Environment

INTRODUCTION TO ENVIRONMENTAL STUDIESINSTRUCTOR Bhola R. Gurjar, Ph. D.ProfessorDepartment of Civil EngineeringOffice: Room # 307

E-mail: brgurjar@gmail.com

CE-105, Introduction to Environmental Studies; L: 3; Credits: 3; S. No.ContentsContact Hours1.Overview: Environment and Natural Processes; Development (Resource Utilization & Waste Generation); Environmental issues; Concept of Sustainable Development; Issues affecting future development (population, urbanization, health, water scarcity, energy, climate, toxic chemicals, finite resources etc.); Environmental units 62.Air Water interaction: (Liquid phase-gas phase equilibrium) Henrys Law Constant with units, Dimensionless Henrys Law Constant 33.Water Soil Interaction: Carbonate System (Alkalinity and buffering capacity); Major ions in water; Natural Organic Matter (NOMs); Water quality parameters; Physical processes (Mass Balance): Spatio-temporal variation in quality of river water, lake water, ground water; Water quality standards 94.Water treatment and wastewater treatment .45.Air resources: Atmosphere; Air pollutants; Emissions and control of air pollutants; Transport of air (global, regional, local); Air stability; Plume shape; Air Pollution: Meteorology and dispersion modeling; Air quality standards96.Land pollution and solid waste management, Wetlands, 3+27.Ecosystem: Structure and function; Energy flow in ecosystem; Material flow in ecosystem; Biodiversity and ecosystem health; Bio-amplification and bio-magnification 38.Hazardous Waste: Definition; Classification; Storage and management; Site remediation; Environmental Risk: perception, assessment, and management 3CE-105, Introduction to Environmental Studies; L: 3; Credits: 3; Objective: To introduce fundamentals of environmental pollution and its controlS. No.Name of Books / Authors/ PublishersYear of Publication/1Davis M. L. and Cornwell D. A., Introduction to Environmental Engineering, McGraw Hill, New York 4/e 20082Masters G. M., Introduction to Environmental Engineering and Science, Prentice Hall of India, New Delhi. 2/e 20073Peavy H. S., Rowe D.R. and Tchobanoglous G., Environmental Engineering, McGraw Hill, New York 19864.Mines R.O. and Lackey L.W. Introduction to Environmental Engineering, Prentice Hall, New York20095.Mihelcic J. R. and Zimmerman J.B. Environmental Engineering; Fundamentals, Sustainability, Design John Wiley and Sons, Inc2010

WHY IS THIS COURSE? WHY STUDY THE ENVIRONMENT?

More than 20 million computers are thrown out every year world wide, very few are recycledMore than 200 million computers shall be obsolete world wide within a next few yearsSame is true for many other electronic goods.Cell phones are getting obsolete every other month.

Humanitys Top Ten Problems

ENERGYWATERFOODENVIRONMENT POVERTYDISEASEEDUCATIONDEMOCRACYPOPULATIONTERRORISM & WAR

2011 7.0 Billion People2050 ~ 10 Billion People8RICHARD SMALLEY, NOBEL PRIZE (CHEMISTRY) WINNER 1996:

What to do with such a huge amount of e-waste?Problems with Electronic IndustryDesigners are not responsible for end of life designProduct manufacturing does not consider the entire life time of the productDesigners are not responsible for end of life designResult is waste economically inefficient, environmentally harmful, socially irresponsibleUNSUSTAINABLE

Each time a Google search is generated at the users computer, the carbon dioxide footprint is 0.2 g of CO2 per search.

http://www.guardian.co.uk/environment/2010/aug/12/carbon-footprint-internetAbout 1.2% of total fossil-fuel based carbon emission

Greenhouse gases. Global Warming.. Polar Ice caps melt. Sea level rises.. Many islands and countries shall get wiped out..

The Earth is finite..So are the natural resources..

SHORTAGE OF FRESHWATERIndia is destined to face critical stress on drinking water by the year 2025 along with 48 other countries. 31 of them are already water stressed.By the year 2050 about 4 billion people shall be seriously affected by water shortage around the globe. RESULT CONFLICT20

Environmental StudiesTo logically understand is Science &to channelize nature to improve standard of living is EngineeringThe motto is'Replenish the earth and subdue it'. Is there a barren desertirrigate it; is there a mountain barrierpierce it; is there a rushing torrentharness it. Bridge the rivers; sail the seas; and many more----Rossiter W. Raymond1913

Human (Our) actions have widespread impacts on our world and the other organisms with which we share it.

Science & technology: explain how things work & reveal how we can make our environment safer, more comfortable and more enduring.

Sailor, soldier, engineer, lawyer, orator, editor, novelist, story-teller, poet, biblical critic, theologian, teacher, chess-player22 Environmental StudiesEnvironmental Management: Prevention & ControlDevelopers (Engineers) can prevent environmental degradation by knowing the response of the environmentThink globally act locally

Environmental Scientists & Engineers can attempt to control the environmental degradation

A co-ordination between developmental projects , its environmental impacts and remedy is possible only when we are aware of our ENVIRONMENT, ENVIRONMENTAL SYSTEMS & ENVIRONMNTAL PROCESSES Sailor, soldier, engineer, lawyer, orator, editor, novelist, story-teller, poet, biblical critic, theologian, teacher, chess-player23Development & its Unintended ConsequencesWhat is Development? Resource utilization to provide facilities and services. Waste generation is the unintended consequence of developmentUnintended Consequences or Side EffectsResource depletionPollution/Environmental degradationWhat are we giving back to surrounding?Air: we cannot take inWater (wastewater): we cannot useScrap: we dislike

24Sustainable DevelopmentHow does environment respond to development?

How can development be made environment friendly?

Answer is to understand/study the project, environment, and environmental science, andTo work towards Sustainable Development

25Sustainable DevelopmentMeeting the needs of the present without compromising the ability of future generations to meet their own needs (WHO)

Design of human and industrial systems (Engineering) to ensure that humankinds use of natural resources do not lead to diminished quality of life due either to losses in future economic opportunities or to adverse impacts on social conditions, human health, and the environment. (Michelcic etal.,2003, Sustainability Science and Engineering: Emergence of a new Metadiscipline. Environmental Science & Technology 37 (23): 5314-5324)

Natural resources of the earth including air, water, land, flora and fauna and especially representative samples of natural ecosystems must be safeguarded for the benefit of present and future generations through careful planning and management.26SUSTAINABLE DEVELOPMENTAgreed Definition:Brundtland: meeting the needs of the present without compromising the ability of future generations to meet their own needs.

Need to balance three components: Economic, Social and Environmental Aspects

What is Environment?Biotic & Abiotic ComponentsInteractions/ProcessesAir-waterAir-SoilSoil-WaterAir-Water-SoilInteraction of life with air, water, soil Structural & Functional Components of the EcosystemNatural System connects and supports all life on Earth by providing Oxygen, Water, FoodServicesElemental and chemical composition of the earth together with energy from the sun, constitutes all of the raw material that support life.

airlandwaterlifeAtmosphere;Gas PhaseHydrosphereAqueous PhaseLithosphereSolid PhaseBiosphere29Environmental Systems (Natural and Engineered)Natural Systems:Concern is with understanding and describing changes in constituent concentrations and other quality parameters;Measure given conditions and describeanticipated changes in constituent(s)(Output depends on prevailing conditions)Engineered System:Concern is with the selection of conditions required to effectively accomplish specific changes in concentration and quality parametersDetermine desired changes in constituent and prescribe required conditions(Conditions are modified to get desired output)DescribeDesign30Environmental Processes (Natural & Engineered Processes)Environmental processes of interest are of two categories: Transformation ProcessesEnvironment is comprised of chemicals & transformation in them are described by chemical reactions Reactions are physical, chemical and/or biological in nature. Three dominant characteristics of environmental processes are:The form and amount of energy available to make them occurThe speed or rate at which energy is exercised to effect change. Most of the environmental reactions follow fist order kineticsA system of such spatial and physical characteristics that it allows reactants to interact or communicate for purposes of reactions.2. Transport ProcessesMacroscale Transport (System Scale):Movement of constituents in the bulk of a system & across its boundaries Microscale Transport (Molecular Scale): Small scale diffusion processesOccur primarily at the interfacesTransport from one phase to another is referred to as mass transferEnvironmental Processes (Natural & Engineered Processes)ProcessNatureExample/Mass TransferAbsorption by liquids (gas/liquid mass transfer)Dissolution air (oxygen, nitrogen, carbon-di-oxide) in Rivers, Lakes; Molecular diffusion of O2 across air-water interfaceAbsorption by solids Phase Transfer(liquid-solid)Absorption of organic contaminants from ground waters by soils & sediments; Interfacial & interparticle diffusion of solutesBiochemical TransformationOxidation-reductionBiochemical oxidation/reduction of organics in receiving water (BOD exertion); Diffusion & Metabolic products across cell wallChemical TransformationPhotochemical , acid-base reactionsAtmospheric reactions;Rain water soil-reactionsChemical PrecipitationPhase Transfer(liquid-solid)Iron oxide deposition at wetted interface, deposition of calcium carbonates & magnesium silicates on submerged surfaces; Interfacial & interparticle diffusion & particle growth DisinfectionInactivation of organisms by heat & sunlight; Mass or heat transfer across cell membranesFiltrationSeparation ProcessDeposition of bacteria & turbidity in subsurface system; Microscopipic particle transport & interfacial depositionIon ExchangeSeparation ProcessPhase TransferMultivalent cation uptake and retardation by soils; Interfacial & interparticle ion diffusion for porous ion exchange resinsVolatilizationPhase Transfer (liquid-gas)

Release of H2S from benthic deposits; Molecular diffusion of O2 across water-air interfaceEnvironmental Processes (Natural & Engineered Processes)Objectives, Information requirements, & expected results for natural & engineered systems are quite different;

The underlying processes & principles of change are essentially the same;33Environmental Systems (Measurement of Quantity and Concentration)Extensive Properties:Magnitude depends on the size of the system or on sample taken from the system (e.g. mass, volume, heat capacity and calories). Quantity is an extensive propertyIntensive property: Magnitude does not depend on the size of a system or on sample taken from it (e.g. temperature, density, specific heat etc.)Concentration is an intensive propertyExpression of concentration:mass fraction (0-1; % (per cent); (per mil); ppm; ppb) , volume fraction, mole fraction, mass per unit volume, moles per unit volume (molar), moles per unit mass (molal), equivalents (normal)Partial Pressure: Species amount in air may be expressed as partial pressurePx = -log [x]; [x] is molar concentration; pH, pOH, pCa++

3434Environmental measurement1. Ten gram of table salt (NaCl) in pure water is dissolved to make 1 L of solution. Determine for Na+ : the mass fraction (%, ppm), mass concentration, molarity, molality, normality, mole fraction in the solution. (Na = 23; Cl = 35.5)Molecular weight of NaCl = 23 + 35.5 = 58.510 g NaCl = 10/58.5 = 0.17 mole; Na+= 0.17 mole x 23 g/mole = 3.9 g of Na+.Mass fraction = 3.9/10 =0.39 % = 0.0039*106 = 3900 ppmMass concentration = 3.9 g/L = 3900 mg/L ( in aq. systems, mg/L = ppm)Molarity =0.17 mole/L or 0.17 M; Normality = 0.17 eq/L = 0.17 NMolality = 0.17 mole/ 0.99 kg = 0.172Mole fraction = 0.17/ (0.17 + (990/18) = 3.08 x 10-3Mole fraction of aqueous glucose solution is 0.025. What is the molar & mass concentration of glucose? (Assumption: density of the solution = 1) Moles of glucose = 0.025 = 0.25 x 180 = 4.5 g & moles of water = 0.975 = 0.75 x 18 = 17.55 gmolar concentration = (.025/ 17.55) x 1000 = 1.42 Mmass concentration = (4.5 g/17.55) x 1000 = 256.4 g/LRICHARD SMALLEY, NOBEL PRIZE WINNER 1996:

TOP 10 PROBLEMS OF HUMANITYSINGLE MOST IMPORTANT FACTOR DETERMINING THE PROSPERITY OF A HUMAN SOCIETYOut of 7 billion people worldwide only 1.5 billion enjoy modern quality energy Bringing rest of the people up in the economic ladder of human civilization, requires abundant, low-cost, clean energy

2011 7.0 Billion People2050 ~ 10 Billion PeopleImportance of energyEnergy is the currency of Civilization

Energy can neither be created nor destroyed (first law of thermodynamics). It may change forms in any given process.

Energy use is directly related to the development

Development is important for all countries and hence energy needs are ever increasing a big challenge

Most widely used energy sources include: Coal, oil, natural gas, hydropower, nuclear and fast developing source Biomass

Energy use is strongly related to environmental pollution

EnergySteam Engine (late 1700s): Machinery movement through pressurized steam; Steam Engines were the power source forSteamships, steam shovels, steam tractors, steam locomotives, stationary engines to run sawmills, textile mills & other plantsFossil fuels (coal, oil, natural gas) for steam generationFirewood (late 1700s)Coal (late 1800s): problems with use of coal -smoke, fumes, ash, hazardous to mine coal, Heavy machineryOil (Three major technologies developed in late 1800s: oil well drilling, internal combustion engine, refinement of crude into gasoline) -- Replacement of steam powered engines and furnaces with petroleum fueled engines and oil furnace (light machinery)By 1951 crude oil became dominant source of energyNatural Gas: Clean fuel

Global Primary Energy SupplyRenewable and non renewable sources of energyNon-renewable energy sources- finite resource: Natural gas - trapped as methane, crude oil - representing residual sludge. Coal - highly compressed organic matter, mostly leafy material from swamp vegetation-that decomposed relatively little. It takes 1000 years to accumulate the amount of organic matter that world would consume in one day).Renewable Energy Sources:Solar photovoltaic & thermalWindHydropowerOcean energyGeothermalWaste to energyBiomass derived fuel

Open & Closed Systems(Energy crossing boundary as heat & work)+ (energy of massentering the system)-(energy of mass leaving the system)=(net change of energy in the system)(Energy crossing boundary as heat & work)=(net change of energy in the system = mc T)*

Open & closed systemsOpen System: Energy & matter can flow across the boundary

Closed System: Only energy (E) flows across the boundary

Energy brings about microscopic (molecular energy) and macroscopic (Kinetic & potential energy) changes in the substances/systems

Power: rate at which energy is generated or used (energy per unit time).

Energy units: Specific Heat, kilocalorie (kcal), kilojoules (kJ)1 kcal/kg 0C = 1 Btu/lb 0F = 4.184 kJ/kg 0C =4184 J/kg-CW = J/s; kJ/s = kWkWh = (3600s) (kW) =3600 kwatt seconds=3600 s (kJ/s) =3600 kJ= 3.6 X106 joules1 kWh = 3.6 X106 joules = 3.6 X106 /4184 =860 kcal

Mass and energy balance for coal fired power plantIf coal usage in a power plant is 0.7 kg/kWh, what is the calorific value of coal? Consider that the power plant runs at 35% efficiency.

1 kWh = 3600 kJ = 860 kCal Actual calorific value of coal is= 5142 kJ/kg/0.35= 14690 kJ/kg = 14.7 MJ/kgCalorific value of coal if 100% of coal is converted to electrical energy= 3600 kJ/0.7kg = 5142 kJ/kgThe efficiency is 35%This means that only 35% of the calorific value of coal is converted to electrical energy----cont.Example: A 5 kW heater is used to raise the temperature of 150 L of water from 10 to 600C. Find out time required. (Assumptions: all of the electrical energy is converted to heat, energy is not required to raise the temperature of the tank, and no heat loss from the tank to the environment). Solution:rate of energy input; power = 5kWTotal Energy required = 5 x hr = 5 t kW hrEnergy output = 0Change in energy stored = m c T = 150 kg x 1 (kcal/kg -0C) x 500C = 7500 kcal5 t kW hr = 5 t hr x 3600 kJ/hr = 18000 kJ x t = 4285.7 kcal/hr x t = 7500 kcalt = 7500/4285.7 = 1.75 hr(Through such energy balance change in temperature of surrounding air /water can be calculated)

Electricity: Electrical Power-Secondary Energy Source (depends on primary source )

Electrical power is indispensable>33% of fossil fuel production is used to generate electricityGenerally it takes three units of primary energy to create one unit of electrical energy that actually is put to use, remaining two units are lost as heatCooling towers are integral part of thermal & nuclear power plants.Electric Generators: Mechanical energy is converted to electrical energyTurbo generators: Turbine coupled with generators Pressurized steam driven turbine (thermal power, non-renewable)Water driven turbines (hydro power, renewable)Wind turbines (Wind Power)Gas driven turbines(coal, oil, and nuclear energy are commonly used to generate steam. However, burning refuse, solar energy, and geothermal energy may be widely used in future).

45Thermal Power plants in IndiaCoal as a source of energy contains mixture of compounds of C and H, also contain appreciable amounts of O, N, S and mineral matter Indian coals are mainly bituminous / lignite & ash content is very high Coals typically have high ash content (ranging from 3550%), high moisture content (420%), low sulfur content (0.20.7%), and low calorific values (between 25005000 kcal/kg, which is much less than the normal range of 5000 to 8000 kcal/kg. Power plants in India use different qualities of coal, different combustion technologies and operating conditions.Ash generation from Indian coal is 132t/h as compared 17 t/h from International standardAccording to the Central Electricity Authority (CEA, 2010) the present (as on March, 2010) capacity for electricity generation from coal and lignite-based thermal power plants in India is 93772 MW.

48Emissions per unit of electricity during 2001-02 to 2009-10 Emissionsg/kWhAverage annual rate of increase %CO282 0 10005.6SO26.94-7.20*NO4.22-4.385.6Particulate matter (C)0.15 -0.17-Coal usage 0.7 0.78 kg /kWh; from 86 plantsKg emissions/kWh = (kg/vol.) x (volume of emission/kWh)* SO2 emission depends on S content in the coal(