ENGG 413 Environmental Science and Engineering PDF

ENGG 413 ENVIRONMENTAL SCIENCE AND ENGINEERING Main Topic 1: Ecological Concepts MATTER, ENERGY AND LIFE Introduction This lesson discusses first the difference between environmental science and environmental engineering. As a review of previous course, concepts like matter, atoms and mol...

ENGG 413 ENVIRONMENTAL SCIENCE AND ENGINEERING Main Topic 1: Ecological Concepts MATTER, ENERGY AND LIFE Introduction This lesson discusses first the difference between environmental science and environmental engineering. As a review of previous course, concepts like matter, atoms and molecules will be defined. Here, we will learn the concepts of ecology relating to energy, living organisms, ecosystems, trophic levels, and material cycles. Learning Outcomes Intended Learning Outcome 1 (Syllabus)  Acquire high level of awareness about the environment and its significance. Topic Outcomes:  Recognize the concept of ecology and their interrelation to the environment and life.  Define species, populations, communities, and ecosystems, and summarize the ecological significance of trophic levels.  To compare the ways that water, carbon, nitrogen, sulfur, and phosphorus cycle within ecosystems. Environmental Science and Engineering As defined in the book Environmental Science: A Global Concern 12th Edition, environment is from the French environner which means to encircle or surround. Environment can be defined in two:  The circumstances or conditions that surround an organism or group of organisms, or  The complex of social or cultural conditions that affect an individual or community. What is Environmental Science?  The systematic study of our environment and our proper place in it.  A highly interdisciplinary that integrates natural sciences, social sciences, and humanities in a broad, holistic study of the world around us.  Mission-oriented because it seeks new, valid, contextual knowledge about the natural world and our impacts on it.  With this, we are able to learn about the problems we have created with the environment and take responsibility of our actions.  Environmental science make us: o Aware and appreciate the natural and built environment; o Knowledgeable of natural systems and ecological concepts; o Understand the current environmental issues; and o Able to use critical-thinking and problem-solving skills on environmental issues. 1|Page ENGG 413 ENVIRONMENTAL SCIENCE AND ENGINEERING Main Topic 1: Ecological Concepts What is Environmental Engineering? Environmental engineering is a branch of engineering that aims to improve the quality of environment and promotes protection of people from adverse environmental effects like pollution. According to the U.S. Bureau of Labor Statistics, the mission of environmental engineers is to improve recycling, waste disposal, public health, and water and air pollution control (Lucas, 2014). History of Environmental Engineering (Vesilind, Morgan, & Heine, 2010) From the beginning of civilization, environmental engineers provided clean water and managed wastes as it was necessary whenever people congregated in organized settlements. In the ancient cities, the availability of a reliable water supply became a defensive necessity. The so called engineers of antiquity were the builders of wells and aqueducts. They were also the people who built the city walls and moats, as well as the catapults and other engines of war. During mid-1700s, the term “civil engineering” was born as engineers who built facilities for the civilian population began to distinguish themselves from the engineers primarily engaged in matters of warfare. In the formative years of the United States, engineers were mostly self-educated or were trained at the newly formed United States Military Academy. With the arrival of industrialization, unsanitary conditions in the cities were unbelievably great due to the lack of water and waste management. Though, there was no public outcry until they found out that water carry diseases. From then on, the civil engineers were also tasked to make sure the water would not be a vector for disease transmission. In the late 19th century, the major objective was to eliminate the waterborne disease. Public health became a primary concern of the civil engineers as they were entrusted with providing water supplies to the population centers. The civil engineers who were concerned with the drainage of cities and the provision of clean water supplies became public health engineers (in Britain) and sanitary engineers (in the United States). Elements of Life  Ecology is defined as the scientific study of relationships between organisms and their environment.  It is essential in ecology to understand the function of nutrients and energy in a system that is where they come from and where they go.  We can understand life based on the movement of matter and energy that is from living organisms to ecosystem.  The foundations of organisms are the carbon-based (organic) compounds. Matter - Everything that takes up space and has mass. - Four states of matter are: Solid, Liquid, Gas and Plasma - Water is the best example of matter as it can be in solid (ice), liquid (drinking water), or gas (water vapour). 2|Page ENGG 413 ENVIRONMENTAL SCIENCE AND ENGINEERING Main Topic 1: Ecological Concepts Source: (Bellati, 2018) - Examples of plasma are sun, lightning and very hot flames. It occurs when matter is intensely heated that causes electron released and particles are ionized (electrically charged). Source: (Helmenstine, Learn How to Identify Plasma With These Examples, 2019) Conservation of Matter - “Matter is neither created nor destroyed, rather, it is recycled over and over again.” - It may happen that the molecules making up a body may contain atoms that once were part of the body of a dinosaur. - Since chemical elements are used and reused by living organisms it is possible that they contain atoms that were part of many smaller prehistoric organisms. - As defined matter does not disappear, it just goes somewhere. 3|Page ENGG 413 ENVIRONMENTAL SCIENCE AND ENGINEERING Main Topic 1: Ecological Concepts How does Conservation of Matter apply to Environmental Science? Conservation of Matter explains that the components of environmental systems are intricately connected that is all matter comes from somewhere, and all waste goes somewhere. Like for example, when we throw away our wastes, they don’t really go “away,” they just go somewhere else, to stay there for a while and then move on. Elements - Substances that cannot be broken down into simpler forms by ordinary chemical reactions. - There are 122 known elements, 92 are natural and 30 are created under special conditions. All has distinct chemical characteristics. - Four Elements responsible for more than 96% of the mass of most living organisms: OXYGEN, CARBON, HYDROGEN & NITROGEN. Atoms - Smallest particles that exhibit the characteristics of an element. - Atoms consists positively charged protons, negatively charged electrons, and electrically neutral neutrons. - Protons and neutrons have approximately the same mass and they are clustered in the nucleus in the center of the atom. - Electrons are smaller compare to the other particles. They orbit the nucleus at the speed of light. Source: (Neo, 2017) - Atomic number is the characteristic number of protons per atom. - Atomic mass is the sum of protons and neutrons. - Isotopes are forms of an element that differ in atomic mass. Example: Oxygen can have one or two extra neutrons, making them the isotopes 17O or 18O, instead of the normal 16O. - Compounds are substances composed of different kinds of atoms. Example: Sodium Chloride (NaCl). - Molecules are a pair or group of atoms that can exist as a single unit. Example: Molecular oxygen (O2) 4|Page ENGG 413 ENVIRONMENTAL SCIENCE AND ENGINEERING Main Topic 1: Ecological Concepts Ions - When atoms gain or lose electrons, it acquires a negative or positive electrical charge. - Charged atoms are called ions. - 2 types of Ion: o Anions - Negatively charged ions. Example: Chlorine (Cl) readily gains electrons, forming chlorine ions (Cl− ). o Cations - Positively charged. Example: A hydrogen (H) atom can give up its sole electron to become a hydrogen ion (H +). - Acids are substances that readily give up hydrogen ions in water. - Bases are substances that readily bond with H+ ions. - pH describes the strength of an acid and base. Source: (Tunesi, 2020) Organic Compounds - The chains and rings of carbon atoms form the skeletons of organic compounds. As defined above, organic compounds are the foundation of living organisms. - Four major categories of organic compounds in living things: o Lipids (including fats and oils) o Carbohydrates (including sugars, starches, and cellulose) o Proteins (composed of chains of subunits called amino acids) o Nucleic acids (complex organic substance present in living cells, especially DNA or RNA). 5|Page ENGG 413 ENVIRONMENTAL SCIENCE AND ENGINEERING Main Topic 1: Ecological Concepts - Nucleotides carry information between cells, tissues, and organs and the sources of intracellular energy. Nucleotides form long chains called ribo nucleic acid (RNA) or deoxyribo nucleic acid (DNA) that are essential for storing and expressing genetic information. - Four kinds of nucleotides that occur in DNA: adenine, guanine, cytosine, and thyamine. Cells - Minute compartments within which the processes of life are carried out. - All living organisms are composed of cells. - Bacteria, some algae, and protozoa are single celled organisms. - Higher organisms have many cells, usually with many different cell varieties. A human being is composed of several trillion cells of about two hundred distinct types. Source: (BD Editors, 2020) ANIMAL CELL Source: (BD Editors, 2020) PLANT CELL 6|Page ENGG 413 ENVIRONMENTAL SCIENCE AND ENGINEERING Main Topic 1: Ecological Concepts - Enzymes are a special class of proteins that carry out all the chemical reactions required to create various structures. They also provide energy and materials to carry out cell functions, dispose of wastes, and perform other functions of life at the cellular level. Enzymes are molecular catalyst because they regulate chemical reactions without being used up or inactivated in the process. - Metabolism is the multitude of enzymatic reactions performed by an organism. Energy  The ability to do work, such as moving matter over a distance or causing a heat transfer between two objects at different temperatures.  It is measured in units of heat (calories) or work (joules).  Types of Energy o Kinetic Energy - energy contained in moving objects o Potential Energy - stored energy that is dormant but available for use. o Chemical Energy - stored in the food that you eat and the gasoline that you put into your car o Heat - the energy that can be transferred between objects of different temperature. Source: (Helmenstine, 10 Types of Energy and Examples, 2020)  Units of Energy o One joule (J) is the work done when one kg is accelerated at one meter per second per second. o One calorie is the amount of energy needed to heat one gram of pure water one degree Celsius. 7|Page ENGG 413 ENVIRONMENTAL SCIENCE AND ENGINEERING Main Topic 1: Ecological Concepts o A calorie can also be measured as 4.184 J. Thermodynamics - A study that deals with the transfer of energy in natural processes. - It deals with the rates of flow and the transformation of energy from one form or quality to another. - First law of thermodynamics o States that energy is conserved. It is neither created nor destroyed under normal conditions. o Example: Energy may be transformed from the energy in chemical bond to heat energy, but the total amount does not change. - Second law of thermodynamics o States that, with each successive energy transfer or transformation in a system, less energy is available to do work. Energy is degraded to lower-quality forms, or it dissipates and is lost, as it is used. o Example: When you drive a car the chemical energy of the gas is degraded to kinetic energy and heat, which dissipates, eventually, to space. o Application of second law of thermodynamics to organisms and biological systems: Organisms are organized structurally and metabolically. To maintain these processes, constant care, maintenance and supply of energy is required to keep up the organization. When energy is used by a cell to do work, some of that energy is dissipated or lost as heat. If cellular energy supplies are interrupted or depleted, the result is death. Energy for Life  Organisms such as blind shrimp, giant tubeworms, strange crabs, and bizarre clams (extremophiles - organisms that have been discovered on Earth that survive in environments that were once thought not to be able to sustain life) that live in sunless ecosystems (deep ocean floor) get energy through chemosynthesis.  Chemosynthesis is the process in which bacteria use chemical bonds between inorganic elements, such as hydrogen sulfide (H2S) or hydrogen gas (H2), to provide energy for synthesis of organic molecules. Solar Energy - essential to life. 8|Page ENGG 413 ENVIRONMENTAL SCIENCE AND ENGINEERING Main Topic 1: Ecological Concepts Two reasons why: 1. The sun provides warmth. Most organisms survive within a relatively narrow temperature range. o Above 40 degree Celsius, most biomolecules begin to break down or become distorted and nonfunctional. o At low temperatures (near 0 degree Celsius), some chemical reactions of metabolism occur too slowly to enable organisms to grow and reproduce. o The Earth's water and atmosphere help to moderate, maintain, and distribute the sun's heat. 2. Almost all organisms on the Earth's surface depend on solar radiation for life-sustaining energy. This is captured by green plants, algae, and some bacteria in a process called photosynthesis. Photosynthesis converts radiant energy into high-quality chemical energy in the bonds that hold together organic molecules. Source: (Cunnigham & Cunningham, 2012) Energy Exchange in Ecosystems Plants use sunlight, water, and carbon dioxide to produce sugars and other organic molecules. Consumers use oxygen and break down sugars during cellular respiration. Plants also carry out 9|Page ENGG 413 ENVIRONMENTAL SCIENCE AND ENGINEERING Main Topic 1: Ecological Concepts respiration, but during the day, if light, water, and CO 2 are available, they have a net production of O 2 and carbohydrates. From Species to Ecosystem Ecology – the scientific study of relationships between organisms and their environment. Species – refers to all organisms of the same kind that are genetically similar enough to breed in nature and produce live, fertile offspring. Population – consists of all the members of a species living in a given area at the same time. Biological Community – All of the populations living and interacting in a particular area. Ecosystem – (Ecological system) is composed of a biological community and its physical environment. The environment includes: o Abiotic factors - nonliving components such as climate, water, minerals, and sunlight o Biotic factors – examples are organisms and their products (secretions, wastes, and remains) and effects in a given area. Productivity - One of the major properties of an ecosystem. - The amount of biomass (biological matter) produced in a given area during a given period of time. - Two types of productivity: o Primary Productivity – e.g. photosynthesis, because it is the basis for almost all other growth in an ecosystem. o Secondary Productivity - manufacture of biomass by organisms that eat plants - A given ecosystem may have very high total productivity, but if decomposers decompose organic material as rapidly as it is formed, the net primary productivity will be low. Food Chain - A linked feeding series. Source: (The K8 School) Food Web - Interconnection of individual food chains. 10 | P a g e ENGG 413 ENVIRONMENTAL SCIENCE AND ENGINEERING Main Topic 1: Ecological Concepts Trophic Level - From the Greek trophe which means “food”. - An organism’s feeding status in an ecosystem. Source: (The K8 School) Source: (Cunnigham & Cunningham, 2012) 11 | P a g e ENGG 413 ENVIRONMENTAL SCIENCE AND ENGINEERING Main Topic 1: Ecological Concepts Producers - Organisms that photosynthesize, mainly green plants and algae. Consumers – organisms that consumes the chemical energy harnessed by the producers. o Herbivores – plant eaters, e.g. goat, cow, horse, grasshopper, etc. o Carnivores – flesh eaters, e.g. lion, hyena, caracal, wolf, etc. o Omnivores – eat both plant and animal matter, e.g. man Scavengers - Organisms that clean up dead carcasses of larger animals such as crows, jackals, and vultures. Detritivores - Consume litter, debris, and dung such as ants and beetles. Decomposer - Organisms that complete the final breakdown and recycling of organic materials such as fungi and bacteria. - These microorganisms are second in importance to producers because without their activity nutrients would remain locked-up in the organic compounds of dead organisms and discarded body wastes, rather than being made available to successive generations of organisms. Ecological Pyramids Source: (BD Editors, 2017) Definition - A graphical representation of the relationship between different organisms in an ecosystem. - The trophic levels are represented by bars that make up the pyramid. - The flow of energy in the pyramid moves up. It starts with the primary producers at the bottom, followed by the primary consumers, then secondary consumers, and so on. - The height of the bars are all be the same, it varies in width of each bar as it is based on the quantity of the aspect being measured. Types of Ecological Pyramid 1. Pyramid of numbers - Presents the number of organisms in each trophic level without any consideration for their size. Unit: number of organisms. Source: (Biology Notes for IGCSE 2014, 2014) 12 | P a g e ENGG 413 ENVIRONMENTAL SCIENCE AND ENGINEERING Main Topic 1: Ecological Concepts 2. Pyramid of biomass - Presents the total mass of organisms at each trophic level. - This type of pyramid is largest at the bottom and gets smaller going up, but exceptions do exist. - The biomass of one trophic level is calculated by multiplying the number of individuals in the trophic level by the average mass of one individual in a particular area. - Unit: g/m2 or Kg/m-2. Source: (Mondal) 3. Pyramid of productivity - Presents the total amount of energy present at each trophic level, as well as the loss of energy between trophic levels. - The most widely used type of ecological pyramid. Unlike the two other types, this can never be largest at the apex and smallest at the bottom. - It’s an important type of ecological pyramid because it examines the flow of energy in an ecosystem over time. Unit: J/m2.yr1 Source: (Mondal) 13 | P a g e ENGG 413 ENVIRONMENTAL SCIENCE AND ENGINEERING Main Topic 1: Ecological Concepts Material Cycles The water cycle distributes water among atmosphere, biosphere, surface, and groundwater. Carbon, nitrogen, and phosphorus are among the essential elements that also move through biological, atmospheric, and earth systems (biogeochemical cycles). Earth is the only planet in our solar system that provides a suitable environment for life as we know it. Maintenance of these conditions requires a constant recycling of materials between the biotic (living) and abiotic (nonliving) components of ecosystems. Hydrologic Cycle - The path of water through our environment. - The most familiar material cycle. - Water is responsible for metabolic processes within cells, for maintaining the flows of key nutrients through ecosystem and for global-scale distribution of heat and energy. Source: (Canada.ca, 2013) Evaporation - As water is heated by the sun, surface molecules become sufficiently energized to break free of the attractive force binding them together, and then evaporate and rise as invisible vapor in the atmosphere. Transpiration - Water vapor is also emitted from plant leaves by a process called transpiration. Every day an actively growing plant transpires 5 to 10 times as much water as it can hold at once. 14 | P a g e ENGG 413 ENVIRONMENTAL SCIENCE AND ENGINEERING Main Topic 1: Ecological Concepts Condensation - As water vapor rises, it cools and eventually condenses, usually on tiny particles of dust in the air. When it condenses it becomes a liquid again or turns directly into a solid (ice, hail or snow). These water particles then collect and form clouds. Precipitation - Precipitation in the form of rain, snow and hail comes from clouds. Clouds move around the world, propelled by air currents. For instance, when they rise over mountain ranges, they cool, becoming so saturated with water that water begins to fall as rain, snow or hail, depending on the temperature of the surrounding air. Runoff - Excessive rain or snowmelt can produce overland flow to creeks and ditches. Runoff is visible flow of water in rivers, creeks and lakes as the water stored in the basin drains out. Percolation - Some of the precipitation and snow melt moves downwards percolates or infiltrates through cracks, joints and pores in soil and rocks until it reaches the water table where it becomes groundwater. Groundwater - Subterranean water is held in cracks and pore spaces. Depending on the geology, the groundwater can flow to support streams. It can also be tapped by wells. Some groundwater is very old and may have been there for thousands of years. Water table - The water table is the level at which water stands in a shallow well. Note: The above definitions of terms are from (Canada.ca, 2013) Carbon Cycles The carbon cycle begins with the intake of carbon dioxide by photosynthetic organisms. Carbon (and hydrogen and oxygen) atoms are incorporated into sugar molecules during photosynthesis. Carbon dioxide is eventually released during respiration, closing the cycle. The carbon cycle is of special interest because biological accumulation and release of carbon is a major factor in climate regulation. Carbon Cycle Steps (Roy & Ladefoged) Step 1: Carbon enters the atmosphere as carbon dioxide from respiration (breathing) and combustion (burning). Step 2: Carbon dioxide is absorbed by producers (life forms that make their own food e.g. plants) to make carbohydrates in photosynthesis. These producers then put off oxygen. Step 3: Animals feed on the plants. Thus, passing the carbon compounds along the food chain. Most of the carbon these animals consume however is exhaled as carbon dioxide. This is through the process of respiration. The animals and plants then eventually die. Step 4: The dead organisms (dead animals and plants) are eaten by decomposers in the ground. The carbon that was in their bodies is then returned to the atmosphere as carbon dioxide. In some 15 | P a g e ENGG 413 ENVIRONMENTAL SCIENCE AND ENGINEERING Main Topic 1: Ecological Concepts circumstances the process of decomposition is prevented. The decomposed plants and animals may then be available as fossil fuel in the future for combustion. Source: (NESTA with modifications by UCAR, 2007) Nitrogen Cycle - Nitrogen gas molecules (N2) make up 78% of our atmosphere. - Plants rely on bacteria living in soils, in plant tissues, or in aquatic systems to capture N2. These nitrogen fixing bacteria have proteins that can break N2 bonds. - Of the many nitrogen compounds, only nitrate (NO3) and ammonium (NH4) can be used directly by plants. These are the sources of nitrogen for forming amino acids, the building blocks for complex organic compounds such as proteins. - Where oxygen is available, bacteria may combine ammonia (NH3) with oxygen to form nitrous oxide (N2O), nitric oxide (NO), nitrite (NO2), or nitrate (NO3). - In oxygen-poor conditions, such as in streambed sediments, saturated soils, or wetlands, denitrifying bacteria may remove oxygen from nitrate to form gaseous compounds, especially nitrous oxide or nitrogen gas. Conversion to these gaseous forms is known as denitrification (important in removing nitrogen from aquatic systems that suffer from eutrophication). - Nitrogen moves through the food web as organism die, decompose, or are consumed. - Decomposers, fungi and bacteria, release ammonia and ammonium ions, which then are available for nitrite formation. - Organisms also release proteins when plants shed their leaves, needles, flowers, fruits, and cones; or when animals shed hair, feathers, skin, exoskeletons, pupal cases, and silk, excrement, or urine, all of which are rich in nitrogen. 16 | P a g e ENGG 413 ENVIRONMENTAL SCIENCE AND ENGINEERING Main Topic 1: Ecological Concepts Urinary wastes are especially high in nitrogen because they contain the detoxified wastes of protein metabolism. Source: (BD Editors, 2019) Common forms of Nitrogen Name Characteristics Makes up 78% of atmosphere; can be fixed by bacteria, cyanobacteria, some Nitrogen Gas (N2) marine algae. Gaseous form; corrosive; common agricultural fertilizer that bonds with H+ to Ammonia (NH3) form NH4. Ammonium (NH4) Directly usable by plants; positive charge helps adhere to clays in soils. Ion with negative electrical charge; a step in nitrification process (conversion of Nitrite (NO2) NH4 to NO3); toxic to plants; usually present temporarily or in low quantities. Nitrate (NO3) Directly usable by plants; products of nitrification. 17 | P a g e ENGG 413 ENVIRONMENTAL SCIENCE AND ENGINEERING Main Topic 1: Ecological Concepts Diverse compounds, such as proteins; must be converted to NH4 for use by Organic Nitrogen plants. Organic to inorganic transition is mineralization. Various combinations such as NO2 (nitrogen dioxide), NO (nitric oxide), and N2O (nitrous oxide); fuel combustion in vehicles and industry produces most NOx; Nitrogen Oxides (NOx) rainfall washes NOx into soils and waterways. NO2 and N2 also result from denitrification by bacteria. Phosphorus Cycle - Phosphorus is the most important among the many elements released to ecosystem from rock formations because it is often limited in supply. - Phosphorus is an essential component of all cells. Compounds containing this element store and release a great deal of energy, so phosphorus-compounds, such as ATP, are primary participants in energy-transfer reactions in cells. - Phosphorus is also a key component of proteins, enzymes, and tissues. - Low levels of phosphorus limit plant growth. Abundant phosphorus stimulates lush plant and algal growth, making it a major water pollutant. - Phosphorus cycle is really a one-way path. This is because phosphorus has no atmospheric form, in which it can quickly recirculate. - Phosphorus travels gradually downstream, as it is leached from rocks and minerals, taken up by the food web, and eventually released into water bodies that deliver it to the ocean. - Phosphorus cycles repeatedly through the food web, as inorganic phosphorus is taken up by plants, incorporated into organic molecules, and passed on to consumers. - Though phosphorus washes down river to the ocean, where it accumulates in ocean sediments. Over geologic time, these deposits can be uplifted end exposed, so they become available to terrestrial life again. - The phosphate use for detergents and fertilizers today are mined from exposed ocean sediments millions of years old. 18 | P a g e ENGG 413 ENVIRONMENTAL SCIENCE AND ENGINEERING Main Topic 1: Ecological Concepts Source: (BD Editors, 2017) References BD Editors. (2020, June 17). Animal Cell. Retrieved July 25, 2020, from Biology Dictionary: https://biologydictionary.net/animal-cell/ BD Editors. (2017, April 28). Ecological Pyramid. Retrieved July 25, 2020, from Biology Dictionary: https://biologydictionary.net/ecological- pyramid/#:~:text=An%20ecological%20pyramid%20is%20a,represents%20the%20flow%20of%20e nergy. BD Editors. (2019, May 13). Nitrogen Cycle. Retrieved July 25, 2020, from Biology Dictionary: https://biologydictionary.net/nitrogen-cycle/ BD Editors. (2017, June 5). Phosphorus Cycle. Retrieved July 25, 2020, from Biology Dictionary: https://biologydictionary.net/phosphorus-cycle/ BD Editors. (2020, June 18). Plant Cell. Retrieved July 25, 2020, from Biology Dictionary: https://biologydictionary.net/plant-cell/ Bellati, A. (2018, October 9). The Forms of Water. Retrieved July 25, 2020, from Eniscuola: http://www.eniscuola.net/en/2018/10/09/the-forms-of-water/ Biology Notes for IGCSE 2014. (2014, April 5). #141 Food pyramids of numbers, biomass and energy. Retrieved July 25, 2020, from Biology Notes for IGCSE 2014: http://igbiologyy.blogspot.com/2014/03/109-food-pyramids-of-numbers-biomass.html 19 | P a g e ENGG 413 ENVIRONMENTAL SCIENCE AND ENGINEERING Main Topic 1: Ecological Concepts Canada.ca. (2013, September 9). Water basics: the hydrologic cycle. Retrieved July 25, 2020, from Canada.ca: https://www.canada.ca/en/environment-climate-change/services/water- overview/basics/hydrologic-cycle.html Cunnigham, W. P., & Cunningham, M. A. (2012). Environmental Science: A Global Concern, Twelfth Edition. 1221 Avenue of the Americas, New York, NY 10020: The McGraw-Hill Companies, Inc. Helmenstine, A. M. (2020, January 23). 10 Types of Energy and Examples. Retrieved July 25, 2020, from ThoughtCo.: https://www.thoughtco.com/main-energy-forms-and-examples-609254 Helmenstine, A. M. (2019, July 12). Learn How to Identify Plasma With These Examples. Retrieved JUly 25, 2020, from ThoughtCo.: https://www.thoughtco.com/examples-of-plasma-608335 Lucas, J. (2014, October 22). What Is Environmental Engineering? Retrieved July 24, 2020, from Live Science: https://www.livescience.com/48390-environmental-engineering.html Mondal, P. (n.d.). 3 Major Types of Ecological Pyramids | Pyramid of Number, Biomass and Energy. Retrieved July 25, 2020, from Your Article Library: https://www.yourarticlelibrary.com/ecology/3- major-types-of-ecological-pyramids-pyramid-of-number-biomass-and-energy/9855 NASA. (2019, October 2). Sun. Retrieved July 25, 2020, from NASA Solar System Exploration: https://solarsystem.nasa.gov/solar-system/sun/overview/ Neo. (2017, January 16). Who Discovered Atom. Retrieved July 25, 2020, from Who Invented First: http://www.whoinventedfirst.com/who-discovered-the-atom/ NESTA with modifications by UCAR. (2007). The Carbon Cycle. Retrieved July 25, 2020, from UCAR Center for Science Education: https://scied.ucar.edu/carbon-cycle Roy, G., & Ladefoged, Z. (n.d.). The Carbon Cycle Steps. Retrieved July 25, 2020, from The Carbon Cycle: https://thecarboncycledio.weebly.com/the-carbon-cycle-steps.html The K8 School. (n.d.). Food Chains and Food Webs. Retrieved July 25, 2020, from K8 School Lessons: http://k8schoollessons.com/food-chains-food-webs/ Tunesi, L. (2020, March 5). Explainer: What the pH scale tells us. Retrieved July 25, 2020, from Science News for Students: https://www.sciencenewsforstudents.org/article/explainer-what-the- ph-scale-tells-us Vesilind, P. A., Morgan, S. M., & Heine, L. G. (2010). Introduction to Environmental Engineering, Third Edition. Cengage Learning. 20 | P a g e