Managing the Atmosphere Unit 7 AICE Environmental Management

Managing the Atmosphere Unit 7 AICE Environmental Management Topic 7.3 Managing Air Pollution & Ozone Depletion Strategies for Managing Air Pollution Reduction of Fossil Fuel Use Reduction of Emissions: SOx, NOx, VOCs, and Particulate Matter Restriction of Vehicle Use in...

Managing the Atmosphere Unit 7 AICE Environmental Management Topic 7.3 Managing Air Pollution & Ozone Depletion Strategies for Managing Air Pollution Reduction of Fossil Fuel Use Reduction of Emissions: SOx, NOx, VOCs, and Particulate Matter Restriction of Vehicle Use in Urban Areas Legislation  Reduction of Fossil Fuel Use Reduce demand of private car use. Mass Transit or Ride Sharing Drive Less and Walk/Bike/Bus More Reduce consumption of electricity through building design & renewable energy sources. small scale green power on city buildings e.g. solar, wind, locale power stations away from urban areas. Renewable, non-pollution emitting energy sources (solar, wind, hydro). Alternative (nuclear) energy during transition to renewable energy dependency. Eat local. Eat more plants, less meat - less processing.  Reduction of SOx (Sulfur Dioxide) Emissions Flue Gas Desulfurization Dry Scrubbers Wet Scrubbers A flue is a smokestack.  Reduction of SOx (Sulfur Dioxide) Emissions Dry Scrubbers Made up of a large column/tube/pipe filled with chemicals that absorb or neutralize oxides (NOx, SOx, VOCs) from exhaust streams (emissions). Calcium oxide is a common dry scrubber additive which reacts with SO2 to form calcium sulfite.  Reduction of SOx (Sulfur Dioxide) Emissions Wet Scrubbers May involve chemical agents that absorb or neutralize NOx, SOx, VOCs, but also include mist nozzles that trap PM in water droplets as well. Mist droplets with pollutants and PM trapped in them fall to bottom of scrubber or get trapped at the top by mist eliminator. Sludge collection system traps polluted water for disposal.  Reduction of SOx (Sulfur Dioxide) Emissions Hydrodesulfurization (HDS) or Hydrotreating A catalytic chemical process widely used to remove sulfur compounds from refined petroleum products such as gasoline or petrol, jet fuel, diesel fuel, and fuel oils. One purpose for removing the sulfur is to reduce the sulfur dioxide emissions resulting from using those fuels in automotive vehicles, aircraft, railroad locomotives, ships, or oil burning power plants, residential and industrial furnaces, and other forms of fuel combustion. Reduction of SOx (Sulfur Dioxide) Emissions Hydrodesulfurization (HDS) or Hydrotreating Facility  Reduction of NOx (Nitrogen Oxide) Emissions Catalytic Converters have been around since 1975. This device converts harmful pollutants such as carbon monoxide and oxides of nitrogen from a combustion engine’s exhaust into less harmful molecules like CO2, water, and nitrogen. Key point: CO2 is NOT a pollutant!! Reduction of VOCs (Volatile Organic Compound) Emissions: Sources Sources of VOCs cleansers and Household products, disinfectants moth repellents and air including: fresheners paints, paint strippers stored fuels and and other solvents automotive products wood preservatives hobby supplies aerosol sprays dry-cleaned clothing pesticide Reduction of VOCs (Volatile Organic Compound) Emissions: Steps to Reduce Exposure Steps to Reduce Exposure Increase ventilation when using products that emit VOCs. Meet or exceed any label precautions (including proper disposal). Do not store opened containers of unused paints and similar materials within the school. Formaldehyde, one of the best known VOCs, is one of the few indoor air pollutants that can be readily measured.  Reduction of Particulate Matter Emissions Electrostatic Precipitators Precipitators function by electrostatically charging particles in the gas stream. The charged particles are attracted to and deposited on plates or other collection devices. The treated air then passes out of the precipitator and through a stack to the atmosphere. When enough particles have accumulated on the collection devices, they are shaken off the collectors by mechanical rappers. The particulates, which can be either wet or dry, fall into a hopper at the bottom of the unit, and a conveyor system transports them away for disposal or recycling. Reduction of Particulate Matter Emissions Electrostatic Precipitator Diagram Legislation: Local, National, & International Local and national governments can encourage individuals through educational campaigns and economic incentives. Energy Efficiency in Homes Reduction of Carbon Footprints Reduce, Reuse, Recycle Replacement of Chemical Fertilizers with Organic Fertilizers  Legislation: Local, National, & International Major International Agreements include: Geneva Convention on Long Range Transboundary Pollution – 1979 Controlling and reducing air pollution across borders by international corporations. Montreal Protocol – 1987 Ban and controlled use of CFCs to slow down ozone depletion. Rio Earth Summit – 1992 Agreement Agenda 21 passed with aim to cut environmental pollution and conserve resources and wildlife habitats.  Legislation: Local, National, & International Major International Agreements include: Kyoto Protocol Signed by over 100 countries to cut carbon dioxide emissions by 5%, compared with 1990 levels. Each HIC was allotted a target on emission reductions. Some LICs, such as China, were given no targets and were allowed to increase emissions. Gothenburg Protocol Aimed to reduce pollutants and levels of acid rain and tropospheric ozone.  Legislation: Local, National, & International Major International Agreements include: Copenhagen Conference – 2009 HICs and some LICs agreed to limits on greenhouse gas emissions. To assist LICs with the reduction, $30 billion was offered as aid by HICs, increasing to $100 billion by 2020. However, this was not legally binding. Paris Climate Conference – 2015 195 countries agreed to limit rise in global temperature to 2° C. European Union will cut carbon dioxide emissions by 40% by 2030, the U.S. by 28% by 2025, and China agreed their emissions will peak in 2030. Countries will meet every 5 years to discuss progress. Legislation: Polluter Pays Principle Polluter Pays The 'polluter pays' principle is the commonly accepted practice that those who produce pollution should bear the costs of managing it in order to prevent damage to human health or the environment. Topic 7.3 Practice Question Topic 7.3 Practice Question Using the map on the previous slide, respond to the following questions in the space provided on your note page. 1. Describe the distribution of deaths linked to urban air pollution shown on the map, AND suggest reasons for this distribution. (4) 2. Describe how the problem of air pollution can be solved by reducing urban vehicle traffic, AND explain two ways to reduce urban vehicle traffic. (6) Topic 7.4 Ozone Depletion  How Does Ozone Depletion Occur? Step 1: Chlorofluorocarbons (CFCs) from aerosols and refrigerants are unreactive compounds and are not broken down in the troposphere. Step 2: CFCs move into the stratosphere and break down in the presence of ultraviolet light to release a chlorine atom. Step 3: Rapid reactions between chlorine atoms and ozone breaks down ozone (O3) into oxygen (O2), causing ozone depletion. How Does Ozone Depletion Occur? Step 4: Chlorine atoms remain in the stratosphere and can continue to destroy ozone. How Is Ozone Measured? Ozone concentration is measured using the Dobson Unit. An ozone hole is an area where the average concentration of ozone is below 100 Dobson Units. Watch “Introduction to the Dobson Unit” and take notes in space provided. https://www.youtube.com/watch?v=kLkzruiX KtQ  Impacts of Increased UV Radiation Deterioration of the ozone layer results in an increase in harmful UV radiation reaching Earth’s surface. Specific impacts include: Cataracts and skin cancer. Decreased crop yield. Decreased biodiversity of terrestrial (forests) and aquatic (plankton) ecosystems. Degradation of materials used in clothing and construction.  Montreal Protocol The Montreal Protocol has been the most successful international agreement in reducing/eliminating the production and use of ozone depleting substances. Watch “NASA Sees Definitive Evidence of the Montreal Protocol’s Success” and take notes in the space provided.  Impacts of Alternatives to Ozone Depleting Substances Alternatives to chlorofluorocarbons (CFCs) include: Hydrofluorocarbons (HFCs): Hydrofluorocarbons (HFCs) are greenhouse gases (GHGs) commonly used by federal agencies in a wide variety of applications, including refrigeration, air-conditioning (AC), building insulation, fire extinguishing systems, and aerosols. HFCs have high global warming potential (GWP), raising concern about their impacts as they become increasingly used as replacements for ozone- depleting substances (ODS), and as economic growth spurs demand for new equipment, especially in the refrigeration/AC sector. Impacts of Alternatives to Ozone Depleting Substances Alternatives to chlorofluorocarbons (CFCs) include: Fluorinated Gases (F-GHGs): include the most potent and longest lasting greenhouse gases emitted by human activities. These are emitted as a byproduct of aluminum production and electronics manufacturing. Experimental Evidence & the Ozone Destruction Hypothesis Experimental evidence is important to the development of scientifically sound hypotheses. Experiments and research by Rowland and Molina took time and the accumulation of ample evidence/data collected by them as well as other scientists.  Experimental Evidence & the Ozone Destruction Hypothesis The Work of Rowland and Molina Initially the main hypothesis was not accepted. Some of the auxiliary hypotheses were not supported by experimental evidence. The hypothesis led to further research and data collection by other scientists, which confirmed that CFCs are ozone depleting. Watch PBS “Ozone Hole – How We Saved the Planet” and complete the worksheet. https://www.pbs.org/video/ozone-hole-how-we-saved-the-pl anet-ttwe2l/ Topic 7.4 Practice Questions