Waste water treatment: Review

Lectures Introduction Review Quality and treatment Treatment Reactors Physical Chemical Biological Equalization Precipitation Activated sludge Filtration Sorption Trickling filter Settling Ion exchange Desalination Disinfection Coagulation CIVL375-Maraqa REVIEW CIVL375-Maraqa Units of Measurement Basic units and conversion factors Quantity SI Units SI Symbol Length Meter m 3.2808 ft Mass Kilogram kg 2.2046 lb Temperature Celsius o 1.8(oC)+32 o Area Square meter m2 10.7639 ft2 Volume Cubic meter m3 35.3147 ft3 Energy Kilojoule kJ 0.9478 Btu Power Watt W 3.4121 Btu/hr Velocity Meter/sec m/s 2.2369 mi/hr Flow rate Meter3/sec m3/s 35.3147 ft3/s Density Kilogram/meter3 kg/m3 0.06243 lb/ft3 C Conversion Factor Gallon is a unit of volume = 3.785 liters You may download the program convert.exe for future use http://www.teachers.ash.org.au/geparker/how_to_use_convert.htm USCS Units F Prefixes CIVL375-Maraqa Quantity Prefix Symbol 10-9 nano n 10-6 micro 10-3 milli µ m 10-2 centi c 10-1 deci d 10 deka da 102 hector h 103 kilo k 106 mega M 109 giga G Periodic Table Source: http://www.webelements.com/ Concentration Solute + contaminant Solvent pure water = Solution water or wastewater to be treated Units of Concentration • mg/L = part per million (ppm) for dilute solution • ug/L= part per billion (ppb) • Molarity (mol/L); number of moles= mass/ atomic or molecular weight • Normality (eq/L); number of equivalents= mass/ equivalent weight • mg/L as CaCO3 Concentration of X (mg / L) × 50 ( mg CaCO3 / meq) mg of X as CaCO3 = L Eq wt of X ( mg / meq) • Percent by mass Example: Gulf sea water contains about 4% total dissolved solids (TDS) What is the concentration of TDS in mg/l Solution: 4% means g TDS/ 100 g water Since 1000 g water is liter, then 100 g water is 0.1 liter 4% = 4000 mg TDS/ 0.1 liter water = 40,000 mg/ liter CIVL375-Maraqa Solids Solids in water Suspended (turbidity) Dissolved (mainly salinity) Filtration Solids in water Volatile (organic) Fixed (inorganic: salts and metals) Combustion at 550 oC CIVL375-Maraqa Microorganisms Microorganism Size (um) Viruses 0.02-0.3 Bacteria 0.1-10 Some are pathogenic Cholera, typhoid Algae 1-100 Non pathogenic Fungi Few umseveral cm Protozoa 10-300 CIVL375-Maraqa Disease All pathogenic AIDS, hepatitis, mad cow Many are nonpathogenic Some are pathogenic Amebic dysentery, malaria Test for Pathogens Total coliform coliform Total 35 oC Fecal Fecal 44.5 oC Nonfecal Nonfecal  Membrane Filter Technique  Multiple-Tube Fermentation Technique Note: Pathogenic means disease-causing Also note that all coliforms are non pathogenic except E Coli, but they are good indicator of the presence of pathogens CIVL375-Maraqa Water pollution pollution Water Physical Physical Radiological Radiological •Thermal •Solids Chemical Chemical Biological Biological •Radio-isotopes •Hardness •Pathogens •Heavy metals •Nutrients •Pesticides •Oxygen demanding waste •Volatile organic compounds (VOCs) CIVL375-Maraqa Treatment Reactors • Batch Reactors • Completely Stirred Tank Reactors (CSTR) • Plug-Flow Reactors • Dispersed Plug-Flow Reactors • Packed bed Reactors • Fluidized Packed bed Reactors CIVL375-Maraqa Reactions Transform Chemical Transfer Biological Volatilization Hydrolysis Aerobic degradation Radioactive decay Anaerobic degradation Sorption Photodegradation Combustion Oxidation-reduction CIVL375-Maraqa Ion exchange Bio uptake Sedimentation Industry Wells Pollution Control Industry Pretreatment Wells Stream Lake or Sea WTP To people Sanitary sewer Homes WWTP Discharge or reuse Examples of WTPs: Al Fujairah, Al Taweela, and Umm Al Nar Examples of WWTPs: Zakher, Al Mafraq, Jebel Ali, and Al Aweer CIVL375-Maraqa CIVL270 Needed Material     Chemistry and microbiology Mass balance Water pollution Pollution control CIVL375-Maraqa [...].. .Water pollution pollution Water Physical Physical Radiological Radiological •Thermal •Solids Chemical Chemical Biological Biological •Radio-isotopes •Hardness •Pathogens •Heavy metals •Nutrients •Pesticides •Oxygen demanding waste •Volatile organic compounds (VOCs) CIVL375-Maraqa Treatment Reactors • Batch Reactors... Examples of WTPs: Al Fujairah, Al Taweela, and Umm Al Nar Examples of WWTPs: Zakher, Al Mafraq, Jebel Ali, and Al Aweer CIVL375-Maraqa CIVL270 Needed Material     Chemistry and microbiology Mass balance Water pollution Pollution control CIVL375-Maraqa