ENVI SCI LT 2 Notes PDF

Module 4 I. Energy Energy - The ability to bring about change or to do work - Two kinds of energy 1) Potential energy a) Store energy 2) Kinetic energy a) Energy possessed by a system by virtue of its motion Law of Thermodynamics - E...

Module 4 I. Energy Energy - The ability to bring about change or to do work - Two kinds of energy 1) Potential energy a) Store energy 2) Kinetic energy a) Energy possessed by a system by virtue of its motion Law of Thermodynamics - Energy cannot be created or destroyed but can be changed from one form to another - Energy is always conserved - All energy transformation is accompanied by the release of heat - Heat must be released, otherwise, the system’s temperature will increase and will eventually lead to the destruction of said system - When energy is transformed and heat is released, in a way, the quality of energy degrades which is line with the second law of thermodynamics - All processed in nature occur only with an increase in entropy and the direction of change always leads to an increase in entropy - entropy or disorder or randomness 1) 1st Law of Thermodynamics - Energy cannot be created or destroyed. 2) 2nd Law of Thermodynamics - For a spontaneous process, the entropy of the universe increases. 3) 3rd Law of Thermodynamics - A perfect crystal at zero Kelvin has zero entropy. History - Industrial revolution (18th to 19th century) - Use of oils and natural gas - Discover of coal as a source of energy - Household heating -> industrial purposes 1) Ancient Greece, 600 BCE (2,600 years ago) a) Thales of Miletus i) Ancient greek who was thought to be the first person to observe electrical phenomena ii) Discovered that when pieces of amber are rug with fur, they could pick up small pieces of straw iii) Amber was called “electron” in Thales’s language 2) London, England 1600 a) William Gilbert i) A 17th century English scientist  ii) Discovered that with a careful experimentation, a number of other materials could display the attractive properties of amber iii) Also found that they could attract objects besides straw iv) Named these amberlike objects after the greek for amber v) Called them “electrics” 3) Norwich, England 1646 a) Thomas Browne i) Carried out similar experiments ii) Described the experiment differently than William (1) When you rub a crystal with a cloth, it becomes an electric object which possesses the property of electricity 4) Paris, France 1736 a) Charles Du Fay i) 18th century French physicist ii) Found that almost any object except metals and fluids could be turned electric after subjecting them to a combination of heating and rubbing iii) When two electric are place near each other, thet sometimes attract or repel iv) Found there were two distinct groups of electric (1) Same group - repel (2) One from each group - attract 5) Philadelphia, Pennsylvania, 1748 a) Benjamin Franklin i) Learned how to make electrical devices that would de electrify by producing very large sparks ii) Electrifying and de electrifying - charging and discharging of weaponry iii) Link the objects together - cannons on a ship (1) Battery would discharge at the same time causing large sparks iv) He supposed that there is a substance called the electrical fluid that is common to all things (1) Rubbing the tube would cause a flow of fluid or an electrical current to move from the person to the glass in which both the person and the tube would become electrics as a result (2) Object with an excess of fluid was positively charged (3) Object lack of fluid is negatively charged (4) The bigger the difference in the fluid the larger the distance the fluid can jump causing sparks in the air (5) It is the material of the object that determines if it gains or loses electrical fluid during charge 6) Cambridge, England 1897 a) J.J Thomson i) Discovered that the electrical fluid is actually made up of small particles called electrons as named by physicist George Stoney  ii) It was discovered that the electrons flow to the opposite direction to what Franklin supposed iii) Objects that are positively charged dont have excess of electron fluid but actually lack electrons Electrons - Negatively charged particles - Can move easily around (sparks), especially if the electrons are loosely bound such as in metals and salt water Protons - Positively charged Neutrons - Have no charge Static electricity - Small park created the electrons quickly move to the positively charged object when the two objects come in contact (electrons tend to go where they are needed, nature always restores balance) A turbine generator set converts mechanical energy to electrical energy. In the case of natural gas, coal, nuclear fission, biomass, petroleum, geothermal, and solar thermal, the heat that is produced is used to create steam, which moves the blades of the turbine. In the cases of wind power and hydropower, turbine blades moved directly by flowing wind and water, respectively.solar photovoltaic panels convert sunlight directly to electricity using semiconductors Electricity - Most commonly used form of energy in human systems - Generated by converting kinetic energy to electrical energy - Usually involves a generator that has magnets and coils of metals such as copper and aluminum - metals in which electrons are loosely held  - Through a turbine for example, the magnet is moved around the coils of metal wire, and this pushes the electrons in the wire - When this happens, an electric current is created Non-renewable sources 1) Coal a) A readily combustible black of brownish-black sedimentary rock normally occurring in rock layers b) Most abundant fossil fuel c) Came from dead plants many years ago, especially plants that lived in swamps d) The dead plants cannot completely be decomposed by bacteria and fungi because of the lack of oxygen (especially in swampy areas) and through time, the plant material is buried under layers of sediments.  e) Peat i) A brownish substance in which the organic matter is initially converted ii) Various types of coal are formed depending on temperature and pressure applied to the peat (1) Lignite (2) Bituminous coal (3) Anthracite (a) The most ideal coal because of its high content and low sulfur content 2) Petroleum or crude oil a) Formed the same way as coal, but instead of plants, it is formed from large amounts of dead microscopic aquatic organisms b) A mixture of gaseous, liquid, and solid hydrocarbons c) A naturally occurring, flammable liquid found in rock formations in the Earth d) Means “rock oil” and originates from remains of planktons e) It can be refined to form different petroleum products i) Liquified petroleum gas ii) Gasoline iii) Aviation fuel iv) Heating oil v) Diesel vi) Asphalt vii) Oil (1) Can also be used to make plastics, paints, and even medicines f) Crude oil i) Mixture of hydrocarbons that formed from plants and animals that lived millions of years ago ii) A fossil fuel and it exists in liquid form underground reservoirs in tiny spaces within sedimentary rocks, and near the surface in tar (or oil) sands iii) After crude oil is removed from the ground, it is sent to a refinery where different parts of the crude oil are separated into useable petroleum products  (1) This petroleum products include gasoline, distillates such as diesel fuel and heating oil, jet fuel, petrochemical feedstocks, waxes, lubricating oils, and asphalt g) Petroleum products i) Fuels made from crude oil and other hydrocarbons contained in natural gas ii) Can also be made from coal, natural gas, and biomass iii) Include transportation fuels, fuel oils for heating and electricity generation, asphalt and road oil, and feedstocks for making the chemicals, plastics, and synthetic materials that are in nearly everything we use. 3) Natural gas a) A gas consisting primarily of methane b) The cleanest of all fossil fuels c) A relatively clean burning fossil fuels as it results in lesser emissions compared to coal or petroleum d) It is formed during the complex natural formation of oil e) Composed mainly of methane with other hydrocarbons such as propane and butane f) Pros i) Technology and infrastructure already exist g) Cons i) Contributes to heat and pollution ii) Difficult to extract iii) Environmental impacts iv) Expensive process  \ 4) Nuclear energy a) Nuclear fission (splitting b) Nuclear fusion (combination) c) Releases a large amount of energy d) Pros i) Energy content is large ii) Inexpensive to develop iii) No air and thermal pollution iv) Extraction is safe e) Cons i) Catastrophic ii) Poisonous and radioactive wastes iii) Connections with nuclear power and nuclear weapons iv) Limited resource Renewable Sources 1) Biofuel a) Fuel generated from the sugars of the plants b) Yeast fermentation to produce ethanol 2) Biomass f) Plant material and animal waste e g) Decomposing garbage produce methane 5) Geothermal a) Use of underground steam to run the turbines of a power plant 6) Hydropower a) The gravitational descent of a river is compressed from a long run to a single location with a dam 7) Solar power a) Using photovoltaic cells to convert sunlight into electricity 8) Wind power a) Uses the power of the wind to propel the blades of wind turbines 9) Tidal power a) Can be extracted from Moon-gravity powered tides b) Tides are caused by combined effects of gravitational forces exerted by the moon, the sun, and the rotation of the earth c) Tidal plants can only be installed along coast lines where 2 low tides and 2 high tides are experienced on a daily basis d) The difference in water levels must be at least 5 meters high to produce electricity e) Tidal electricity can be created from several technologies i) Tidal barrages (1) Most efficient tidal energy sources (2) A dam that utilizes the potential energy generated by the change of height between high and low tides (3) This energy turns the turbines or compresses air which in turn creates electricity ii) Tidal fences (1) Turbines that operate like giant turnstiles (2) Electricity is generated when mechanical energy of tidal currents turns turbines connected to a generator (3) The generator produces electricity  iii) Tidal turbines (1) Similar to wind turbines only underwater (2) Works like tidal fences f) Ocean currents generally generate electricity more than air currents because ocean water is 832 times more dense than air and therefore applies greater force on the turbines g) Easy to install and renewable, no direct greenhouse emission, and a low environmental impact h) Because the ocean’s tidal patterns are well understood, it is a predictable energy source making it highly attractive to electrical grid management which sets it apart renewables that can be more unpredictable i) Adoption of the technology has been slow and so far the amount of power generated using tidal power has been small which is due largely to the very specific site requirements necessary to produce tidal electricity j) Tide cycles also don’t match the daily consumption patterns of electricity which makes it insufficient to satisfy daily demands 10) Wave power a) Channels and directs the power of the wave to move turbines b) Wave star i) A facility designed to convert kinetic energy into electricity ii) Located in Denmark iii) It’s equipped with kinetic energy harvesters called floats iv) The floats move up and down with the kinetic motion of the waves v) The motion of the floats is transferred via hydraulics to rotate power generators vi) This facility enables continuous energy production and a smooth output vii) In the event of a storm the flotas can be lifted to a safe position viii) The facility could also be upgraded to utilize wind and solar power ix) The full scale device will be equipped with 20 floats of 10m (66ft) in diameter x) Each power station will be able to produce 6 megawatts of energy xi) Thus enabling a single machine to provide energy for 4,000 homes 11) Ocean thermal a) Uses the difference in temperature of the ocean to produce steam b) Ocean thermal energy conversion i) Natural differences of temperature in the ocean to produce electricity ii) Works best in tropical equatorial zone where temperature difference is at least 20 degrees celsius throughout the year c) How does it work i) The ocean’s warm surface water vaporizes a working fluid with a low boiling point like ammonia for example ii) The vapor expands and spins a turbine that is coupled to a generator that produces electricity iii) The vapor is then cooled by cold deep sea water  iv) That way, the working fluid condenses back into a liquid and you can reuse it v) This makes it a continuous electricity generating cycle d) By helping to develop offshore technology and and process equipment for OTEC, it can be an important renewable source Atmosphere - Nitrogen and oxygen are by far the most common - Dry air is composed about 78% nitrogen (N2) and about 21% oxygen (O2) - Argon, Carbon Dioxide (CO2) and many other gases are also present in much lower amounts - Each makes up less than 1% of the atmosphere’s mixture of gases - The atmosphere also includes water vapor Air pollution - A mix of particles and gases that can reach harmful concentrations both outside and indoors - Its effects can range from higher disease risk to rising temperatures - Soot, smoke, mold, pollen, methane, and carbon dioxide are just few examples of common pollutants - Come from natural and human sources 1) Natural sources a) Include dust blown by wind, pollutants from wildfires and volcanic eruptions, and volatile organic chemicals released by some plants b) Most natural air pollutants are spread out over the globs or remove by chemical cycles, precipitation, and gravity ‘ c) However, chemicals emitted from volcanic eruptions and some natural forest fires can reach harmful levels 2) Human sources a) Human inputs of outdoor air pollutants occur mostly in industrialized and urban areas where people, motor vehicles, and factories are concentrated b) Most of these pollutants enter the atmosphere from the burning of coal in power and industrial plants (stationary sources), and gasoline and diesel fuel in motor vehicles (mobile sources) - Classify outdoor pollutants in two categories 1) Primary pollutants a) Harmful chemicals emitted directly into the air from natural processes and human activities 2) Secondary pollutants a) Some primary pollutants may react with one another or with the basic components of air to form new harmful chemicals - Indoor air pollution - Considered by experts to be a higher-risk human health problem then outdoor air pollution - Some came from outdoors  - Chemicals used or produced inside buildings in developed areas can be dangerous pollutants, as can smoke from poorly designed wood or coal stoves used to provide heat and cook food in many developing countries - Poses a health risk that can and does harm life - Harms the human respiratory and pulmonary systems - Emphysema, asthma, and other respiratory illnesses may result from or be aggravated by chronic exposure to certain pollutants, such as O3 or particulates - Breathing polluted air slows lung development in children as much as having a parent who smokes tobacco - Teenagers who are chronically exposed to polluted air are five times as likely to have reduced lung function as are teens who breathe clean air - Children and adults with chronic exposure to elevated ozone levels are more likely to develop asthma - Breathing polluted air can also thicken human artery walls which is an important risk factor for heart failures and strokes - Indoor smoke is an ongoing health threat to the 3 billion people who can cook and heat their homes by burning biomass, kerosene, and coal - 15% of all deaths in the world are from ischemic heart disease; when your heart suffocates. Major air pollutants 1) Carbon monoxides (CO) Colorless, odorless, and highly toxic gas that forms, during the incomplete combustion of carbon-containing molecules Major sources are motor vehicle exhaust, clearing and burning of forests and grasslands, tobacco smoke, and cooking with open fires and inefficient stoves Reacts with hemoglobin in red blood cells and reduces the ability of blood to transport oxygen to body cells and tissues Chronic exposure can trigger heart attacks and aggravate lung diseases such as asthma and emphysema At high levels, causes headache, nausea, drowsiness, mental impairment, collapse, coma, and death 2) Carbon dioxide (CO2) A colorless, odorless gas 93% of the CO2 in the atmosphere is the result of the natural carbon cycle Rest comes from human activities, mostly burning fossil fuels and clearing forests and grasslands Emissions from human activities have been rising sharply since the industrial revolution Increasing levels of CO2 can contribute to warming of the atmosphere and global climate change 3) Nitrogen oxides Collective name for NO and NO2 Play a part in the formation of photochemical smog  i) A mix of chemicals formed under the influence of sunlight in cities with heavy traffic Nitrogen oxide (NO) ii) Colorless gas that forms when nitrogen and oxygen gas in air react at the high combustion temperatures in automobile engines and coal-burning power plants iii) Also produced by lightning and certain bacteria in soil and water as part of the nitrogen cycle Nitrogen dioxide (NO2) iv) A reddish brown gas v) Formed by NO reacting with oxygen in the air Nitric acid (HNO3) and nitrate salts (NO3) vi) Formed by the reaction of NO2 with water vapor in the air vii) Components of harmful acid deposition 4) Nitrous oxide (N2O) a) A greenhouse gas b) Emitted from fertilizers and animal wastes and is produced by burning fossil fuels c) Can irritate the eyes, nose, and throat, aggravate lung ailments such as asthma and bronchitis, suppress plant growth, and reduce visibility 5) Sulfur dioxide a) A colorless gas with an irritating odor b) About one-third of the SO2 in the atmosphere comes from natural sources as part of the sulfur cycle c) The other two-thirds (and as much as 90% in urban areas) come from human sources, mostly combustion of sulfur-containing coal in electric power and industrial plants and from oil refining and smelting of sulfide ores d) Can be converted to microscopic suspended droplets of sulfuric acid (H2SO4) and suspended particles of sulfate (SO4 +2) salts that return to the earth as a component of acid deposition e) These pollutants also reduce visibility and aggravate breathing problems f) SO2 and H2SO4 can damage crops, trees, soils, and aquatic life in lakes g) Can corrode metals and damage paint, paper, leather, and stone on building sand statues 6) Particulates a) Suspended particulate matter (SPM) b) Consists of a variety of solid particles and liquid droplets small and light enough to remain suspended in the air for long periods c) About 62% of SPM in outdoor air comes from human sources such as dust, wild fires, and sea salt d) The remaining 38% comes from human sources such as plowed fields, road construction, unpaved roads, tobacco smoke, coal-burning electric power and industrial plants, and motor vehicles e) Can irritate the nose and throat, damage the lungs, aggravate asthma and bronchitis, and shorten life f) Toxic particulates i) Lead, cadmium, and PCBs ii) Can cause mutations, reproductive problems, and cancer iii) Mostly from burning coal and leaded gasoline and smelting lead ores iv) Can accumulate in the body and cause nervous system damage, mental retardation (especially in children), and digestive and other health problems 7) Ozone (O3) a) A colorless and highly reactive gas b) A major component of photochemical smog c) Can cause coughing and breathing problems, aggravate lung and heart diseases, reduce resistance to colds and pneumonia, and irritate the eyes, nose, and throat d) Damages plants, rubber in tires, fabrics, and paints 8) Volatile Organic Compounds (VOCs) a) Organic compounds that exist as gases in the atmosphere b) Most are hydrocarbons such as isoprene (C3H8) and terpenes C10H15 emitted by the leaves of many plants, and methane CH4, a greenhouse gas c) About a third of global methane emissions come from natural sources, mostly plants, wetlands, and termites  d) The rest comes from human sources such primarily rice paddies, landfills, and oil and natural gas wells and from cows (belching and flatulence) e) Other VOCs, including benzene, vinyl chloride, and trichloroethylene (TCE) are used as industrial solvents, dry-cleaning fluids, and components of gasoline, plastics, drugs, synthetic rubber, and other products There’s a 30% drop in air polluted nitrogen dioxide - formed from the burning of fossil fuels (like burning in car engines or electricity) during the pandemic Carbon dioxide peaked during the industrial revolution We’ve been burning fossil fuels like oil and coal which release CO2 to power homes factories Population tripled We consumed more products from animals that release another pollutant called methane When sunlight gets into the earth’s atmosphere, some of the heat gets trapped and the planet gets warmer which is why they call it the greenhouse effect The concern is not the earth is getting warmer but it’s happening far too quickly Paris Agreement - World leaders sign this in 2016 - The big pledge is to cap temperatures rising by 1.5 degrees or a maximum of 2 before the year 2100 - Countries set their own targets on how much CO2 they emit - US, one of the world’s biggest polluters pulled out of the Paris deal - Russia and China are accused of not giving themselves ambitious targets in the first place  - Turkey and poland want to build more power plants that use coal - India, Morocco, and Gambia have massive renewable energy projects Hydrosphere Water - Only 1% of the world’s water is accessible for human consumption - Only 2.5 of the world is freshwater - 68.1% is ice - 30% is groundwater - 1.2% is surface water namely rivers, lakes, ground moisture, permafrost and water present in the atmosphere - Most liquid freshwater is actually hidden underground and can be found in most unexpected places - Who uses the water and how is it managed? 1) Domestic 11% 2) Industry 19% a) 90% of all electricity generations water intensive 3) Agriculture 70% Blue water and green water - Refer to the water used by agriculture Green water - When rain falls over a field, some of the water get stored in the upper soil as moisture - Accounts for most of the water used in agriculture Blue water - Makes up all surface water such as rivers, lakes, as well as groundwater - These resources are exploited for irrigation when droughts occur and rainfall is scarce - Often these irrigation techniques are not efficient and can easily deplete aquifers rivers and lakes Virtual water - 90% of our water consumption is invisible to us Ground water - Can act as a recharge to rivers when the water table intersects the stream - In the same way the river can act as a recharge for groundwater - Withdrawal of groundwater by pumping from wells can reduce streamflow, lower lake level, and reduce water in wetlands - Groundwater management requires that the linkages between surface water and groundwater be known and understood - When groundwater becomes contaminated, it cannot cleanse itself of degradable wastes as flowing surface water does for several reasons 1) It flows so slowly 2) Lowe concentrations of dissolved oxygen  3) Smaller populations of decomposing bacteria 4) Cold temperatures slow down chemical reactions that decompose wastes - Permanent pollutants - Non Degradable wastes such as toxic lead, arsenic, and fluoride - Some ways to remediate groundwater pollution are as follows 1) Extraction wells a) Pumping out contaminated water and treatment by filtration, oxidation, air stripping (volatilization of contaminant in an air column) or biological processes 2) Vapor extraction a) Use of vapor-extraction well and then treatment 3) Bioremediation a) Injection of nutrients and oxygen to encourage growth of organisms that degrade that contaminant in the groundwater 4) Permeable treatment bed a) Use of contact treatment as contaminated water plume moves through a treatment bed in the path of groundwater movement; neutralization of the contaminant by chemical, physical, or biological processes Hydrologic cycle  - The movement of water in the seam in the air and on land, which is driven by solar energy and gravity - This irreplaceable water recycling and purification system works well, unless we overload it with slowly degradable and non-degradable wastes, withdraw water from underground supplies faster than it is replenished, or destroy wetlands and cut down forests that store and slowly release water Groundwater - One of our most important sources of freshwater - Some precipitation infilitrates the ground and percolates downward through spaces in soil, gravel, and roc - Normally moves from points of high elevation and pressure to points of lower elevation and pressure Zone of saturation - Below a certain depth - These spaces are completely filled with water Water table - Top of the groundwater zone - Falls in dry weather, or when we remove groundwater faster than nature can replenish it, and it rises in wet weather - Depth of water in the well directly correlate with the water table Aquifers - Geological layers deeper down - Underground caverns or porous layers of sand, gravel, or bedrock through which groundwater flows - Watertight layers of rock or clay below scuch aquifers keep the water from escaping deeper into the earth  - Most aquifers are replenished naturally by precipitation that percolates downward through soil and rock, a process called natural recharge - Most aquifers recharge extremely slowly - Two types depending on whether or not the aquifer is confined an impermeable layer 1) Confined a) Confining units i) Low hydraulic conductivity (1) Measure of rock’s ability to transmit water (2) E.g. shales - they don’t transmit water very well especially compared to sandstone ii) Well is built which pushes the water into the surface because of the pressure inside 2) Unconfined a) E,g. Sandstones i) Can transmit water fairly decently ] b) None of the water in the unconfined aquifer can transmit in the confined aquifer c) There’s not much pressure built in that area Elevation head - Body water from precipitation is moved down in the confined aquifer by gravity Pressure head - Body of water is moved into a confined unit which is under pressure since there is no elevation Flowing artesian well - Well inside of a confined aquifer and that pressure forces the water up above the surface Potentiometric surface - Where the water wouldnt flow to if you were to puncture that confined aquifer and let the water flow up as a result of the pressure built up within the confined aquifer - A pressure measurement within that aquifer Watersheds - Flow of water on land is divided into watersheds - An area of land that contributes water to a particular stream or river Drainage basin - Basic unit of the landscape Drainage divide - The boundary between the drainage basin Point sources - Discharge pollutants at specific locations through drain pipes, ditches, or sewer lines into bodies of water - Examples include factories, sewage treatment plants (which remove some but not all pollutants), underground mines, and oil tankers - Located at specific places, they are fairly easy to identify, monitor, and regulate - Most developed countries have laws that help control point source discharges of harmful chemicals into aquatic systems - In most developing countries, there is little control of such discharges Nonpoint sources - Scattered and diffuse and cannot be traced to any single site of discharge - Examples include runoff chemicals and sediments into surface water from cropland, livestock feedlots, logged forests, urban streets, lawns, and golf courses - We have made little progress in controlling water pollution from nonpoint sources because of the difficulty and expense of identifying and controlling discharges from so many diffuse sources Rivers and streams - Can recover rapidly from pollution caused by moderate levels of degradable, oxygen demanding wastes and excess heat - They do so through a combination of dilution, biodegradation, and the presence of bacteria that break down the waste - This natural recovery process does not work when streams become overloaded with pollutants or when drought, damming, or water diversion reduce their flows - These processes do not eliminate slowly degradable or non-degradable pollutants - -  - Dilution of pollutants often is less effective in lakes and reservoirs than in streams for two reasons 1) Lakes and reservoirs contain stratified layers that undergo little vertical mixing 2) They have little flow a) The flushing and changing of water in lakes and large artificial reservoirs can take from 1 to 100 years, compared with several days to several weeks for streams b) As a result, lakes and reservoirs are more vulnerable than streams are to contamination by runoff or discharge of sediments, plant nutrients, oil, pesticides, and toxic substances such as lead, mercury, and selenium. i) These contaminants can kill bottom mlife and fish and birds that feed on contaminated aquatic organisms ii) Many toxic chemicals and acids also enter lakes and reservoirs from the atmosphere What are the sources of water pollution? 1) Oxygen demanding waste a) Dead plant and animal watter, called organic matter, in streams decays over time; that is, it is consumed by bacteria, which require oxygen b) Aerobic bacteria - require oxygen to live c) If there is enough bacterial activity, the oxygen in the water can be reduced to levels so low that fish and other organisms die d) The amount of oxygen used for bacterial decomposition is i) Biochemical oxygen demand (BOD) (1) A commonly used measure in water-quality management (2) High BOD indicates a high level of decaying organic matter in the water 2) Pathogenic organisms a) Those that can be seen only with a microscope b) Important biological pollutants c) Cause cholera, typhoid infections, hepatitis, and dysentery which are all water borne diseases  d) Difficult to monitor so the level of human fecal coliform bacteria is used as a common measure of biological pollution and as a standard measure of microbial pollution e) Fecal coliform bacteria i) Usually harmless ii) Part of the normal constituents of human intestines iii) Found in all human waste 3) Nutrients a) Nutrients released by human activity may lead to water pollution b) Two important nutrients can cause problems i) Phosphorus and nitrogen (1) Released from a variety of materials, including fertilizers detergents, and the products of sewage treatment plants (2) Concentration of P and N in streams is related to land use (3) Forested land has the lowest concentrations of phosphorus and nitrogen (4) Highest concentrations are found in agricultural areas, such as fertilized farm fields and feedlots (5) Urban areas can also add and phosphorus and nitrogen to local waters, particularly where wastewater-treatment plants discharge treated waters into rivers, lakes, or the ocean (a) Effective in reducing organic pollutants and pathogens (b) Without advance treatment, nutrients pass through the system (6) High human-caused concentrations in water often result in the process known as cultural eutrophication (a) Excess fertilizers are put by the farmers in which excess nutrients are carried by the rain and other forms of irrigation which mix into water and find ways into bodies of water (b) Algae, phytoplankton, and plants grow excessively called algal bloom because of the excess nutrients that went into bodies of water (c) Floating layers of algae form impenetrable roof on the water not allowing sunlight through the bottom of the lake (d) All plants below the surface cannot partake in photosynthesis (e) The problem is when all the nutrients are used up and the water cannot support life; thus they die off and sink to the bottom of the water (f) Decomposers decay the dead bodies and consume oxygen  (g) All the oxygen are used for decomposition and none are left for other living organisms because of the peak of dead bodies (h) This creates a cycle: die off -> decomposition -> low oxygen content -> die off (i) In lakes, native species can be suppressed allowing invasive spacies (j) In oceans, corals bleach and may die (k) Lower biodiversity in mini ecosystems ii) Oil (1) Largest oil discharges have usually involved oil-tanker accidents iii) Toxic substances (1) Many substances (heavy metals, synthetic organic chemicals, etc) that enter surface water and groundwater are toxic to organusns iv) Others (sediments thermal pollution, etc) Acute watery diarrhoea - One of the top 10 leading causes of death in the Philippines which could worsen during El Nino phenomenon and climate change that can dry up water sources Geosphere - Includes rocks and minerals on Earth - Also includes the abiotic parts of soils, and the skeletons of animals that may become fossilized over geologic time - About processes of the rock cycle such as metamorphism, melting and solidification, weathering, erosion, deposition, and burial - Responsible for a constant recycling of rocks on Earth between sedimentary, igneous, and metamorphic rocks 1) Sedimentary rocks a) Formed via weathering and transport of existing rocks, and then deposition, cementation, and compaction into a sedimentary rock 2) Igneous rocks a) Formed by cooling and crystallization of molten rock 3) Metamorphic rocks a) Formed when heat or pressure are applied to other rocks Tectonic plates - Primary agent driving geological processes - Creates mountains, volcanoes, and ocean basins Soil - Solid Earth material that has been altered by physical, chemical, and biological processes such that it can support rooted plant life, according to scientists - Products of disintegration or decomposition of rocks according to geologists Texture of the soil - Depends upon the relative proportions of sand, silt, and clay-sized particles 1) Clay particles a) Have a diameter of less than 0.004 mm (0.0002 in) b) Grains cannot be seen with such a hand lens c) Cohesive d) Cannot be easily dusted off when mixed with water, smeared on the back of the hand, and allowed to dry e) Tiny particle size and plate-like structure i) Holds water and nutrients effectively f) Composed of different minerals than sand and silt g) More like a stack of paper plates than a grain of sand 2) Silt particles a) Have diameters ranging from 0.004 to 0.063 mm (0.0002 to 0.003 in) b) Grains can be seen with a 10x hand lens c) Feels like baking flour d) Can be easily dusted off when mixed with water, smeared on the back of the hand, and allowed to dry 3) Sand particles  a) 0.063 to 2.0 mm (0.003 to 0.08 in) in diameter b) Individual grains are seen c) Gritty and crunches between the teeth d) Can be easily dusted off when mixed with water, smeared on the back of the hand, and allowed to dry e) Has a large chunky structure which does not hold water and nutrients effectively 4) Earth materials with particles larger than 2.0 mm (0.08 in) in diameter depending on the particle size a) Gravel b) Cobbles c) Boulders - Commonly identified by estimation and then refined in a laboratory by separating and determining the proportions of the sand, silt, and clay Amount of surface area available in sand - Related to a soil particle’s ability to react with water and nutrients - When the individual particle size is small, more individual particles will fit in a given space, and thus making more surface area available Soil color - An indicator of organic matter content, drainage, and aeration - Has little effect on plant growth but an indicator of soil properties that do not affect plant development 1) Black a) High in organic matter (4 percent or more) 2) Brown a) Good organic matter content and well drained 3) Red a) Low in organic matter, well drained b) Due to the presence of iron (often ferric oxide, Fe2O3) 4) Gray a) Low in organic matter, poorly drained b) Due to an excess of water and poor aeration c) Due to the presence of iron (often ferrous oxide FeO) 5) Yellow a) Low in organic matter, well drained 6) Mottling effects in subsoil a) Indicates both well and poorly drained conditions during the year due to fluctuations in water table Essential nutrients for plant growth - 17 elements - 14 come from the soil - If there is deficiency of any essential element, plants cannot complete their vegetative or reproductive cycles - Some of these nutrients combine to form compounds that make up cells and enzymes  - Other nutrients are necessary for certain chemical processes to occur Nitrogen - Building block of plant proteins - Integral part of chlorophyll - A component of amino acids, nucleic acids, and coenzymes - Most nitrogen in the soil is tied up in organic matter - Taken up by plants as nitrate (NO3-) and ammonium (NH4+) ions from inorganic nitrate and ammonium compounds - These compounds can enter the soil as a result of bacterial action (nitrogen fixation), application or inorganic nitrogen fertilizer, or conversion of organic matter into ammonium and nitrate compound Phosphorus - Plants use to form the nucleic acids DNA and RNA - To store and transfer energy - Promotes early plant growth and root formation through its role in the division and organization of cells - Essential to flowering and fruiting and to the transfer of hereditary traits - Absorbed by plants as H2PO4-, HPO4-2, or PO-3 depending upon soil pH - The mobility of phosphorus in soil is low, and deficiencies are common in cool, wet soils Potassium - Necessary to plants for translocation of sugars and for starch formation - Important for efficient use of water through its role in opening and closing small apertures (stomata) on the surface of leaves - Plants take up potassium in the form of potassium ions - Relatively immobile in soils but can leach in sandy soils Traditional agriculture - Involves plowing the soil in straight lines, or furrows - Particularly damaging - Removal of vegetation exposes the soil to erosion by wind and water Key to sustaining soil resources - To reduce erosion to a rate less than the rate at which soils naturally form - Some practices to sustain soils include 1) Contour plowing a) Involves plowing with the natural topography of the land b) Furrows are plowed perpendicular to the slope of the land rather than in the downslope direction c) One of the most effective ways to reduce erosion by running water and is widely used 2) No-till agriculture a) This system eliminates plowing altogether, greatly reducing soil erosion b) An integrated plan to plant and harvest crops without plowing while suppressing weeds and other pests 3) Terracing slopes a) Soil erosion on steep slopes can be managed and minimized by terracing slopes to produce flat areas for farming b) Retaining walls of stone or other materials are used to form terraces and stabilize the slope c) Widely used on farms around the world 4) Planting of more than one crop a) Most effective on small farms in the tropical rain forest and other areas b) Forest trees are cut in small patches of land, and some smaller trees and plants are left in place c) Several crops are planted among the remaining natural vegetation d) After several years, the land is allowed to recover e) When the forest has grown back, the process may be repeated f) Works if human population on the land is low  g) With increased population and pressure to farm more land more frequently, the practice is not sustainable Soil erosion problem in the Philippines - Quite pronounced with more than half of the country’s land area having a slope exceeding eight percent - Aggravated by heavy rainfall, improper land use and management, excessive and improper logging, shifting cultivation and road construction Prime agricultural lands - Located around the main urban and high population density areas