Prof. R. Shanthini Jan 14, 2012 Module 04 Energy Impacts (continued) Ecological impacts of energy generation from non-renewable energy sources in global & local scale and probable mitigation measures Global scale: greenhouse gas emissions, global warming, and climate change Local scale: acid rain, particulate pollution, thermal pollution and related impact, fresh-water exploitation, and altering land use

Prof. R. Shanthini Jan 14, 2012 Acid Rain (or Acid Deposition)

Prof. R. Shanthini Jan 14, 2012 Acid Rain (Sodium hydroxide) Measuring acidity

Prof. R. Shanthini Jan 14, 2012 What causes acid rain - Acid rain occurs when sulfur dioxide (SO 2 ) and/or nitrogen oxides (NO x ) gases react in the atmosphere with water, oxygen, and other chemicals to form various acidic compounds. - The result is sulfuric acid and/or nitric acid. - SO 2 comes mostly from coal burning and volcanic eruptions. - NO x comes from all types of fossil fuel burning, fertilizer usage and lightning. - These gases can be carried by wind over hundreds of kilometers in the atmosphere.

Prof. R. Shanthini Jan 14, 2012 Acid rain pathway

Prof. R. Shanthini Jan 14, How acid rain alters nature

Prof. R. Shanthini Jan 14, Impact of acid rain - Increased concentration of H + ions (i.e. acidic) and increased aluminium concentration in the surface water harm fish and other aquatic animals. - Some soil microbes are killed by acids. - Loss of essential nutrients (such as calcium and magnesium) from soil caused by acids changes the soil chemistry haring the growth of sensitive species. -High altitude forests (often surrounded by clouds and fogs) are damaged. - Acid rain damages limestone and marble based buildings and statues, which contains large amount of calcium carbonate. Sulfuric acid, when combined with calcium carbonate, forms pH-neutral calcium sulfate, CO 2 and water. Forest Die back at Horton Plains

Prof. R. Shanthini Jan 14, 2012 Liming of rives and lakes - Powdered limestone has been added to lakes and rivers ("liming") to neutralise the water. - Liming is expensive and its effects are only temporary. - Norway and Sweden have successfully used liming to help restore lakes and streams in their countries. - A major liming programme has been taking place in Wales where 12,000 km of its waterways were acidified. - In 2003 liming of the river Wye (UK) led to a return of the salmon which had completely disappeared in 1985.

Prof. R. Shanthini Jan 14, 2012 International treaties Sulphur Emissions Reduction Protocol under the Convention on Long-Range Transboundary Air Pollution The convention opened for signature on

Prof. R. Shanthini Jan 14, 2012 Control of sulfur dioxide from power plants Flue-gas desulfurization (FGD) is used in coal power plants to remove sulfur-containing gases from their stack gases.

Prof. R. Shanthini Jan 14, 2012 Control of sulfur dioxide from power plants

Prof. R. Shanthini Jan 14, 2012 Control of sulfur dioxide from power plants

Prof. R. Shanthini Jan 14, 2012 Real GDP per capita Ambient SO 2 level EKC for sulfur dioxide

Prof. R. Shanthini Jan 14, 2012 It contains a ceramic structure coated with a metal catalyst (platinum, rhodium, palladium and/or gold mixed with the more traditional catalysts). In the first stage, platinum and rhodium catalysts help reduce the NO x emissions by ripping the nitrogen atom out of the molecule and holding on to it and freeing the oxygen in the form of O 2. The nitrogen atoms bond with other nitrogen atoms that are also stuck to the catalyst, forming N 2. In the second stage, the unburned hydrocarbons and carbon monoxide are oxidized over a platinum or palladium catalyst. Catalytic convertor

Prof. R. Shanthini Jan 14, 2012 Easy reference sites

Prof. R. Shanthini Jan 14, 2012 Particulate Pollution

Prof. R. Shanthini Jan 14, 2012 Particulate matter

Prof. R. Shanthini Jan 14, Particulate matter pollution

Prof. R. Shanthini Jan 14, Particles in vehicle emissions consist mainly of carbon but also include fibres, metal fragments and soluble salts. - The particles carry carcinogenic polycyclic aromatic hydrocarbons (PAH) and other volatile, and also carcinogenic, organic compounds (VOC) on their surface. - Diesel particles, which are mainly less than 1 µ (micron) in diameter and have an median diameter of about 0.2 µ (200 nanometers), are by far the most dangerous of the commonly found particles. Particulate matter pollution

Prof. R. Shanthini Jan 14, Particulate matter pollution

Prof. R. Shanthini Jan 14, Within several hours of sunrise, most of the atmospheric carbon (jagged bits of fresh soot) quickly become coated with a spherical shell of other chemicals, particularly sulfate, nitrate, and organic carbon, through light-driven chemical reactions. - The coating acts like a lens and focuses the light into the center of the particle, enhancing warming. - Measurements showed that in the atmosphere the lens-like shell of sulfate and nitrate enhances absorption of light by coated soot particles 1.6 times over pure soot particles. Particulate matter pollution