Lecture 1 wastewater treatment introduction.pptx

wastewater

1. “ 202 4 -202 5 ” Instructor :Dr / Marwa Maher Lec 1 Wastewater Treatment Chemical Engineering Department CHE 371 Lecture 1

2. Hours : 2 Lec. - 2 Tut. Course Aims: The course aims to develop a higher level of expertise, principally in the areas of water and wastewater treatment methodology, and the design of wastewater treatment facilities Course Objectives : At the end of this course, student should be able to : Justify the physical and chemical processes involved in the treatment of surface water i ncluding detailed theories of sedimentation Design a typical water treatment system for a small community Describe wastewater characterization Analyze the principles and biological processes involved in advanced biological wastewater treatment of a typical urban wastewater having organic and nutrient contaminants Design the components of wastewater treatment systems tailored to cater for different wastewater compositions Evaluate the options available for disposal of treated wastewater and sludge 2

3. Assessment Schedule and Grades Distribution: Assessment Method Mark Percentage Week Final Examination (written) 30 60 % 16 th Mid term written Examination1 (Term Work) 10 20 % 8 th Quizzes 10 20 % According the schedule Total 50 100% 3

4. Source and Characteristics of Industrial Wastewaters - Wastewater treatment processes: pre - and primary treatment (equalization, neutralization, sedimentation, oil separation, flotation) - Coagulation and precipitation - Aeration and mass transfer - Principles of biological oxidation: Mechanisms of organic removal by bio - oxidation, Considerations, Nitrification and Denitrification - Development of process design parameters - Biological wastewater treatment processes: Lagoons and stabilization basins, Aerated lagoons, Activated sludge processes, Trickling filtration, Rotating biological contactors, Anaerobic decomposition - Adsorption: theory of adsorption, properties of activated carbon, the Powdered Activated Carbon Treatment (PACT) process - Ion exchange - Chemical oxidation- Sludge handling and disposal - Miscellaneous treatment processes: Land treatment, Deep - well disposal, Membrane processes, Phosphorous removal, Filtration. Dr.Safaa rushdy 4

5. Textbook: W. Wesley Eckenfelder, Jr., Principles of Water Quality Management, CBI Publishing, 1980. A. P. Sincero and G. A. Sincero, hysical - Chemical Treatment of Water & Wastewater, IWA publishing, CRC Press, 2003. Frank R. Spellman, Handbook of Water & Wastewat Treatment Plant Operations Lewis Publishers, CRC Press Company, 2003. References: W. Wesley Eckenfelder, Jr., Industrial Water Pollution Control, Mc Graw - Hill Companies Inc., 3rd. Ed., 2000. Assessment: Final Exam: 60% , Quizzes: 20% , Mid Term Exam: 20% , Dr.Safaa rushdy 5

6. "Wastewater is simply that part of the water supply to the community or to the industry which has been used for different purposes and has been mixed with solids either suspended or dissolved." Wastewater is 99.9% water and 0.1% solids. The main task in treating the wastewater is simply to remove most or all of this 0.1% of solids. Wastewater = clean water supply + solids Wastewater treatment is simply the separation of solids from water. Clean water = Wastewater– Solids 1.Introduction

7. Wastewater Characteristics Physical Chemical Biological

8. Physical characteristics Physical properties are subject to natural forces making it easier to measure & determine their values & effects. Physical properties of significance include: concentration of solids, turbidity, taste, odor, color, temperature, electrical conductivity, salinity, density, standard volume, viscosity, surface tension, moisture content, humidity, radiation and dissolved oxygen.

9. 9 Temperature Temperature of water & wastewater may change due to climatic effects, hot discharge (thermal pollution) & industrial discharges. Increase in temperature affect performance purification or treatment units . reduces concentration of dissolved oxygen . accelerating rates of chemical & biochemical reactions . reduce solubility of gases . increase rate of corrosion of materials . increase toxicity of dissolved elements . increase undesired growth, and increase problems of taste & odor.

10. Conductivity Conductivity denotes intensity of an aqueous solution to carry an electric current. This ability is influenced by: concentration, type mobility, valence & relative concentration of ions; & temperature. Generally, solutions of most inorganic acids, bases & salts are relatively good conductors. Electrical conductivity is an important indicator of water quality and can be used for: ✅ Monitoring water salinity : Water with high conductivity contains a large amount of dissolved salts . ✅ Determining pollution levels in wastewater : Wastewater contains numerous ions, which increase electrical conductivity compared to freshwater. ✅ Monitoring water quality in treatment plants : Conductivity measurements can be used to ensure that water has been properly treated and is free from harmful dissolved substances .

11. What is Total Dissolved Solids (TDS)? ✅ Definition: TDS represents the total amount of dissolved substances (salts, minerals, metals, organic compounds) in water. ✅ Unit: Measured in milligrams per liter (mg/L) or parts per million (ppm). ✅ Formula for Estimation: TDS (mg/L) ≈ EC (mS/cm ( millisiemens per cm ) × Conversion

12. 10 Density Density is the mass of a substance per unit volume or in a qualitative manner it is the measure of the relative "heaviness" of objects with a constant volume. Density is temperature dependent. ρ = m/V (1) where: ρ = Density of the fluid, kg/m 3 . m = Mass, kg. V = Volume, m 3 . Specific volume Specific volume is the volume per unit mass, i.e. it is the reciprocal of the density. κ = 1/ρ (2) Where: κ = Specific volume of the fluid, m3 /kg. ρ = Density of the fluid, kg/m 3 .

13. Specific weight Specific weight is the weight of unit volume. γ = m*g/V = ρ*g Where: γ = Specific weight, N/m 3 . m = Mass, kg. g = Gravitational acceleration, m/s2. V = Volume, m 3 . ρ = Density of the fluid, kg/m 3 . Specific gravity Specific gravity is the ratio of the density of fluid to the density of water at some specified temperature. Viscosity of a fluid is a measure of its resistance to shear or angular deformation. Viscosity is the property that relates the applied forces to 11 the rates of deformation of the fluid. (3)

14. 14 Bulk Modulus (Bulk Modulus of Elasticity) (is a property that is used to evaluate the degree of compressibility. Large values of bulk modulus indicates fluid is relatively incompressible (i.e. a large pressure change is needed to create a small change in volume). Where: Ev = Bulk modulus, N*m - 2 . dP = Differential change in pressure, Pa. dV = Differential change in volume, m 3 . V = Volume, m 3 . ρ = Density of fluid, kg/m 3 .

15. 15 Radioactivity Radioactivity is property of unstable atoms. It arises from the spontaneous breaking up of certain heavy atoms into atoms of other kinds which might themselves be radioactive. Radioactivity continues forming a transformation series. The disintegration results in emission of alpha particles, beta particles, & gamma rays. Each radioactive substance is characterized by a certain time known as its half- life period. The half- life period is the time taken for half the atoms in any given sample of the substance to decay. Half- life periods are different for each element. Amounts of radiation can be measured in curies, rems, millirems &rads.

16. Dr.Safa Curie is intensity of a sample of radioactive material in terms of atoms of the material that decay each second, or is the number of disintegrations occurring per second in one gram of pure radium. This rate (37 billion atoms per second for one gram of radium) is the basis of this measurement. Rem : is a measurement of effects of radiation on the body. Rad is the unit of measure for physical absorption of radiation.