CHEMLEC_FINALS PDF

Module 5: Nuclear Chemistry Two Categories of Isotopes Nuclear Chemistry 1. Stable isotopes Study of Atomic Nuclei and its changes a. Do not release protons or Wilhelm Conrad Roentgen...

Module 5: Nuclear Chemistry Two Categories of Isotopes Nuclear Chemistry 1. Stable isotopes Study of Atomic Nuclei and its changes a. Do not release protons or Wilhelm Conrad Roentgen neutrons (not radioactive) Discovered X-ray (1895) 2. Unstable isotopes Antoine Henri Becquerel a. Spontaneous release Relation of X-ray to his study (radioactive) Phosphorescence Marie Curie Note: The number of protons increases, Study on Uranium salts that emits neutrons must also increase to be stable radiation Pierre Curie Predicting the stability of a nuclide With her wife, they both discovered 1. No. of Neutrons must be equal or Radium and Polonium greater than the number of protons (except Hydrogen-1 and Helium-3) Note: Both of them received a nobel prize in 2. The stability is generally determined by physics with Becquerel (1903) n°/p⁺ (too much is unstable) 3. All nuclei of atomic number greater Radioactivity than 83 are unstable Spontaneous emission of radiation 4. Nuclei with even number is more stable resulting from the change in the nuclei than odd numbers 5. Nuclei that have magic numbers tend Radioactive (radionuclides /radioisotopes) to be more stable 𝐴 Radioactive decay 𝑋 𝑍 Nucleus spontaneously disintegrates A = Mass number (protons + neutrons) giving off radiation Z = Atomic Number (protons) X = Chemical Symbol Parent nuclide Result in decay or loss of energy that Nucleons transform into daughter nuclide Protons and neutrons of a nucleus Nuclide Radiation Nucleus with particular number of Particles and energy emitted protons and neutrons 40 Two ways: 20 𝐶𝑎 Calcium-40 Isotopes Same elements, different number of neutrons Same atomic number, different mass number 1. Alpha Decay 4 𝐻𝑒 5. Electron Capture 2 Occurs when an unstable proton rich nucleus draws in a surrounding electron Occurs when two protons and two Atomic number of the nucleus decrease neutrons (helium nucleus) are emitted by one from the nucleus of the parent atom. Not usually hazardous outside the body but can cause damage if ingested 0 2. Beta Decay −1 𝑒 When a nucleus contains too many neutrons Transformed into a proton and an electron with the electron ejected from the nucleus They have the same charge and mass a electrons, can be stopped by few millimeters of aluminum or a layer of clothing More hazardous if ingested or inhaled 0 3. Gamma Decay 0 𝑌 When nucleus emits a high energy form of electromagnetic radiation (gamma ray photon) Results when the nucleus decays from an excited state to a lower state, Mass defect photons are emitted by electrons Difference between the total mass of returning to a lower state the separate nucleons added together Parent nuclide does not change compared to the mass of the nucleus because no particles are physically when all the nucleons are together in emitted the nucleons Gamma rays are more penetrating It requires several inches of lead, steel, or concrete to be stopped 0 4. Positron Emission 1 𝑒 The conversion of a proton into a neutron with the emission of a positron n°/p+ is very low Same as electron in mass but of opposite charge Nuclear Fission Process when heavy nuclei splits into two or more smaller nuclei with some subatomic particles and energy Nuclear Fusion Combination of two light nuclei forming a heavier nuclei releasing enormous amounts of energy Lattice Radiocarbon dating An infinite array of regularly - spaced Approximate age of an object is points determined based on the amount of a certain nuclides present Note: not all lattice points need coincide with unit cell vertices Module 7: Basic Concept of Crystal Structure Primitive Crystallography unit cell use every lattice points as a unit Began only in the latter part of 18th cell vertex century Experimental science of the Non-Primitive arrangement of atoms in solids Contains extra lattice points not at the Originates from the greek words: (1) corners “Crystallon” means cold drop/frozen drop referring to all solids with some degree of transparency and (2) “grapho” means “write” Crystal Any solid materials whole structure is highly ordered and symmetrical over macroscopic distances Made of an array of atoms, ions, or molecules and packed together in a regular pattern Unit Cell Smallest portion of crystal lattice that is repeated through space without rotation and without gaps or overlaps  Simple Cubic 8 4 Volume of atoms : π𝑟³ 8 3 Volume of cube : 8𝑟³ π 𝐴𝑃𝐹 = 6 = 52% Body Centered 4 Volume of atoms : 2 π𝑟³ 3 4 Volume of cube : ( √3 𝑟)³ √3π 𝐴𝑃𝐹 = 8 = 68% Face Centered 4 Volume of atoms : 4 π𝑟³ 3 Volume of cube : (2√2𝑟)³ π 𝐴𝑃𝐹 = 3√2 = 74% Coordination Number (CN) Numbers of nearest neighbors that each atom has Simple Cubic Unit Cell = 6 CN Body Centered Unit Cell = 8 CN Face Centered Unit Cell = 12 CN Atomic Packing Factor Used to express the percent of an object is made of atoms against its empty space Indicates how atoms are packed tightly and can be viewed as volume density 𝑉𝑜𝑙𝑢𝑚𝑒 𝑜𝑓 𝐴𝑡𝑜𝑚𝑠 𝐴𝑃𝐹 = 𝑉𝑜𝑙𝑢𝑚𝑒 𝑜𝑓 𝑢𝑛𝑖𝑡 𝑐𝑒𝑙𝑙 Module 6: Solid, Liquid, and Gaseous Fuels Physical state Fuels are categorized as solid, liquid, Fuels and gas. Substances that burn to release energy. They exothermically react with oxygen Occurrence in a process called combustion. They are grouped as primary or natural Contain carbon and hydrogen as main and secondary or prepared. combustible elements. Used for generating electricity to run Classification of Fuels machines and appliances; manufacturing; heating and cooling; transportation and cooking. This chemical equation shows how the combustion process happens. Always remember that combustion products are always carbon dioxide and water. Fuel + oxygen → combustion products + heat CxHy + O2 → CO2 + H2O + heat Primary Fuels Fuels are not created equal. These fuels are naturally occurring such Different fuels are used for different as coal, crude oil and natural gas. needs. Those are the fuels that can be mined, Usage of fuels depends on its cost, reaped, extracted, harvested, or availability, safety and energy content. harnessed directly. They are commonly referred to as fossil Characteristics of a good fuel fuels where approximately 85% of the 1. It should easily ignite in air at a world’s commercial energy comes from. reasonable degree. The burning of fossil fuels by humans is 2. It should have high specific heat the major cause of carbon dioxide meaning it produces a lot of heat. emissions, one of the greenhouse gases 3. It should have low content of that triggered global warming. non-combustible materials in the form of ash. Secondary Fuels 4. It should not produce harmful products Originated from primary or naturally which adversely affect the environment. occurring ones through different 5. It should be low cost. physical or chemical processes. 6. Easy storage and transportation. 7. Low moisture and ash content. Solid Fuels This fuel is basically the first one ever Fuels can be classified based on their physical used by man in early civilization. Wood state and occurrence. was used to make fire.  Coal became so significant from firing 3. Formation of bituminous coal. furnaces up to the most important a. Further compaction and heating development of the industrial revolution, results in a more carbon-rich coal the discovery of the steam engine. called bituminous coal. Solid fuels are cheap, readily available, b. It contains about 85% carbon, simple to mine and easy to ship. readily burns but generates a lot However, it is a nonrenewable resource of smoke. since it takes thousands of years to form. 4. Formation of anthracite coal. Coal a. A high-grade coal called A fossil fuel and is considered as the anthracite is formed when the largest source of energy as well as the rock undergoes metamorphism. primary source of carbon dioxide b. It is a dark hard coal consisting of emissions worldwide. 90-95% carbon and burns cleanly. This type of coal has high How is coal formed? heat content and low sulfur It is formed from plant remains whose content. physical and chemical properties were transformed by environmental action to Why do you think coal is important? form a solid material. As a primary fuel, coal is used to generate steam by means of heat and Steps on how coal is formed. combustion which in turn is used for running turbines to generate electricity 1. Formation of peat. in power plants. a. Organic matter from plants It is one of the most abundant fuels in accumulates in swamps. Then, as nature, is inexpensive and can easily be the plants die and get buried, transported. they compact to become peat. However, coal is a non-renewable b. As time goes by, more resource and creates environmental compaction happens thereby problems like excessive carbon dioxide losing water resulting in three emission. different grades of coal. Coal mining affects land and is considered dangerous. 2. Formation of lignite. a. Volatile compounds like water Coke and methane are driven off by Obtained when coal is heated strongly the compaction of peat due to in the absence of oxygen in a process burial thus soft-brown colored called carbonization or coking. organic-rich coal called lignite is Has a high carbon content and low ash formed. and sulfur content which makes it very b. It contains 20-30% of carbon and highly priced in the market. 60% moisture. It does not burn It is hard and porous that’s why it is efficiently utilized as a metallurgical fuel. It is used in industries requiring uniform heating and high temperatures.  Refined Petroleum Products Charcoal Man-made products are generally Petroleum products prepared by burning wood and Refined from crude oil by means of sometimes animal matter and catalytic cracking and fractional extinguishing the fire just before they distillation. turn into ash. This includes transportation fuels, oils for When ignited, the carbon in charcoal heating and production of electricity, combines with oxygen producing plastics and even asphalt. carbon dioxide, carbon monoxide, They are also found in cosmetics, water, other gases, and a significant medications, sunglasses and even in our amount of energy. smartphones. Liquid Fuels The following are some essential liquid fuels: This type of fuel originated from the fossilized deposits of dead plants and 1. Gasoline or petrol animals by exposure to heat and a. A mixture of volatile, flammable pressure in the Earth’s crust. liquid hydrocarbons used as fuel Vapors from the liquid are flammable for internal-combustion engines. and not the liquid itself. They burn b. It is also used as a solvent for oils without dust and ash and are easy to and fats. transport through pipes. c. Became the preferred Nevertheless, liquid fuels pose a bigger automobile fuel because of its threat for being a fire hazard, high energy of combustion and specifically the highly flammable and capacity to mix readily with air in volatile ones. They also need special a carburetor. storage containers and yield bad odors too. 2. Kerosene (Paraffin Oil) a. Flammable hydrocarbon liquid Crude Oil commonly used as a fuel. Naturally occurring, unrefined b. Pale yellow or colorless and has petroleum products comprised an unpleasant characteristic hydrocarbon deposits and other odor. organic substances. c. It is used for burning in kerosene This fuel is trapped in sedimentary rocks lamps and domestic heaters or in the Earth’s crust at varying pressures furnaces, as a fuel or fuel depending on depth. component for jet engines, and These fluids are collected using offshore as a solvent for greases and drills and refined to usable petroleum insecticides. products. Almost all liquid fuels that are commercially available originated from this crude oil.  3. Diesel fuel (Diesel Oil) This material then settles on the ocean floor a. Combustible liquid used as fuel and combines with inorganic material that for diesel engines, ordinarily flows to the ocean. obtained from fractions of crude oil that are less volatile than the It is this sediment on the ocean floor that then fractions used in gasoline becomes oil and natural gas over many years. b. It releases more energy on combustion than equal volumes Geological changes in the Earth's crust bring of gasoline these deposits up closer to the surface, making c. Generally produce better fuel them somewhat easier to access. economy than gasoline engines. Biogas Gaseous Fuels It is a type of biofuel that is naturally These fuels are obtained either naturally produced from the decomposition of or by the treatment of a solid or liquid organic waste. fuel. Microbes nourishing on the biomass They have lower energy content than serve the major role in the biogas liquid fuels but produce very low production process. greenhouse gas when burned. The breakdown of organic substances like food scraps and animal waste in the Natural Gas absence of oxygen (anaerobic Colorless highly flammable gaseous surrounding) releases a mixture of gases hydrocarbon whose major composition mainly composed of methane and is methane and with trace amounts of carbon dioxide. other components. It is a renewable and environmentally The decomposition of decaying matter friendly fuel made from 100% local of animals and plants occurs deep feedstocks that is fit for a variety of uses down the Earth’s crust resulting in their including road vehicle fuel and industrial conversion to hydrocarbon fuels. uses. A fossil fuel, natural gas is used for electricity generation, heating, and Producer Gas cooking and as a fuel for certain Mixture of flammable gases (principally vehicles. carbon monoxide and hydrogen) and It is essential as a chemical feedstock in nonflammable gases (mainly nitrogen the manufacture of plastics and is and carbon dioxide) made by the required for a great selection of other partial combustion of carbonaceous chemical products such as fertilizers and substances, usually coal, in an dyes. atmosphere of air and steam. Has lower heating value than other The formation of natural gas starts in warm, gaseous fuels, but it can be shallow oceans where enormously tiny dead manufactured with relatively simple organic matter - classified as plankton, drops equipment; it is used mainly as a fuel in to the ocean floor. large industrial furnaces. Liquified Petroleum Gas (LPG) Module 11: Chemistry on the Environment It is any of several liquid mixtures of the volatile hydrocarbons such as propene, The Earth's Atmosphere propane, butene, and butane. The normal components are propane The atmosphere helps protect living organisms and butane. It was used as early as 1860 from genetic damage by solar ultraviolet for a portable fuel source, and its radiation, solar wind and cosmic rays. production and consumption for both domestic and industrial use have The atmosphere of Earth is mostly composed of expanded ever since. nitrogen (78%), oxygen (21%), argon (0.9%) with LPG reaches the domestic consumer in carbon dioxide and other gases in trace cylinders under relatively low pressures. amounts. The largest part of the LPG produced is used in central heating systems, and the Nitrogen next largest as raw material for A gas which is fixed by bacteria and chemical plants. lightning to produce ammonia which is Commonly used as fuel for gas used in the building of nucleotides and barbecue grills and gas cooktops and amino acids. ovens, for gas fireplaces, and in portable heaters. Oxygen In Europe, LPG water heaters are A gas used by most organisms for common. It is also used as an engine respiration. fuel and for backup generators. Unlike diesel, LPG can be stored nearly Argon indefinitely without degradation. A noble gas obtained from the air as a byproduct of the production of oxygen Fuels are really one of the most vital necessities and nitrogen. we need to live, they power our life. Yet, the Other noble gases in trace amounts are same fuels, specifically what we call fossil fuels, neon, helium, krypton, and xenon. are also the major givers of pollution that we are facing around the globe. Carbon dioxide One of the trace gases and used for The more production and consumption on our photosynthesis by photosynthetic algae, part, the more environmental issues we are plants and cyanobacteria. facing as well Other trace gases are methane, hydrogen, nitrous oxide, ozone, iodine, carbon monoxide, and ammonia. Water vapor A gas found in the lower layer or altitude of the atmosphere. It accounts for roughly 0.25% of the atmosphere by mass. Carbon When carbon is stored in different natural Main component of biological reservoirs other than the ocean, land, or the air compounds and many mineral deposits particles it tends to be released into the like limestone. atmosphere as greenhouse gases, having an impact on climate change. Carbon cycle Exchange of Carbon among four The increased use of fossil fuels has drawn reservoirs: the atmosphere, the oceans, concern in the carbon cycle because of the land, and fossil fuels. imbalance in the release and consumption of Carbon may be transferred from one carbon dioxide in nature. Hence, this led to reservoir to another in seconds (the the elevated level of greenhouse gases. fixation of atmospheric CO2 into sugar through photosynthesis) or over Air pollutants can be released directly into the decades or millennia (the atmosphere (primary emissions) or can form as accumulation of fossil carbon like coal, a result of chemical interaction involving oil, gas) through deposition and precursor substances. diagenesis of organic matter. Sources of emission Importance of carbon cycle Man-made sources 1. Carbon forms the structure of all life on Burning of fossil fuels coming from Earth as it makes up about 50% of the households, industry, electricity dry weight of all life forms. generation and transport; 2. The carbon cycle approximates the Industrial processes and solvent use flows of energy around the Earth, and exemplified by chemical and mining the metabolism of every system- be it industries; natural, human, or industrial. Agriculture: Most farm-related emissions 3. The Earth's average temperature come in the form of methane (CH4) without greenhouse gases would be from cattle belching and nitrous oxide −33°C. Carbon, in the form of carbon (N2O) from natural or synthetic fertilizers dioxide (CO2) and methane (CH4), and wastes to soils. contributes to a natural greenhouse Waste treatment: These treatment plants effect that has kept the planet warm produce direct emissions of greenhouse enough to evolve and support life. gases such as carbon dioxide (CO2), methane (CH4), and nitrous oxide Carbon cycle affects Global Warming? (N2O). The carbon cycle plays a key role in regulating Natural sources Earth's global temperature and climate by Volcanic eruptions. These emit water controlling the amount of carbon dioxide in vapor and toxic gases into the the atmosphere. atmosphere such as carbon dioxide, The greenhouse effect itself is a naturally sulfur dioxide, hydrogen sulfide, occurring phenomenon that makes Earth hydrochloric acid and carbon warm enough for life to exist. monoxide.  Windblown dust or Soil dust. This is Nitrous Oxide (N2O) emitted through wind erosion and wildfires. Properties: A colorless, non-flammable gas with a sweetish odor, commonly known as Carbon Dioxide (CO2) "laughing gas", and sometimes used as an anesthetic Properties: A colorless odorless gas consisting of molecules made up of two oxygen atoms and Sources: It is found and naturally produced in one carbon atom oceans and rainforests. It is also a powerful gas produced by soil cultivation practices, Sources: It is released through natural especially the use of commercial and organic processes like respiration and volcano fertilizers, fossil fuel combustion, nitric acid eruptions production, and biomass burning. Human activities such as deforestation, land Effects: Nitrous oxide has an atmospheric use changes, and burning fossil fuels contribute lifetime of 110 years. It is not only a greenhouse to its release in the environment. gas, but also an ozone destroyer. Effects: The excessive rise of CO2 Sulfur Hexafluoride (SF6) concentration in the atmosphere contribute to change in temperature Properties: It is an inorganic, colorless, odorless, non-flammable, non-toxic but extremely Methane (CH4) potent greenhouse gas. It is a hypervalent molecule consisting of six fluorine atoms to a Properties: A colorless, odorless non-toxic gas central sulfur atom. consisting of molecules made up of four hydrogen atoms and one carbon atom It is SF6 is very persistent with an atmospheric lifetime of more than a thousand years. Sources: It is produced through natural sources and human activities, such as decomposition Sources: It comes from electric power plants. It of wastes in landfills, agriculture, and especially is an excellent electrical insulator. rice cultivation, as well as ruminant digestion and manure management associated with Effects: It has a global warming potential of domestic livestock. 23,900x that of CO2 when compared over a 100-year period. Sulfur hexafluoride is inert in Effects: Affects climate by increasing Earth's the troposphere and stratosphere temperature. Sea-salt spray (Sea salt aerosol) It has a global warming potential of 34 Contributes significantly to global gas compared to 1 only for CO2 over a 100-year emission. period. It is thought to be the dominant contributor to direct scattering of solar radiation and is believed to be an important source of cloud droplets in the remote marine environment. Volatile organic compounds (VOCs) Earth will become warmer. Some regions may These are chemical substances welcome warmer temperatures, but others may produced and emitted by plants and not. other organisms in gaseous form, Warmer conditions will probably lead to more specifically composed of carbon. evaporation and precipitation overall, but individual regions will vary, some becoming wetter Changing the Global Climate and others dryer. When carbon is stored in different natural A stronger greenhouse effect will warm the oceans reservoirs other than the ocean, land, or the air and partially melt glaciers and other ice, increasing particles it tends to be released into the sea level. Ocean water also will expand if it warms, atmosphere having an impact on climate contributing further to sea level rise. change such as: Some crops and other plants may respond favorably to increase atmospheric CO2, growing Influential greenhouse gases in the form more vigorously and using water more efficiently. of air pollutants can cause depletion of the ozone layer in the atmosphere. Higher temperatures and shifting climate patterns ○ Such depletion results in the may change the areas where crops grow best and breaking down of the earth's affect the makeup of natural plant communities. ozone layer. ○ This layer covers the entire planet Types of Soil and protects life on earth by absorbing harmful Ultraviolet-B Soil (UV-B) radiation from the sun. Round/angular < 2mm to > 0.05mm Ozone depleting substances damage “light soils” the ozone layer, allowing the UV Feels gritty radiation to pass through which causes Large particles with large spaces many problems from skin cancer and between them cataracts in people to damaged farm Drains quickly crops. Fewer nutrients Not good for growing plants Clay Soil < 0.002mm Heavy soil 25% clay Small spaces between particles Drains slowly Can be molded to shape Add water – swells Water evaporates – shrinks and become hard Silt Soil Contain ≥ 20% organic carbon. < 0.05 mm to > 0.002 mm Thin in some soils, thick in others, and not Fine medium-sized particles present at all in others Smaller than sand Floury powdery A Horizon (Top Soil) Erosion by glaciers Seeds germinate and plant roots grow Light and moisture retentive soil in this dark colored layer. High fertility rate This dark decomposed organic matter is Easily compacted called "humus". Drains & holds moisture well The technical definition of an A horizon Prone to be washed away may vary between the systems, but it is most commonly described in terms Peat Soil relative to deeper layers. "A" horizons High in organic matter and retains a may be darker in color than deeper large amount of moisture. layers and contain more organic Rarely found in a garden and often matter, or they may be lighter but imported into a garden to provide an contain less clay or pedogenic oxides. optimum soil base for planting. E Horizon (Eluviation Layer) Chalk Soil Used to label a horizon that has been Can be either light or heavy but always significantly leached of its mineral highly alkaline due to the calcium and/or organic content, leaving a pale carbonate or lime within its structure. layer largely composed of silicates or As these soils are alkaline, they will not silica. support the growth of ericaceous plants These are present only in older, that require acidic soils to grow. well-developed soils, and generally occur between the A and B horizons. Loam Soil Mixture of sand, silt and clay that are B Horizon (SubSoil) combined to avoid the negative effects Consists of mineral layers which are of each type. significantly altered by pedogenesis, These soils are fertile, easy to work with mostly with the formation of iron oxides and provide good drainage. and clay minerals. Depending on their predominant Usually brownish or reddish due to the composition they can be either sandy or iron oxides, which increases the chroma clay loam. of the subsoil to a degree that it can be distinguished from the other horizons. Layers of Soil Can accumulate minerals and organic matter that are migrating downwards O Horizon (Organic) from the A and E horizons. The top, organic layer of soil, made up This layer is also known as the illuviated mostly of leaf litter and humus or illuvial horizon (decomposed organic matter). The layer has a high percentage of C Horizon (Regolith) organic matter. Consists of slightly broken up bedrock.  Plant roots do not penetrate into this Soil Structure layer; very little organic material is found Soil structure refers to the grouping of in this layer. soil particles (sand, silt, clay, organic This layer is little affected by matter, and fertilizers) into porous pedogenesis. compounds. Clay illuviation, if present, is not ○ These are called aggregates. significant. Soil structure is important for plant The absence of solum-type growth, regulating the movement of air development (pedogenesis) is one of and water, influencing root the defining attributes. development and affecting nutrient The C horizon forms either in deposits availability (e.g., loess, flood deposits, landslides) or it formed from weathering of residual The basic types of aggregate arrangements bedrock are 1. Granular R Horizon (Bedrock) 2. Blocky Denote the layer of partially weathered 3. Prismatic or unweathered bedrock at the base of 4. Massive (Platy) the soil profile. Unlike the above layers, R horizons Soil Porosity largely comprise continuous masses (as Refers to the pores within the soil. opposed to boulders) of hard rock that Porosity influences the movement of air cannot be excavated by hand. and water; healthy soils have many If there is no lithologic discontinuity pores between and within the between the solum and the R horizon, aggregates. the R horizon resembles the parent Poor quality soils have few visible pores, material of the solum. cracks or holes. Characteristics of Soil Soil Color Produced by the minerals present and All soils contain mineral particles, by the organic matter content. organic matter, water and air. The combinations of these determine Soil Composition the soil’s properties: its texture, structure, porosity, chemistry and color. Soil is composed of biotic and abiotic. Approximately consist od 50% solids and Soil Texture 50% consist of water and air Soil is made up of different-sized Soil in solid phase is stable in nature particles. Soil in air and water may vary Soil texture refers to the size of the particles that make up the soil and Water is a critical agents in soil development depends on the proportion of sand, silt due to its involvement in the dissolution, and clay-sized particles and organic precipitation, erosion, transport, and deposition matter in the soil. of the materials of which a soil is composed. Most common minerals found in soil that Widespread Pollution supports plant growth are phosphorus, Covers extensive areas and has several potassium, and nitrogen gas. Common causes, the reasons for which are minerals include calcium, magnesium, and difficult to identify. sulfur Cases such as these involve the spreading of pollutants by Soil Remediation air-ground-water systems and seriously Scientific approach with the affect human health and the collaboration of varying fields of environment sciences which includes engineering, chemistry, microbiology, soil biology, Human Activities that causes soil pollution geology, and environmental sciences 1. Industrial waste 2. Deforestation Why Remediate Soil? 3. Excessive use of fertilizer and pesticides REduce Contaminants 4. Garbage pollutions Clean Groundwater Better Vegetation Effects of Soil Pollution Clean Air 1. Climate Change 2. Loss of Soil fertility What affects choice of remediation? 3. Impact on human health Nature of contamination How it will affect wildlife Chemistry of water Expected degree of success Soil type and cost Physical Characteristics Types of soil remediation Temperature The measure of the average kinetic 1. In-Situ Soil Remediation (On site) energy of water molecules. 2. Ex-Situ Soil Remediation (Off site) Unit of measure: Celsius and Fahrenheit Water temperature depends on its Soil pollution geographic location (Mean Annual Anything that causes contamination in Temperature: 10 ◦C to 21◦C) the soil and degrades the soil quality It affects the aquatic life of various forms, solubility of oxygen, rate of Types of Soil pollution photosynthesis by algae and other aquatic plants, timing of reproduction, Specific Pollution and many more. Accounted for by particular causes, occurring in small areas, the reasons for Color which can be easily identified. Primarily being considered for the Land pollution such as this is normally quality of water (Colored water: unfit to found in cities, old factory sites, around drink) roadways, illegal dumps and sewage Indicates the presence of organic treatment stations. substances and potentially toxic organic materials.  Many prefer colorless water ○ heavy organic solids that settle Determination of color can help because of gravity estimate the costs for water Suspended solids: discoloration. ○ suspension of small solid particles that appear as colloid Taste and Odor Taste Chemical Characteristics ○ Produced by Simple Compounds: Sour and Salty Tastes pH ○ Produced by Complex Organic Indicates the acidity or basicity of the Compounds: Sweet and Bitter water Tastes pH scale ranges from 0 (strong acid) to 14 (strong alkali) Odor ○ Can be produced due to the Range of pH Scale in some bodies of water: decomposition of organic matter or substances added to the Fresh waters: a) Peaty upland waters = around 4.5 wastewater. b) Areas with intense photosynthetic activity ○ Can be measured through by algae: over 10 special instruments like Portable H2S meter Water for fisheries: 5.0 to 9.0 Turbidity Salinity Light-transmitting properties of water Indicates the amount of salt in water and is composed of suspended and Increases due to dissolved ions like colloidal material sodium, chloride, carbonate, and Human activity, decaying plant matter, sulfate. (Sea water: Sodium Chloride algal blooms, suspended sediments, (NaCl)) and plant nutrients can affect the It has a critical influence in aquatic water’s transparency. biota Aids in estimation of Total Suspended High Salinity makes water unsuitable for Solids (TSS) agricultural, domestic, or industrial use Useful in indicating the drinking-water quality Alkalinity Measures the capacity of water to Solids neutralize acids Total Dissolved Solids (TDS) Reflects the water’s Buffer Capacity ○ Small amounts of organic matter It protects fishes and aquatic life against and inorganic salts found in rapid pH changes water Rocks and soils, salts, certain plant activities, and certain industrial wastewater discharges influence a Classifications: stream’s alkalinity Settle-able solids: Hardness  Natural characteristics that can It is needed by aquatic organisms to enhance a water’s palatability and grow and survive acceptability for drinking purposes. It is caused by the presence of calcium Organisms that require high amount of DO: and magnesium minerals in water trout and stoneflies Two Major Type of Water Hardness: Organisms that can survive with low amount of Temporary DO: catfish, worms and dragonflies Permanent Heavy Bottle An absence or small amount of These are metallic chemical elements dissolved oxygen can severely affect the life of many aquatic organisms Biochemical Oxygen Demand (BOD) Identifies the amount of oxygen needed to oxidize the organic matter in the water body considering specific conditions like temperature, time, and oxidizing agent. It is important to assess the effect of the discharged wastewater in the receiving environment. Higher COD = Greater amount of oxidizable organic material in a sample The ratio of BOD to COD indicates the amount of organic materials in water that can be degraded by natural that are toxic at low concentration and microorganisms. has a high density Major Examples: Mercury (Hg), Arsenic Main Minerals in Water (As), Nickel (Ni), Chromium (Cr), Cadmium (Cd), Lead (Pb), Copper 1. Calcium (Cu), and Cobalt (Co) a. Important at all ages for healthy They are natural components of growth and bone development. geological environment b. There is good evidence to show Some heavy metals are necessary while that suitable calcium intake some are toxic and can lead to serious reduces the occurrence of diseases. osteoporosis and hip fractures. c. Surveys indicate that over 50% of North Americans do not consume the daily recommended intake of Dissolved Oxygen (DO) calcium. Talks about the amount of dissolved gaseous oxygen present in water  2. Magnesium None of these claims have been a. Cations of magnesium with scientifically proven and often focus on sodium and calcium are communities with extremely high commonly found in drinking fluoride intake. water. b. Supports the immune system and Water quality blood cell turnover. Refers to the chemical, physical or c. It is very important for many biological characteristics of water. metabolic functions, muscular It is a measure of the condition of water activity, and nervous activity. relative to its impact on one or more d. Responsible for relaxation of aquatic species or on human uses such muscles and for contraction as drinking and swimming. calcium is responsible. The most common standards used to e. For our proper daily movement, assess water quality relate to health of contraction and relaxation of ecosystems, safety of human contact muscle is very important. and drinking water 3. Sodium Dissolved Oxygen a. Most important mineral for Essential for a healthy aquatic balancing the electrolyte and ecosystem water in the body. Fish and aquatic animals need dissolved b. Our nervous system and cardiac oxygen to survive system require sodium to function As water temperature increases, the properly. amount of oxygen that dissolves in c. Because our diet is rich in sodium water decreases it is advised to drink water that The need for oxygen depends on the contains sodium content less species and life stage; some organisms than 20mg/l. are adapted to lower oxygen d. The excess amount of sodium conditions, while others require higher can be harmful to health and concentrations can lead to hypertension. ‘ Water temperature 4. Fluoride Physical property expressing how hot or a. Naturally found in water in some cold water is. areas, and intentionally added in Can affect the level of oxygen, as well others to reduce levels of tooth as the ability of organisms to resist decay. certain pollutants. Causes of temperature change in water Note: There is also fluoride in most toothpastes, include weather conditions, shade and for this reason discharges from urban sources of groundwater inflows. There have been some concerns of pH level (power of hydrogen) potential health risks from too much Determined value based on a defined fluoride intake. scale, similar to temperature  pH test measures the alkalinity or acidity environment, both naturally and of water synthetically. Excessive amounts of nitrates increase pH of 7 is neutral algae growth. below 7 is acidic ○ Algae can rob the water of above 7 is basic or alkaline. dissolved oxygen and eventually kill fish and other aquatic life. As pH or temperature rises, so too does Sources of nitrates may include human the toxicity to aquatic organisms and animal wastes, industrial pollutants and nonpoint-source runoff from heavily Escherichia Coli fertilized croplands and lawns. Fecal coliform bacteria that comes from Under certain conditions, high levels of human and animal waste. nitrates (10 mg/L or more) in drinking Disease-causing bacteria, viruses and water can be toxic to humans. protozoans may be present in water that has elevated levels of E. coli. Transparency Levels of E. coli can increase during Measures how far light can penetrate a flooding. body of water. Change in water clarity may be noticed Specific Conductance (SC) after heavy rains, as silt and debris can Measure of how well water can run off, causing the visibility to decrease. conduct an electrical current. Decreases in the summer when Conductivity in water is affected by plankton, silt and organic matter are inorganic dissolved solids such as more likely to be prevalent. chloride, sulfate, sodium, calcium and Measured with a Secchi disk. others. Streams that run through granite Water Impurities bedrock will have lower conductivity, Groundwater dissolves much of the and those that flow through limestone material when it percolates through soil and clay will have higher conductivity. formation , dissolved minerals and salts. High conductance readings also can It is generally harder than surface water, come from industrial pollution or urban and it usually contains more iron and runoff, such as water flowing from manganese. streets, buildings and parking lots. Water in nature is not pure. Organic compounds, such as oil, do not Suspended impurities are likely less in conduct electrical current very well, so ground water as subsurface porous soil an oil spill tends to lower the act as filter conductivity of the water. Nitrate Types of Impurities Inorganic compound that occurs under a variety of conditions in the Depending upon nature impurities can be ○ Discharge from nuclear power classified as: plants or research centers Physical Impurities discharge radioactive substances Chemical Impurities which can seriously affect human Biological Impurities health and life. Physical impurities are based on the following Acids Turbidity Waste products of some industries such ○ Indicates presence of suspended as battery factories , explosive factories or colloidal insoluble matter contain acids including coarse particles (mud, If directly discharged into river, then it sediment, sand, clay, silt etc.) will be harmful to life and will destroy self that settle rapidly on standing. purification property of water Color ○ Yellowish color indicates the Inorganic Compounds presence of chromium and Waste products of industries like appreciable amount of organic fertilization industry, oven industry matter. contain certain inorganic compounds. ○ Yellowish red color indicates the Compounds mainly consist of sulphide , presence of iron ammonia etc which are harmful to life ○ Red brown color indicates the presence of peaty matter. Chemical Impurities Taste ○ Due to the presence of dissolved Organic Compounds mineral in water produces taste, May exist in the water due to the but not odor presence of fats, protein and Odor carbohydrates. ○ Some industries components such The suspended organic compounds as trades contain strong smelling may develop due to decayed fruits and compounds which impart odor dead animals. and taste. ○ Smelling compounds are pH chlorine, hydrogen, and sulphide. It is a value that determines if a Temperature substance is acid, neutral or basic, ○ temperature influences several calculated from the number of other parameters and can alter hydrogen ions present. the physical and chemical properties of water. Water is most Biological Impurities dense at 4 degrees Celsius, or 39 degrees Fahrenheit, and is less Biological contamination of water is caused by dense at either higher or lower the presence of living organisms like algae, temperatures. bacteria, protozoa, pathogens, microbes, viruses, parasites and their eggs (cysts), etc. Radioactive substances known collectively as microorganisms and commonly called 'germs'.  Polymers The development of pathogenic bacteria , Classified as natural, semi-synthetic, and fungus, viruses etc. in water is caused due to man-made (synthetic) polymers based dead bodies and due to unhygienic discharge from source of sewage into rivers without treatment, and are responsible for water borne disease. Natural Polymers Occurs naturally which can be found in TYPES OF WASTEWATER COLLECTION SYSTEMS plants and animals Have one type of monomer 1. Sanitary Sewer Proteins, cellulose, starch, and natural a. Collects commercial and rubber household wastes (sometimes industrial) There are several parameters for classifications b. A sanitary sewer does not include of polymers based on: any storm water 1. Chemical Structures 2. Polymeric Structures 2. Storm Sewer 3. Tacticity a. Collects runoff from streets, land, 4. Thermal Behavior and roofs 5. Molecular forces 6. Methods of Synthesis 3. Combined Sewer a. Collects sanitary and stormwater. b. During storms, high flows can create short-term overloading conditions at treatment plant, impacting treatment efficiencies Module 9: Polymers Module 10: Nanomaterials Types of Nanostructures a. Cluster b. Nanotubes, fibers, and rods c. Films and coats d. Polycrystals Approaches to nanomaterials synthesis 1. Top down approach a. Bulk material is taken and machined and modify to obtain required size and shape b. Ex. production of integrated circuits by etching or lithography Nanomaterials c. Ball milling is used Materials having at least one dimensions d. Macrocrystalline structure are in nanometric scale broken down to nanocrystalline structures Nanotechnology 2. Bottom up approach Understanding and control of matter at a. Used to build from basic materials dimensions of roughly 1-100 nanometers, b. where unique phenomena enable novel applications Boundary between atoms and molecules and the macro world