Environmental Modeling Chapter 1: Sources and Types of Pollutant (why we need modeling, and...

transcript

Environmental Modeling

Chapter 1:Sources and Types of Pollutant

(why we need modeling, and historical contamination events)

“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

Inorganic OrganicRadioactive

Metals Metalloids Non-metals

Toxic Non-Toxic

TransitionMetals

HeavyMetals

Chemical type:

Make connections

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.

http://www.epa.gov/epaoswer/hazwaste/data/biennialreport/

Large quantity generator

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

• 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

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

‘…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

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

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

• 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

• 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

• 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.

• Shrivastava, P. (1987) Bhopal: Anatomy of a Crisis. Ballinger Publishing Company, Cambridge, MA.

• 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.

Environmental Modeling Chapter 1: Sources and Types of Pollutant (why we need modeling, and...

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