The activated sludge process : methods and recent developments

In this collection, the authors report on the pretreatment methods for waste activated sludge based on pulsed electric field and corona discharge techniques. The effects of pulse magnitude, frequency, temperature and pretreatment time are demonstrated on the basis of cell membrane electroporation. The influence of voltage polarity, frequency, magnitude, treating time and temperature has also been demonstrated. A description of fundamental techniques in molecular biology for the analysis of the microbiota of activated sludge is provided. Activated sludge is a heterogeneous system of organisms, organic and inorganic material, and therefore giving a specific protocol for each molecular technique would be imprudent. The authors go on to discuss the Monod model, which provides a functional relationship between specific growth rate and substrate concentration in the bulk. Important research efforts dedicated to adequate use of the Monod model are presented, consolidating knowledge from activated sludge and biofilm modelling, identifying misdirections, and setting parameters for further research. In one study, different microwave power outputs and times were optimised for sludge solubilisation without evaporation loss in waste activated sludge from two different sources. The variable effects of pre-treatments on extracellular polymeric substances fraction, cellular oxidative stress and solubilisation of both sludges were evaluated to understand the impact of sludge complexity. The penultimate chapter examines how toxic carbon sources can cause higher residual effluent dissolved organic carbon than easily biodegraded carbon sources in the activated sludge process. Based on the variations of chemical components of activated sludge, mainly intracellular storage materials, extracellular polymeric substances and soluble microbial products, the performance and mechanism of toxic carbon on the activated sludge process can be clarified. The purpose of the final study is to research the supplementation of different concentrations of substrate on the degradation rate of xenobiotics, and to determine the optimal concentrations of auxiliary substrates that are most beneficial. The results show that sugar and peptone can affect 2,4-D degradation rate by several different degrees at different concentrations. Contents Preface Chapter 1 Pretreatment of Waste Activated Sludge Based on Pulsed Electric Field and Corona Discharge Techniques Abstract 1. Introduction 2. Experimental Setup 2.1. High Voltage Pulse Generator Design and Test Vessel for the PEF Pretreatment 2.2. Electrode Arrangement and Power Sources Used for Corona Discharge Pretreatment 2.3. Characterization of the WAS Pretreatment Performance 2.3.1. Coloring by Trypan Blue Solution 2.3.2. Measurement of Released Organic Matter Content 2.3.3. Other Characterization Methods for WAS Pretreatment 2.4. Test Procedure for the WAS Pretreatment 3. Test Results and Discussion 3.1. Pretreatment of the WAS with the PEF 3.2. Pretreatment of the WAS with the Corona Discharge Method 3.2.1. Comparison of WAS Pretreatment Performance between DC and High Frequency AC Voltages Induced Corona Discharge 3.2.2. Effects of Treating Temperature and Treating Time on the WAS Pretreatment Performance with DC Corona Discharge 3.3. WAS Pretreatment with PEF-Corona Discharge Combined Method Conclusion Acknowledgments References Biographical Sketches Chapter 2 Molecular Methods to Study the Microbial Phenomena of Bulking, Foaming, and Zoogleal Bulking in Activated Sludge Abstract Introduction Methods Polymerase Chain Reaction (PCR) PCR and Cloning Fluorescence In Situ Hybridization (FISH) High-Throughput Sequencing References Chapter 3 A Macrokinetic Use of the Monod Model in Biological Wastewater Treatment Abstract Outline The Monod Model and Its Use in Biological Wastewater Treatment Modelling A Unified View of Growth Processes in Biological Wastewater Treatment Why Think and Model Biofilms in Layers? A Quality Assessment of Zero-Dimensional Models for Biological Wastewater Treatment Future Directions References Chapter 4 The Effect of Combined Microwave and Hydrogen Peroxide Pretreatment on Sludge Characteristics and Oxidation Status of Waste Activated Sludge Abstract Introduction Materials and Methods Waste Activated Sludge Samples Analytical Methods Reactive Oxygen Species Quantification Microwave Treatment Oxidant Treatment EPS Fraction Extraction Results and Discussion Effect of Microwave Power Intensity, Density and Time on Sludge Solubilisation Effect of Combined Pre-Treatment in Sludge Solubilisation Effect of Pre-Treatment in Biopolymer Solubilisation Effect of Pre-Treatment on Oxidative Stress of Sludge Effect of Pre-Treatment in Settleability Conclusion Acknowledgments References Chapter 5 The Effect of Toxic Carbon Sources on the Reaction Process of Activated Sludge Abstract 1. Introduction 2. Components of EPS, SMP and XSTO for Activated Sludge 2.1. Extracellular Polymeric Substances (EPS) 2.2. Soluble Microbial Products (SMP) 2.3. Intracellular Storage Products (XSTO) 3. Analyses of EPS, SMP and XSTO 3.1. EPS Measurements 3.2. SMP Measurements 3.3. XSTO Measurements 4. SMP Production Characteristics on Toxic Conditions 5. Variations of EPS, SMP and XSTO with Toxic/Nontoxic Carbons 5.1. Experimental Study 5.2. Modeling Reaction of the Activated Sludge 5.3. The Effect of Toxic Carbon Source on the Reaction of Activated Sludge References Chapter 6 The Effects of Combined Growth of Biogenic and Xenobiotic Substrates on Degradation of Xenobiotic by Activated Sludge Abstract 1. Introduction 2. Materials and Methods 2.1. Suspended Solid (SS) Measurements 2.2. Experimental Method to Obtain Acclimated Activated Sludge 2.3. Experimental Methods with (Sugar) Sucrose and Peptone 2.4. 2,4-D Degradation Rate Calculation 3. Results and Discussion 3.1. Effects of Different Sugar Concentrations on 2,4-D Degradation Rate 3.2. Effects of Different Peptone Concentrations on 2,4-D Degradation Rate 3.3. Effects of Combined Auxiliary Substrates on 2,4-D Degradation Rate Conclusion Acknowledgments References Index Blank Page Pretreatment of Waste Activated Sludge Based on Pulsed Electric Field and Corona Discharge Techniques / Yu Gao, Yong Liu, and Tao Han -- Molecular Methods to Study the Microbial Phenomena of Bulking, Foaming, and Zoogleal Bulking in Activated Sludge / María Isabel Neria-González -- A Macrokinetic Use of the Monod Model in Biological Wastewater Treatment / Mario Plattes -- The Effect of Combined Microwave and Hydrogen Peroxide Pretreatment on Sludge Characteristics and Oxidation Status of Waste Activated Sludge / Herald Wilson Ambrose, Ligy Philip, Tushar Kanti Sen and G. K. Suraishkumar -- The Effect of Toxic Carbon Sources on the Reaction Process of Activated Sludge / Changyong Wu, Min Xu and Yuexi Zhou -- The Effects of Combined Growth of Biogenic and Xenobiotic Substrates on Degradation of Xenobiotic by Activated Sludge / Nguyen Phuc Thien, Le Quoc Tuan, and Doan Quang Tri