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Chapter 1 Q1\ Define Environmental Engineering? A\ Environmental Engineering is the application of knowledge in mathematics, natural sciences, human sciences, engineering sciences gained by study, practice and experience to the solution of the environmen...

Chapter 1 Q1\ Define Environmental Engineering? A\ Environmental Engineering is the application of knowledge in mathematics, natural sciences, human sciences, engineering sciences gained by study, practice and experience to the solution of the environmental problems. - Environmental engineers apply science and engineering principles to develop systems that protect human health and welfare and minimize the unfavorable effects of human activities on the environment. - By using the principles of biology and chemistry, environmental engineers develop solutions to environmental problems. They are involved in water and air pollution control, recycling, waste disposal, and public health issues. Q2\ What are the requirements for Environmental Engineering? A\ Creative, analytical, and detail oriented. They must have knowledge of mathematics and sciences. Q3\ List some of the environmental Engineering concerning? A\ 1- minimize the effects of acid rain 2- global warming 3- automobile emissions 4- ozone depletion 5- protect the wildlife. Scope of Environmental Engineering: 1- Provision of qualitative and quantitative water supplies. 2- The proper disposal or recycle of wastewater and solid wastes. 3- Control of water, soil and atmospheric pollution. 4- Public health – control of water borne/air borne diseases and elimination of industrial hazards. 5- The social, health and environmental impacts of technological solutions to environmental problems. 6- The effects of technological advances on the environment Major Environmental Systems: 1- Water Resource Management System. 2- Air Resource Management System. 3- Solid Waste Management System The Systems Approach to Solution of Environmental Problems is Carried Out By: 1- Looking at all the interrelated parts and their effects on one another. 2- Simplifying the system to a manageable size that behaves in a fashion similar to the real system which is natural and therefore complex Classification of Environmental Pollution Problems: 1- SINGLE-MEDIUM POLLUTION PROBLEMS (SMPP). Pollution problems that are confined to air, water, or soil. 2- MULTI-MEDIA POLLUTION PROBLEMS (MMPP). Pollution problems that are confined to air, water, or soil but also cross the boundaries from one to another. The Water Resource Management System is made up of two parts: 1- Water supply subsystem. 2- Waste water disposal subsystem Sources of Water: 1- Surface Water (streams, rivers, lakes) 2- Groundwater (wells, springs) - The nature of the source commonly determines the planning, design, operation, collection, purification, transmission, and distribution works required for the development of the water source. - Storage reservoir is used for meeting high demand during scheduled maintenance, shut down for repairs, and emergency back up during a fire outbreak. Why is the disposal of human wastes necessary? 1- To protect the health of individual, the family, and the community. 2- To prevent the occurrence of certain visuals (odor, and visual intrusion). Objectives of human wastes disposal: 1- prevent contamination of drinking water supply. 2- prevent public health hazard through accessibility to insects, being accessible to children. 3- Not cause violation of laws or regulation or regulations governing water pollution or sewage disposal. 4- prevent pollution or contamination of waters used for purposes like bathing beach, shell fish Breeding, domestic water-Supply etc. 5- control or prevent visuals due to odor or unsightly appearance. 6- comply with laws and regulations governing water pollution or sewage disposal e.g. Department of Environment (DOE). Factors affecting air pollution management: 1- Quantity 2- Quality Two major reasons for air resource management programs to be instituted: 1- The air quality has weakened and there is the need for correction. 2- The potential for a future problem is strong. Factors influencing the need for Solid Waste Management: 1- Lack of adequate land fill space. 2- Failure of existing landfills to protect surface water and ground water from pollution. 3- Fear of atmospheric emissions of cancer-causing compounds from incinerators. - The best solution to environmental pollution is waste minimization i.e. produce less waste.  Chapter 2 Q1\ Define Ecosystem? A\ Ecosystem: community of organisms interacting with one another and with the chemical and physical factors making up their environment. - An ecosystem is abiotic (non-living) and biotic (living) composition and structure is determined by the state of a number of interrelated environmental factors. The dynamics of an ecosystem involve two processes: 1- Energy flow 2- Chemical cycling *The law of conservation of energy applies to ecosystems: We can potentially trace all the energy from its solar input to its release as heat by organisms. - The second law of thermodynamics allows us to measure the efficiency of the energy conversions. Q2\ What are basic factors in environmental integrity of any system? A\ 1- Nutrient Availability 2- Temperature 3- Light intensity 4- Grazing intensity 5- Species population density Q3\ What are the ecosystem components? A\ 1- Soil: provides the living organisms found in an ecosystem with nutrients, water, a home, and a structural medium for the roots of many types of plants. 2- The atmosphere: is an important sink for oxygen, carbon dioxide, and water. 3- The sun: provides ecosystems with energy in the form of radiation which is used to generate heat and power photosynthesis. 4- Water: plays an important role in the functioning of an ecosystem. 5- Living organisms Q4\ List the two types of Living organisms? A\ 1- Producers: They that can build their own food. 2- Consumers: They can not configure their own food. - All ecosystems are open systems. (open system: energy and matter are transferred in and out) - Plants are the only organisms found in ecosystems that can chemically fix energy. Heterotrophic: an organism that can not fix carbon and uses organic carbon for growth. * if the heterotroph uses light for energy, then it is considered a photoheterotroph. * if the heterotroph uses chemical energy, it is considered a chemoheterotroph. Decomposers: convert organic matter back into its inorganic constituents. (This process also provides the decomposers with energy to run their metabolism) - Energy and matter can also move from one ecosystem to another. (This movement is done through processes like seed dispersal, animal migration, leaching, and erosion) - The efficiency of energy transfer between trophic levels is usually less than 20%. Q5\ Draw Diagram of the pond ecosystem and show the Basic units? A\ 1- Abiotic substances 2- Producers 3- Primary consumers 4- Secondary consumers 5- Tertiary consumers 6- Decomposers Q6\ Draw flow chart for an example of food chain? A\ Grass > Cows > Human (humans eat cow’s meat Chapter 3 Q1\ Define wastes? A\ Waste: it may be a solid, a semisolid, a liquid, or a contained gaseous material which possessing a substantial hazard to human health and the environment. - Environmental pollution affects not only people, animals and vegetation but also the wider environment such as mountains, rocks, lakes, rivers and so on. Q2\ What are the three general characteristics of environmental pollutants? A\ 1- Pollutants don't recognize boundaries, i.e. they are transboundary. 2- Many of Pollutants can't be degraded by living organisms and therefore stay in the ecosphere for many years. 3- Pollutants destroy biota and habitat (surroundings, environment). Q3\ What are the pollutants classification according to biological decomposition? A\ 1- Biodegradable: the ones that can be broken down and processed by living organisms, including organic waste products, phosphates, and inorganic salts. 2- Non-Biodegradable: the ones that cannot be decomposed by living organisms and therefore persist in the ecosphere for extremely long periods of time. They include plastics, metal, glass, some pesticides and herbicides, and radioactive isotopes. - Biodegradable pollutants are only “temporary nuisances” that can be neutralized and converted into harmless compounds. Q4\ List types of environmental pollution according to its effects? A\ 1- Air pollution 2- Water pollution 3- Soil pollution (contamination) Q5\ What are the effects of air pollution on human? 1- Reduced lung functioning 2- Irritation of eyes, nose, mouth and throat 3- Reduced energy levels 4- Headaches and dizziness 5- Cancer 6- Premature death Q6\ What are the effects of water pollution on human? Q\ 1- Waterborne diseases caused by polluted drinking water. Example: A- Typhoid B- Amoebiasis. 2- Waterborne diseases caused by polluted beach water. Examples: A- Rashes, ear ache, pink eye B- Respiratory infections 3- Conditions related to water polluted by chemical (such as pesticides, persistent organic pollutants, heavy metals). Examples: A- Cancer B- Damage to the nervous system C- Liver and kidney damage D- Damage to the DNA Water pollution may also result from interactions between water and contaminated soil, as well as from deposition of air contaminants (such as acid rain): 1- Damage to people may be caused by fish foods coming from polluted water. 2- Damage to people may be caused by vegetable crops grown / washed with polluted water. Q7\ What are the effects of soil pollution on human? 1- Causes cancers including leukemia 2- Causes neuro muscular blockage as well as depression of the central nervous system 3- Causes headaches, nausea, fatigue, eye irritation and skin rash 4- Contact with contaminated soil may be direct (from using parks, schools etc) or indirect (by inhaling soil contaminants which have vaporized) 5- Soil pollution may also result from secondary contamination of water supplies and from deposition of air contaminants (for example, via acid rain) 6- Contamination of crops grown in polluted soil brings up problems with food security 7- Since it is closely linked to water pollution, many effects of soil contamination appear to be similar to the ones 9 caused by water and air contamination. Q8\ Classify Source Pollution and Differentiate between them? A\ 1- Point source pollutants. 2- Non-point source pollutants. Point source pollutants Non-point source pollutants (characteristics) (characteristics) Easier to control Uncontrollable More readily identifiable and measurable Difficult or impossible to trace to a source Generally, more toxic Have the potential for maintaining a relatively long active presence on the global ecosystem - May result in long term, chronic (and endocrine) effects on human health and soil- aquatic degradation. - Enter the environment over an extensive area and sporadic timeframe Q9\ Draw the cycle structure of water, carbon and Nitrogen in the environment?  Chapter 4 Q1\ What are the four major categories laboratory tests for wastewater? 1- Organics 2- Solids 3- Nutrients 4- Physical Properties Q2\ Interaction of wastewater analytical categories and laboratory tests? 1- The solids content 2- Nitrate and Phosphorus 3- Odors and tastes 4- Color 5- Pathogenic Organisms 6- Dissolved Oxygen (DO) 7- Biological Oxygen Demand (BOD) 8- Chemical Oxygen Demand (COD) Q3\ Draw a figure for solids content of an urban wastewater? Q4\ What are varies form of Nitrogen in an urban wastewater? 1- Organic nitrogen (1- Unbiodegradable soluble and particulate 2- biodegradable) 2- Inorganic nitrogen (ammonia) The concentration of Dissolved Oxygen (DO) in a water sample is significantly influenced by: 1- Temperature 2- Salinity 3- Atmospheric pressure  2 ‫ﺑﺪاﯾﺔ اﻟﻤﺪ ﺗﺮم‬ Q5\ Define Biochemical oxygen demand? The amount of oxygen required to oxidize an organic compound by aerobic biological organisms to carbon dioxide, ammonia, and water. - The BOD value is most commonly expressed in milligrams of oxygen consumed per liter of sample during 5 days of incubation at 20 °C and is often used as a strong alternate of the degree of organic pollution of water. - The basis for the BOD test is that nearly all organic compounds can be fully oxidized to carbon dioxide. - The five-day completion gap is a natural disadvantage of the test because wastewater treatment system staff cannot use it to make real-time operational adjustments. - To eliminate the interference due to nitrifying bacteria inhibitors (methylene blue, thiourea, allyl thiourea) can be added. The BOD obtained is called Carbonaceous BOD or CBOD. The extra BOD resulting from the presence of nitrifying bacteria is called Nitrogenous BOD or NBOD. What affects the BOD test? (‫)ﻣﻦ ﻋﻨﺪي‬ Temperature, Nature of the organic matter, and type of microorganisms. - Nitrifying bacteria oxidize ammonia, consuming extra oxygen. Why do we limit the BOD test at 5 days? (‫)ﻣﻦ ﻋﻨﺪي‬ 1- To maximize the effect of the presence of nitrifying organism. 2- Five days represents the oxygen demand for respiration by the aerobic biological microorganisms in the sample. - BOD test measures process efficiency. BOD tests are routinely performed for a number of reasons: 1- used to determine compliance. 2- An approximate measure of the degradation capacity of organic matter by microorganisms. 3- Can be used to preliminary design some treatment facilities. 4- Is a measure of process efficiency. BOD test significant limitations: 1- Does not have stoichiometric validity at all times since the microorganisms go through different phases of utilization of organic matter. 2- Lengthy test. 3- Only biodegradable organics are measured. 4 ‫ ﻣﻦ ﺷﺎﺑﺘﺮ‬17 ‫ و‬16 ‫ و‬15 ‫ اﻟﻤﻮﺟﻮد ﻓﻲ ﺳﻼﯾﺪ‬BOD Curve ‫ذاﻛﺮ اﻟـ‬ ‫ ﻛﻞ ﻣﺎﻛﺎن اﻟﻤﺎء أﻧﻈﻒ‬COD ‫ و اﻟـ‬BOD ‫ﻛﻞ ﻣﺎﻗﻠﺖ ﻧﺴﺒﺔ اﻟـ‬  20 ‫ ﺗﺒﺪأ ﻣﻦ ﺳﻼﯾﺪ‬4 ‫ ﺷﺎﺑﺘﺮ‬BOC ‫ذاﻛﺮ أﻣﺜﻠﺔ اﻟـ‬ Chemical Oxygen demand (COD): the amount of oxygen required to oxidize an organic compound with a strong oxidizing agent under acidic conditions to carbon dioxide, ammonia, and water. - the amount of oxygen consumed in the chemical oxidation of organic matter by strong oxidant (e.g., potassium dichromate). ‫ﺗﻌﺮﯾﻒ ﻣﻦ ﺑﺮا اﻟﻤﻨﮭﺞ‬ - the chemical oxygen demand (COD) test is commonly used to indirectly measure the amount of organic compounds in water. - The basis for the COD test is that nearly all organic compounds can be fully oxidized to carbon dioxide with a strong oxidizing agent under acidic conditions. - COD doesn’t have nitrifying bacteria. Nitrification: the process of ammonia being converted into nitrate. Oxidizing agents used to determine COD: ceric sulphate, potassium iodate, and potassium dichromate K2Cr2O7. - Potassium dichromate is a strong oxidizing agent under acidic conditions. - Potassium dichromate has been shown to be the most effective: it is relatively cheap, easy to purify, and is able to nearly completely oxidize almost all organic compounds. Q7\ Why do BOD and COD values for the same water sample are always different? Because COD includes both biodegradable and non-biodegradable substances whereas BOD contains only bio-degradable. - COD values are always higher than the BOD values. - COD will generate a higher concentration reading than BOD Generally, COD:BOD ratio 2:1 In textile wastewater COD:BOD ratio 5:1 Q8\ Explain the advantages of COD test compared with BOD test? COD BOD Chemical process by using strong oxidizing Biological process by using aerobic agent. microorganisms. Short test (few hours) Lengthy test (5 days) Measures all organic matter (biodegradable Measures biodegradable organics only and non-biodegradable COD can test wastewater. Wastewater is considered too toxic for BOD test. 31 ‫ ﺗﺒﺪأ ﻣﻦ ﺳﻼﯾﺪ رﻗﻢ‬4 ‫ ﺷﺎﺑﺘﺮ‬COD ‫ذاﻛﺮ أﻣﺜﻠﺔ اﻟـ‬  Chapter 5 *The treatment of wastewater is accomplished by four basic methods or techniques: Compare the water treatment methods among each other. Describe and explain the wastewater treatment process by focusing on the main stages of the treatment process using activated sludge. 1- Physical 2- Mechanical 3- Biological 4- Chemical - Physical methods of treatment include the use of tanks and other structures designed to contain and control the flow of wastewater to promote the removal of contaminants. - Mechanical treatment techniques involve the use of machines, both simple and complex in design and operation. - Biological the action of bacteria and other micro-organisms, which play a vital role in the removal of pollutants which cannot be effectively achieved by other means. - Chemical treatment methods enhance the efficiency of other process operations and provide specialized treatment as a result of their addition at various treatment stages. Q1\ Draw a schematic wastewater treatment process providing primary and secondary treatment using activated sludge? Preliminary treatment will get rid of large debris and heavy inorganic material by screening then grit chamber will remove sands. In Primary settling, 60% - 70% of the suspended solids will settle at the bottom of the tank (called primary sludge) and will be moved to Thickener whereas the remaining water will be moved to aeration tank. to the aeration tank to keep aerobic organisms alive. Where bacteria will feed on organic materials. The bacteria will become bigger in size and will settle at the bottom of secondary settling tank. The settling bacteria (called secondary sludge) will be divided into Activated sludge which will be recycled in Aeration tank and waste sludge which will be moved to the thickener tank. The remaining water in Secondary settling tank will be moved to the chlorine contact tank where chlorine will be added to kill bacteria. Thickener tank will contain primary sludge and waste sludge and will begin the sludge treatment. Thickener, Anaerobic digester and sludge dewatering tanks will reduce the solid waste and the remaining supernatant water will return to the plant influent. *In Primary treatment, oils, fats, and grease are skimmed from the tank surface. Q2\ Describe the collection system of wastewater treatment? The collection system is a series of pipes designed to transport wastewater generated each day. Sewer piping is categorized by the type of flow it transports namely: sanitary, storm and combined sewers. - Gravity flow: pipes are laid with a lope of steep enough to maintain wastewater flow velocity of 0.75 m/s - Collection system must be properly maintained to prevent infiltration, inflow or exfiltration from occurring Q3\ illustrate the preliminary treatment step in wastewater treatment? Preliminary treatment provides the removal of large debris and heavy inorganic material. The removal of these materials protects the treatment plant’s piping and downstream equipment from blockage and/or damage Common form of Q4\ Explain with drawing the floating cover anaerobic digester treatment process? The sludge produced during primary and secondary settling is directed to digester. Digester is large enclosed tank free of molecular oxygen. The duration of digester treatment are typically 15 to 28 days. The digester tank contents are heated to 35 - 37 C to kill bacteria and prevent the formation of a scum blanket. The end products of digestion are stabilized biosolids and supernatant. Supernatant will return to the plant influent. Gas produced during digestion 35% CO2 carbon dioxide and 65% CH4 methane. Q5\ Explain with drawing the activated sludge process? Activated sludge is a process for treating wastewater using aeration and biological floc composed of bacteria. Air is added to the aeration tank to keep aerobic organisms alive. Q6\ what are the chemical treatment in wastewater treatment? 1- The removal of phosphorus by using metal salt. 2- The removal of bacteria by using chlorine. - The most common metal salt in use is ferrous chloride. Q7\ explain the dewatering process with drawing the major solid handling processes? Dewatering is a solid handling process operation. Stabilized biosolids from secondary anaerobic digestion are directed to dewatering to remove excess water. This operation reduces the volume and increases the dryness of the solids for further processing. The removed water is returned to the plant influent. Q8\ what are the composting process in wastewater treatment? Composting process begins with mixing of dewatered cake, amendment material and a recycle of previously composted material. - Amendment (waste wood) TERTIARY TREATMENT Tertiary treatment is the final cleaning process that improves wastewater quality before it is reused, recycled or discharged to the environment. The tertiary treatment removes remaining inorganic compounds, substances, and bacteria. Alum is used to remove additional phosphorus particles and group the remaining solids together. Tiny particles are created called floc because of alum. Filters are backwashed every 24 hours to remove the flocs. Chlorine is removed by adding sodium bisulphite just before discharge. Q9\ Draw a sketch showing the Types of mixer impellers. Q10- Draw a sketch showing the different Rapid mixing devices. ‫اﻟﻤﻄﻠﻮب ﻣﻦ ھﻮ ﺣﻔﻆ اﻷﺳﻤﺎء ﻓﻘﻂ ھﻮ راح ﯾﻌﻄﯿﻚ اﻟﺮﺳﻤﺔ واﻧﺖ ﺗﻜﺘﺐ اﺳﻤﮭﺎ‬ Q11\ Draw a sketch showing the horizontal flow clarifier and vertical (upflow clarifier). (a) HORIZONTAL FLOW CLARIFIER  (b) VERTICAL OR UPFLOW CLARIFIER Q12\ Explain the function of different parts of sedimentation basin. Particles that will settle within a reasonable time can be removed in a sedimentation basin or clarifier  Geometric configuration: Circular OR rectangular  Flow pattern: radial, upward  Parts of a sedimentation basin or clarifier – functions: Inlet zone: To distribute the flow and suspended particles to the settling zone. It consists of series of inlet pipes and baffles. Settling zone: settling of particles takes place. Sludge zone: used to store sludge prior to disposal Outlet zone: To remove the settled water from the water