CEE 210 Environmental Biology for Engineers Southern Illinois University Carbondale 5 5 2010 Objectives Review discuss and identify the important features of Lecture Biogeochemical Cycles Water Cycle Carbon Cycle CEE 210 ENVIRONMENTAL BIOLOGY FOR ENGINEERS Nitrogen Cycle Rock Cycle Instructor L R Chevalier Department of Civil and Environmental Engineering Southern Illinois University Carbondale Environmental Biology for Engineers Water Cycle Water Cycle The hydrologic cycle describes the movement of water as water molecules make their way from the Earth s surface to the atmosphere and back again This system powered by energy from the sun is a continuous exchange of moisture between the oceans the atmosphere and the land Environmental Biology for Engineers NASA Goddard Space Flight Center Environmental Biology for Engineers Water Cycle Carbon Cycle Groundwater exists below the water table which divides unsaturated soil rock and sediments from saturated Environmental Biology for Engineers Lecture Instructor L R Chevalier Carbon is all around us This unique atom is the basic building block of life and its compounds form solids liquids or gases Carbon helps form the bodies of living organisms it dissolves in the ocean mixes in the atmosphere and can be stored in the crust of the planet A carbon atom could spend millions of years moving through this complex cycle Understanding how the carbon cycle is key to understanding Earth s biosphere Environmental Biology for Engineers p 1 CEE 210 Environmental Biology for Engineers Southern Illinois University Carbondale 5 5 2010 Carbon Cycle Carbon Cycle Video NASA Goddard Space Flight Center Environmental Biology for Engineers Environmental Biology for Engineers 7 1 GtC released from human activities Giga 1billion 3 2 GtC remain in the atmosphere Land use changes contribute 1 6 GtC 2 GtC diffuse in to world s oceans One of the most important nutrient cycles found in terrestial ecosystems Plants and animals need nitrogen Amino acids proteins nucleic acid Critical for primary production and decomposition Is the most limiting nutrient for plant growth 7p 7n 3p 3d 4s 4p 2p 2s In the atmosphere nitrogen exists as gas N2 1s Atmosphere is 78 80 nitrogen This store of nitrogen is a million times larger than the total nitrogen contained in living organisms Hund s Law not to scale 1s Significant storage is also in soils and oceans 2s 2p 3s 3p However this nitrogen is not available for biological use Need to understand the key processes of fixation mineralization nitrification and denitrification Environmental Biology for Engineers 3s Energy Fossil fuel burning releases roughly 5 5 gigatons of carbon GtC Nitrogen Atomic number 7 Nitrogen Cycle 2n2 electrons fill each orbit n is the before the letter Note that 4s has lower energy than 3d This orbit fills first Environmental Biology for Engineers Nitrogen Atomic number 7 Nitrogen Fixation Lightning Valence range Loss of five electrons 5 Gain of three electrons 3 7p 7n 1s 2s 2p 3s 3p Nitrogen gas N2 is zero valence Nitrogen can be fully reduced to ammonia NH3 or ammonium NH4 Can also be oxidized as NO3 nitrate Used by plants to make proteins and nucleic acid Nitrogen is oxidized Oxygen is reduced 1s22s22p3 Environmental Biology for Engineers Lecture Instructor L R Chevalier Tremendous amount of energy released by the electrical discharge breaks the bond between nitrogen atoms causing them to react with oxygen Environmental Biology for Engineers p 2 CEE 210 Environmental Biology for Engineers Southern Illinois University Carbondale 5 5 2010 Nitrogen cycle Mineralization Nitrogen Fixation Lightning N2 O2 2 NO nitric oxide The nitrous oxide formed combines with oxygen to form nitrogen dioxide Organic matter living or dead Ammonia NH3 2 NO O2 2NO2 Nitrogen dioxide readily dissolves in water to product nitric and nitrous acids Decomposition from bacteria and fungi Ammonium NH4 2 NO2 HNO3 HNO2 These acids readily release the hydrogen forming nitrate and nitrite ions which can be readily utilized by plants and micro organisms HNO3 H NO3 nitrate ions HNO2 H NO2 nitrite ions plants animals Environmental Biology for Engineers Environmental Biology for Engineers Nitrogen Cycle Nitrification Ammonium NH4 Nitrite NO2 Nitrosomonas autotrophic bacteria Nitrobacter Nitrogen Cycle Denitrification NO3 Nitrite NO2 Nitrate NO3 very soluble N2 or N2O nitrous gas Atmosphere However a significant amount of nitrogen is biochemically fixed to the soil by microorganisms Some moves into hydrologic cycle Environmental Biology for Engineers Anaerobic denitrification Environmental Biology for Engineers Nitrogen Fixation Nitrogen Cycle All nitrogen fixing organisms are prokaryotes bacteria Some live independently Others have symbiotic associations Legumes peas beans clover Environmental Biology for Engineers Part of a clover root system bearing naturally occurring nodules of Rhizobium Each nodule is about 2 3 mm long Lecture Instructor L R Chevalier Environmental Biology for Engineers p 3 CEE 210 Environmental Biology for Engineers Southern Illinois University Carbondale 5 5 2010 Nitrogen Cycle Wikipedia Commons Nitrogen Cycle svg Environmental Biology for Engineers Rock Cycle Environmental Biology for Engineers Images Videos References NASA Goddard Space Flight Center Water Cycle Water Cycle Graphics NASA Goddard Space Flight Center NASA Earth Observatory The Water Cycle Steve Graham Clair Parkinson and Mous Chahine http earthobservatory nasa gov Features Water water php NASA Earth Observatory The Carbon Cycle PhysicalGeography net Carbon Cycle Graphic Lightning strike Axel Rouvin Wikimedia Commons access May 2010 Nitrosomonas Internet Chemistry VisionLearning Earth Science http www visionlearning com Environmental Biology for Engineers http svs gsfc nasa gov vis a010000 a010400 a010498 index html Oxidation Reduction Nitrogen Fixation http library kcc hawaii edu external chemistry everyday nitrogen html http www visionlearning com Accessed May 2010 Carbon Cycle http www physicalgeography net fundamentals 9s html Vision Learning The Hydrologic Cycle Anne E Egger Stanford http earthobservatory nasa gov Features CarbonCycle carbon cycle php http svs gsfc nasa gov vis a010000 a010500 a010509 index html NASA Image by Yuichi Suwa TEM Technology Digital Learning center for Microbial Ecology http commtechlab msu edu sites dlc me zoo zdrs0232 html Nitrogen fixation on clover root The Microbial World The Nitrogen cycle and Nitrogen Fixation Jim