Sustainable Wastewater Treatment and Engineering Introduction and history Current practice Emerging issues Future directions Regulatory requirements References Reaction Kinetics and Chemical Reactors Reaction kinetics How to find the order of a reaction Zero order reaction First order reaction Second order reaction Reactors Batch reactor Continuous-flow stirred tank reactor Reactors in series Semibatch or semiflow reactors Problems References Wastewater Microbiology Introduction Bacteria Archaea Protozoa Algae Fungi Virus Problems References Natural Purification Processes Impurities in water Dilution Sedimentation Microbial degradation Measurement of organic matter Dissolved oxygen balance Problems References Wastewater Treatment Fundamentals Introduction Sources of wastewater Wastewater constituents Wastewater treatment methods Levels of wastewater treatment Residuals and biosolids management Flow diagrams of treatment options Types of biological treatment processes Problems References Preliminary Treatment Introduction Screens Shredder/grinder Grit chamber Problems References Primary Treatment Introduction Types of settling/sedimentation Type I sedimentation Type II sedimentation Primary sedimentation Chemically enhanced primary treatment Problems References Secondary Treatment: Suspended Growth Processes Introduction Microbial growth kinetics Activated sludge process (for BOD removal) Modeling suspended growth processes Types of suspended growth processes Stabilization ponds and lagoons Problems References Secondary Treatment: Attached Growth and Combined Processes Introduction System microbiology and biofilms Important media characteristics Loading rates Stone media trickling filter Biotower Rotating biological contactor Hybrid processes Combined processes Problems References Secondary Clarification Introduction Secondary clarifier for attached growth process Secondary clarifier for suspended growth process Problems References Anaerobic Wastewater Treatment Introduction Process chemistry and microbiology Methanogenic bacteria Sulfate-reducing bacteria Environmental requirements and toxicity Methane gas production Anaerobic growth kinetics Anaerobic suspended growth processes Anaerobic attached growth processes Hybrid processes Problems References Solids Processing and Disposal Introduction Characteristics of municipal sludge Sludge quantification Sludge thickening Sludge stabilization Conditioning of biosolids Biosolids dewatering Disposal of biosolids Biosolids disposal regulations in the United States Problems References Advanced Treatment Processes Introduction Nitrogen removal Phosphorus removal Solids removal Problems References Appendix Index
Dr. Rumana Riffat is a professor in the Civil and Environmental Engineering Department at George Washington University in Washington, D.C. Her research interests are in wastewater treatment, specifically anaerobic treatment of wastewater and biosolids, as well as nutrient removal. She and her research group have conducted extensive research on processes to further reduce pathogens, such as dual digestion, temperature-phased digestion, and various pretreatment options. Her nutrient removal research has focused on determination of kinetics and evaluation of various external carbon sources for denitrification. Dr. Riffat received the Distinguished Teacher Award from the School of Engineering and Applied Science of George Washington University in 2011 and the George Bradley Gascoigne Wastewater Treatment Plant Operational Improvement Medal of the Water Environment Federation (WEF) in 2010. She is a member of several professional organizations, including WEF and the ASCE, and is a registered professional engineer of the District of Columbia.