheinmodellierung_Schadstofftransport.pdf
Movies
ENVS4450 Homework 1In 1986, a catastrophic fire broke out in a chemical warehouse in Schweizerhalle, a suburb of Basel, Switzerland. Hearing the sirens that blared during the night, residents of Basel thought that WW III had broken out. Unfortunately, the water used to put out the fire broke the dike surrounding the warehouse and tons of chemicals were washed into the Rhine River which was close to the warehouse. The principal toxic component was the insecticide disulfoton (C8H19PS4) [CAS 298-04-4]. The following data are relevant to the incident:
amount released in the spill, 3.3 metric ton (1 ton = 1000 Kg)mean flow velocity of the Rhine at Schweizerhalle, 1.0 m s -1
mean depth of the Rhine at Schweizerhalle, 5.0 mwidth of the Rhine at Schweizerhalle, 250 mduration of the spill, 12 h
a) Calculate the volumetric flow rate (discharge) of the Rhine River in m3 s-1 and L s-1.
b) Calculate the volume of water that flowed during the incident.
c) Estimate the concentration of disulfoton in the contaminated river water in μg L -1 and ppb.
d) Comment on the biological consequences of the accident. Useful data on the toxicity of disulfoton can be found at the EXTOX Web site.
e) The flow at Loblith, close to the mouth of the Rhine and 700 km downstream from Schweizerhalle, is 2300 m3 s-1. When the polluted plume reached Loblith, the concentration of disulfoton was 2.7 μg L -1. Was dilution a major source for the reduction of the disulfoton concentration or were other factors responsible? Briefly discuss.