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Environmental Environmental Chemistry CChemistry C
Focus on SoilFocus on Soil
Lin WozniewksiLin Wozniewksi
[email protected]@iun.edu
SafetySafety
Students must wear:Students must wear: Closed shoesClosed shoes Slacks or skirts that come to the anklesSlacks or skirts that come to the ankles Sleeved ShirtSleeved Shirt Lab coat or lab apronLab coat or lab apron Indirect vent or unvented chemical splash proof Indirect vent or unvented chemical splash proof
goggles. No impact glasses or visorgogs are goggles. No impact glasses or visorgogs are permittedpermitted
Students can bringStudents can bring
CalculatorCalculator 1 sheet of paper on which anything 1 sheet of paper on which anything
handwritten is acceptablehandwritten is acceptable A writing instrumentA writing instrument
Supervisors will provideSupervisors will provide
The instrumentsThe instruments The materials to testThe materials to test Any calibration curves necessaryAny calibration curves necessary Any other testing materials necessaryAny other testing materials necessary Instructions on how to use instrumentation or Instructions on how to use instrumentation or
test kits.test kits.
Main FocusMain FocusSoil NutrientsSoil NutrientspHpHFertilizersFertilizersEffects of soil Effects of soil
TemperatureTemperatureDifference Difference
between sand, between sand, silt, & claysilt, & clay
What plants needWhat plants needPorosity, water Porosity, water
retention, & retention, & permeabilitypermeability
ContaminantsContaminantsRemediationRemediation Impacts of over Impacts of over
fertilizationfertilization
Main Focus
Gas Spectrogram retention timesGas Spectrogram retention timesMass SpecMass SpecDilutions, unit conversions & Dilutions, unit conversions &
Stoichiometric calculations Stoichiometric calculations How to prepare students How to prepare students ResourcesResources
Soil NutrientsSoil Nutrients 3 3 Main classes of Main classes of
nutrientsnutrients Absolutely necessaryAbsolutely necessary
NitrogenNitrogen PhosphorousPhosphorous PotashPotash
VitalVital Calcium Calcium MagnesiumMagnesium SulfurSulfur
TraceTrace Iron, Manganese, Zinc, Iron, Manganese, Zinc,
Boron, Copper, Boron, Copper, MolybdenumMolybdenum
Chlorine, Silicon, Chlorine, Silicon, Nickel, CobaltNickel, Cobalt
Soil TestingSoil Testing
Test kits are available at local garden centers and Test kits are available at local garden centers and Sears costing from ~$3-5. Often enough material for Sears costing from ~$3-5. Often enough material for several tests are includedseveral tests are included
Numbers are not usually given, just very low, low, Numbers are not usually given, just very low, low, optimum, and above.optimum, and above.
Even professional soil testers will give not only the Even professional soil testers will give not only the numbers (which will vary from laboratory to numbers (which will vary from laboratory to laboratory and hence are unreliable) will also give laboratory and hence are unreliable) will also give the results in terms of very low, low, optimum, high.the results in terms of very low, low, optimum, high.
pHpH
Many plants need a slightly acidic soilMany plants need a slightly acidic soil The natural pH of most water is about 6 The natural pH of most water is about 6
because of the carbon dioxide dissolved in it.because of the carbon dioxide dissolved in it. Some flowers like hydrangeas have different Some flowers like hydrangeas have different
colored flowers in different pH soilscolored flowers in different pH soils Many plants produce natural indicators that Many plants produce natural indicators that
change colors in different pH’schange colors in different pH’s
Calcium and MagnesiumCalcium and Magnesium
Both Calcium and Magnesium are vital to Both Calcium and Magnesium are vital to proper plant growthproper plant growth
Neither are tested for in a standard NPK soil Neither are tested for in a standard NPK soil test kittest kit
Can be tested for by testing a digested sample Can be tested for by testing a digested sample
RemediationRemediation
To raise the pH of acidic soils (below pH 5.8), To raise the pH of acidic soils (below pH 5.8), add lime (limestone)add lime (limestone)
To lower the pH of basic soils (above pH 8.3) To lower the pH of basic soils (above pH 8.3) that do not contain free carbonate, add sulfur.that do not contain free carbonate, add sulfur.
Since limestone is a combination of calcium Since limestone is a combination of calcium and magnesium carbonate, it can be added to and magnesium carbonate, it can be added to increase the carbonate level if necessary.increase the carbonate level if necessary.
FertilizersFertilizers NPK Fertilizers are only concerned with the 3 NPK Fertilizers are only concerned with the 3
Absolutely Necessary ingredientsAbsolutely Necessary ingredients Nitrogen in the form of Ammonia (NHNitrogen in the form of Ammonia (NH33) and Nitrate ) and Nitrate
(NO(NO33--))
Phosphorous (Usually in the form PPhosphorous (Usually in the form P22OO55))
Potash (KPotash (K++) (Usually as K) (Usually as K22O)O)
The numbers on the bag tell the weights of each The numbers on the bag tell the weights of each ingredient, in that orderingredient, in that order
There are lots of different fertilizers for various There are lots of different fertilizers for various purposespurposes
FertilizersFertilizersMaterial N P2O5
(%)K2O
MgO S
Ammonium Nitrate 35 0 0 0 0
Ammonium Sulfate 21 0 0 0 24
Calcium Nitrate 15.5 0 0 0 0
Diammonium Phosphate 18 46 0 0 0
Monoammonium phosphate 11 52 0 0 0
Muriate of Potash 0 0 60 0 0
Potassium Nitrate 13.5 0 44 0 0
SKMG or SULPOMAG 0 0 22 18 22
Sulphate of Potash 0 0 50 0 18
Single Super Phosphate 0 22 0 0 14
Triple Super Phosphate 0 46 0 0 0
Urea 46 0 0 0 0
Effect of TemperatureEffect of Temperature Water has a very high specific heat because of Water has a very high specific heat because of
the hydrogen bondingthe hydrogen bonding This means it can store a lot of heat in the This means it can store a lot of heat in the
bondsbonds Moist soil will not warm up as fast as dry soilMoist soil will not warm up as fast as dry soil Dry soil will not cool down as fast as wet soilDry soil will not cool down as fast as wet soil Most plants prefer an optimal temperature for Most plants prefer an optimal temperature for
maximum growth-they will not grow properly maximum growth-they will not grow properly if too hot or too coldif too hot or too cold
What Plants NeedWhat Plants Need
The Nitrogen is used for green leavesThe Nitrogen is used for green leaves The Phosphorus is used for strength and the The Phosphorus is used for strength and the
root systemroot system The Potash is used for fruits.The Potash is used for fruits. Most plants need a neutral pH around 6-6.5Most plants need a neutral pH around 6-6.5 Plants need balanced nutrition and not just Plants need balanced nutrition and not just
NPK fertilizersNPK fertilizers
Fertilizer Good or BadFertilizer Good or Bad
A good fertilization plan can be more A good fertilization plan can be more beneficial for the environment than no beneficial for the environment than no fertilizationfertilization
A properly applied fertilization program will A properly applied fertilization program will promote plant growth which will prevent soil promote plant growth which will prevent soil erosionerosion
Proper fertilization means only applying what Proper fertilization means only applying what is necessary and not over applyingis necessary and not over applying
Pollutant or Contaminant?
It is a pollutant if it is supposed to be there, but the substance is present in higher quantity than it should be. Fertilizers, some ions, etc. Sometimes metals are thought of as contaminants, but
many soils contain arsenic and mercury naturally It is a contaminant if it is not supposed to be there
at all Plastics
PollutantsPollutants
Are metals pollutants or trace nutrients?Are metals pollutants or trace nutrients? It depends on the concentrationsIt depends on the concentrations Some copper, iron, etc. are necessary for plant Some copper, iron, etc. are necessary for plant
development.development. Plants take the metal ions up in their structure Plants take the metal ions up in their structure
and can be used to bio-remediate area, but then and can be used to bio-remediate area, but then the plants can not be used for food.the plants can not be used for food.
Remediation Remediation depends on source and size of problem Soil bacteria will digest many petroleum spills if the
spill is not large scale or buried deeply Underground storage tank leaks often have to be
dug out so bacteria can get to petroleum Clay will retain heavy metal contamination for long
periods Plants can be used to bio remediate soil Chemical reactions can be used for some
remediation Electrokinetic remediation using acetic acid has
achieved some success
Source of Pollutant/Contaminant Point Source – Used to be the biggest source
of pollution. This would be a single plant, a chemical spill, a single farmer, etc. Legislation has almost eliminated this type of pollution
Non Point Source – Now the biggest source of pollution. This would be petroleum products dripping off of vehicles, road salt, fertilizer from residential areas, etc. This is much harder to control
Mass Spec Most questions will either be
Match the picture Determine the weight of some part Determine the relative abundance of some part
Graphs have the mass of the components that the mass spectrometer
has broken the compound up into on the x-axis The relative abundance on the y-axis
GC Spectrograms Used to separate components of a mixture The further right a peak is, the longer it is
retained in the column This is usually because it has a higher affinity
for the stationary phase Or it has a lower affinity for the mobile phase The higher the peak is, the higher the
concentration of that particular component of the mixture
Preparation of Soil SamplesPreparation of Soil Samples Normally to test for metal ions, the soils must be Normally to test for metal ions, the soils must be
refluxed in concentrated nitric acid for about 24 refluxed in concentrated nitric acid for about 24 hours to remove the metals to be tested forhours to remove the metals to be tested for
Then the liquid is diluted.Then the liquid is diluted. Most of the ions are not colored and therefore need Most of the ions are not colored and therefore need
a reagent that when combined with the metal ions a reagent that when combined with the metal ions will be colored so the solution can be put in a will be colored so the solution can be put in a colorimeter.colorimeter.
Since this is time consuming and dangerous, it may Since this is time consuming and dangerous, it may be advantageous to “fake” the materials to be tested be advantageous to “fake” the materials to be tested for.for.
Preparation of Test MaterialsPreparation of Test Materials Food coloring makes an extremely good coloring Food coloring makes an extremely good coloring
agent.agent. If dilute enough, students would be hard pressed with the If dilute enough, students would be hard pressed with the
naked eye to tell the difference between a liter of water naked eye to tell the difference between a liter of water with a drop of red food coloring and an iron(III) solution with a drop of red food coloring and an iron(III) solution with phenanthrolene addedwith phenanthrolene added
Students would have a tough time telling with the naked Students would have a tough time telling with the naked eye the difference between a solution of copper(II) ion eye the difference between a solution of copper(II) ion and a dilute solution of water and blue food coloring. and a dilute solution of water and blue food coloring.
Black food coloring makes an extremely good base Black food coloring makes an extremely good base to hide other colors in.to hide other colors in.
Basic Types of Soil Sand – Largest particles – virtually no organic
material - try to form a 1” ball of moist soil in your hand & if it feels gritty & won’t stay together it is a sandy soil
Silt – Smaller particles, more organic material – considered most fertile - less gritty ball than sand, more gritty than clay, ball crumbles
Clay –Smallest particles - if the 1” ball feels smooth, plastic, requires lots of pressure to form, stays together well & forms ribbons between your fingers, it is clay soil
Other Soil types
Loam –made of some sand, silt, and clay - if the 1” ball feels partially smooth, partially gritty & forms a ball that easily crumbles it is loamy soil
Peat Soil – dead plant material – very acidic Chalky Soil – has a large number of stones and
is very alkaline
Porosity A measure of the void spaces in the soil as a
percentage of the soil Porosity = void volume/soil volume Sandy soil ~.43-.36 Clay soil ~ .58-.51 Seems counterintuitive Example
If 1 m3 of soil is actually .7 m3 of soil and .3 m3 of air and water
Porosity = .3 m3/1 m3 = .3 (sandy soil)
How to Measure Porosity
Easiest method is to measure a volume of the soil
Measure an amount of water Pour water into soil and collect that which runs
through Pour volume = Original volume of water –
volume collected
Permeability
The ability of the soil to transmit fluids In other words how quickly the water can flow
through the soil
1 meter of Will take _ to drain 1liter of water
Gravel 2 minutes
Sand 2 hours
Silt 200 days
Clay 200 years
How to Measure Permiability
Take a sample of soil .1 meter deep in a sieve or container with a drain
Take a volume of water Time how long it takes for the water to come
out the bottom of the container
Water Retention
Related to particle size, porosity, and permeability
Defined as water content as a function of matric pressure
A centrifuge is preferred to measure matric pressure
Often measured at the pore size in porosity measurements
Impacts of Over fertilization The main impact of over fertilization is the runoff
into streams and rivers The runoff into the streams and rivers causes
unnatural algae blooms Algae blooms take dissolved oxygen out of the
bodies of water When the dissolved oxygen is taken out of the
water, fish and macro invertebrates die Then you also have the problem of over production
of fertilizer at plants with the associated environmental costs
Calculations-Dilutions
Many fertilizers are liquids They are sold in concentrated forms and
require dilutions before use Students should be able to do calculations
involving dilutions
Calculations-Unit Conversions
Parts per notation is a measure of concentration Students need to be able to convert from one type
of concentration to another pph = parts per hundred = % ppm = parts per million = 1/1,000,000 = 1X10-6
Stoichiometry
Many contaminating heavy metals can be oxidized to remediate.
Oxides of most metals are insoluble in water and therefore removed from ecosystem
Oxidation can be by means of air injection or injection of strong oxidizer like ozone or permanganate
Some petroleum products are thermally burned
How To Prepare StudentsHow To Prepare Students
Practice Practice In teamsIn teamsWith soil test kitsWith soil test kitsWith instrumentsWith instrumentsWith calibration curvesWith calibration curvesDoing unit conversions, etcDoing unit conversions, etc
Make notesMake notes
How to Prepare StudentsHow to Prepare Students
Have students researchHave students research FertilizersFertilizers Plant nutrientsPlant nutrients Environmental effectsEnvironmental effects Trace nutrientsTrace nutrients ChromotographyChromotography
ResourcesResources Nutrient depleation Nutrient depleation
http://www.youngevity.ca/misc/mineral_depletion.php
Activity - Activity - http://www-tc.pbs.org/saf/1301/teaching/teach2.pdf
With Acid Rain With Acid Rain http://www.eurekalert.org/pub_releases/2004-03/uom-ars032604.php#
Tomato Plant nutrient requirements Tomato Plant nutrient requirements http://www.wikihow.com/Grow-a-Tomato-Plant
Reading Fertilizer Labels Reading Fertilizer Labels http://www.wikihow.com/Read-a-Fertilizer-Labelhttp://www.wikihow.com/Read-a-Fertilizer-Label
ResourcesResources Effects of nutrient deficiency on plants Effects of nutrient deficiency on plants
http://www.uga.edu/vegetable/home.htmlhttp://www.uga.edu/vegetable/home.html
Soil Testing http://www.lowes.com/lowes/lkn?Soil Testing http://www.lowes.com/lowes/lkn?action=howTo&p=LawnGarden/soiltest.htmlaction=howTo&p=LawnGarden/soiltest.html
Soil Test Kits http://www.shopping.com/xDN-Soil Test Kits http://www.shopping.com/xDN-garden--soil_testing_kits-price_range_10_20garden--soil_testing_kits-price_range_10_20
Fertilizer Numbers Fertilizer Numbers http://www.agroservicesinternational.com/index.htmhttp://www.agroservicesinternational.com/index.htmll
RescourcesRescources
Instrument labsInstrument labshttp://education.ti.com/educationportal/http://education.ti.com/educationportal/
activityexchange/activity_list.do?cid=usactivityexchange/activity_list.do?cid=usSource for all sorts of mass spectra & GCSource for all sorts of mass spectra & GChttp://riodb01.ibase.aist.go.jp/sdbs/cgi-bin/http://riodb01.ibase.aist.go.jp/sdbs/cgi-bin/
cre_index.cgicre_index.cgihttp://webbook.nist.gov/chemistry/name-ser.htmlhttp://webbook.nist.gov/chemistry/name-ser.html Soil in GeneralSoil in Generalhttp://techalive.mtu.edu/meec/module06/Porosity.htmhttp://techalive.mtu.edu/meec/module06/Porosity.htm