Presentation on theme: "Studying Ozone and Air Quality"— Presentation transcript:
1Studying Ozone and Air Quality Steve SchneiderDeborah CarlisleGoals :Provide students with project work that will educate them about air quality with O3 and CO2 (smog and emissions)
2Measuring Ground-level Ozone VOC’s + NOX + sunlight O3Motor vehicles are the single largest contributor to ground-level ozone.O3 levels above 120 ppb (by volume) are considered unhealthy. They can be generated by some electrical equipment or from photochemical reactions with smog:
3Measuring Ground-level Ozone O3 levels above 120 ppb are considered unhealthy. They can be generated by some electrical equipment or from photochemical reactions with smog:VOC’s + NOX + sunlight O3Motor vehicles are the single largest contributor to ground-level ozone.In this project we are adapting the relatively easy-to-make Schoenbein papers for classroom use, and using ADI to analyze the color changes quantitatively.Color chart allows for a general
4Index values in ppb 1000ppb = 1ppm *Crop last column (rt click – check Fx) – Omit and add #’s to USA slide
5Useful Sites http://www.weather.gov/aq/sectors/nemetro.php#tabs Interesting data based on scattered data – based on siteBUT local sources are very relevant and use strip to verify certain areas such as bus stops,Add Mass DEP
6Commercial Papers: Ecobadge, Ozone badge We were interested in using this to test air quality – started with commercial papersLots of variability up to 50 +ppbOzone solutions and Vistanomics
7Findings:Commercial cards had significant variability and were expensive.Researched making Schoenbein papersInexpensive and safe to make
8Schoenbein PapersOzone was discovered by C.F. Schoenbein in He developed an ozone-sensitive test paper that was widely used historically, and more recently in classrooms.The standard protocol for using the papers calls for an 8-hour exposure to the air out of direct sunlight. Various studies have shown a dependence on humidity, and there are a variety of recommendations for moistening the strips prior to exposure.Control low O high O3exposure exposureThey are relatively easy to make – takes some practice to get an even application of the chemical across the entire filter paper.
9HistoryDespite the method's early limitations, starting in the mid-1800s, more than 300 stations recorded ozone exposures in countries such as Austria, Australia, Belgium, England, France, Germany, Russia, and the United States.Using Schoenbein papers –Why were people concerned (in London) – develop a bit of history. IndustrialBlack smog of London 1852 thousands died of smog inhalaiton due to coal combustion
10Learning Goals :Analyze different relative amounts of ozone found in various locations using test results.Understand that ozone is found near the earth’s surface (ground level) in the troposphere as well as the stratosphere.Understand that ozone test strips/Schoenbien paper detect ozone gas through a chemical reaction that is caused by ozone in the air.Use technology to more precisely analyze relative color changes obtained with ozone test strips.For students
11Some Testing Ideas:Test for ozone at different times of day and look for patterns. When are ozone concentrations the highest?Test for ozone in various locations and see what areas are the highest.Look at the effects of wind patterns on ozoneStudents research and brainstorm where ozone might be found and what equipment/machines produce ozoneFor students
12Making Schoenbein Papers Refer to handout – I’ll do demonstrateExplain protocol – about 30 min.
13Classroom Use Made Easier: 1. Test strips can be stored in a double plastic zip lock bag, until you are ready to read your results.2. To look at results simply dip your exposed test strip in a beaker of water. You will see a visible color change.3. Compare the relative colors to the control.4. Use digital analysis to measure RGB values and compare between test strips.Edit Color chart allows for a general
15Testing Ozone Levels Groups of 4 Select a test site Things to Consider Avoid direct sunlightFree air circulation around your stripRun a control with your groupLabel an index card with date/time/locationTime required to hang strips and test – 20 min.
16Outdoor exposureDistribute teacher notes, and have them turn to pg 4 in handout “Use of Test Strips”
17Carrying Out the Experiment: Discuss experimental design in your groups to come up with a plan for testingRun tests (place test strips and control)Collect test strips and place in zip-lock baggiesReturn to lab and expose strips by dipping in waterPhotograph test stripsData Analysis and share resultsSee – handoutOutline this before you begin
19How do Ozone Test Strips Work?Ozone is a strong oxidizer. It rapidly reacts with the iodide ion, I- in the KI salt applied to the filter paper.KI + H2O + O3 I2 + O2 + K+I2 + I- + starch I3- + starchLast step : I3- (linear)+ starch (helix)(Turns Blue)Combination of I3- and helix causes light reflection to be in the blue/violet range of visible spectrum
26National Science Education Standards Science as Inquiry: Grades 5-8 and 9-12Ability to perform scientific inquiry, understanding about scientific inquiryScience and Technology: Grades 5-8 and 9-12Understanding about science and technologyScience in Personal & Social Perspectives: Grades 9-12Environmental quality, changes in environments