Anaerobic Digestion Processes

This book presents new application processes in the context of anaerobic digestion (AD), such as phosphorus recovery, microbial fuel cells (MFCs), and seaweed digestion. In addition, it introduces a new technique for the modeling and optimization of AD processes. Chapters 1 and 2 review AD as a technique for converting a range of organic wastes into biogas, while Chapter 3 discusses the recovery of phosphorus from anaerobically digested liquor. Chapters 4 and 5 focus on new techniques for modeling and optimizing AD. Chapters 6 and 7 then describe the state of the art in AD effluent treatment. The book’s final three chapters focus on more recent developments, including microbial fuel cells (MFCs) (Chapter 8), seaweed production (Chapter 9), and enzyme technologies (Chapter 10).

There have been many significant microbiological, biochemical and technological advances made in the understanding and implementation of anaerobic digestion processes with respect to industrial and domestic wastewater treatment. Elucida tion of the mechanisms of anaerobic degradation has permitted a greater control over the biological parameters of waste conversion and the technical advances achieved have reduced the time and land area requirements and increased the cost-effectiveness and efficiency of the various processes presently in use. By product recovery in the form of utilisable methane gas has become increasingly feasible, while the development of new and superior anaerobic reactor designs with increased tolerance to toxic and shock loadings of concentrated effiuents has established a potential for treating many extremely recalcitrant industrial wastestreams. The major anaerobic bioreactor systems and their applications and limitations are examined here, together with microbiological and biochemical aspects of anaerobic wastewater treatment processes. London, June 1986 S. M. Stronach T. Rudd J. N. Lester v Table of Contents 1 The Biochemistry of Anaerobic Digestion 1 1. 1 Kinetics of Substrate Utilisation and Bacterial Growth 3 1. 1. 1 COD Fluxes and Mean Carbon Oxidation State 3 1. 1. 2 Bacterial Growth and Biokinetics 4 1. 1. 2. 1 Growth and Single Substrate Kinetics 4 1. 1. 2. 2 Multisubstrate Systems . 8 1. 2 Kinetics and Biochemistry of Hydrolysis 8 1. 3 Kinetics and Biochemistry of Fermentation and J1-0xidation . 11 1.

Anaerobic digestion is a biochemical degradation process that converts complex organic material, such as animal manure, into methane and other byproducts. Part of the author's Wastewater Microbiology series, Microbiology of Anareboic Digesters eschews technical jargon to deliver a practical, how-to guide for wastewater plant operators.

Hundreds of million tonnes of agricultural and food waste are produced each year around the world, most of which is just that, waste. Anaerobic digestion, biogas and the heat and electricity that can be produced from it is still a nascent industry in many countries, yet the benefits of AD spread throughout the community: Gives good financial returns to farmers and eco-entrepreneurs. Helps community leaders meet various policies and legislative targets. Offers an environmentally sensitive waste disposal option. Provides a local heat and power supply, & creates employment opportunities Reduces greenhouse gas emissions, as well as providing an organic fertilizer. Although the process of AD itself is relatively simple there are several system options available to meet the demands of different feedstocks. This book describes, in simple, easy to read language the five common systems of AD; how they work, the impact of scale, the basic requirements, the costs and financial implications, and how to get involved in this rapidly growing green industry.

Anaerobic digestion (AD) is a biological process that happens naturally when bacteria breaks down organic matter in environments with little or no oxygen. It is effectively a controlled and enclosed version of the anaerobic breakdown of organic waste in landfills which release methane. In this book, the authors present current research in the study of the processes, products and application of anaerobic activity. Topics discussed include the anaerobic treatment of wastewater; a scientific review of the agronomic, environmental and social benefits of anaerobic digestion and the microbial aspects of anaerobic digestion for biogas production.

The IWA Task Group for Mathematical Modelling of Anaerobic Digestion Processes was created with the aim to produce a generic model and common platform for dynamic simulations of a variety of anaerobic processes. This book presents the outcome of this undertaking and is the result of four years collaborative work by a number of international experts from various fields of anaerobic process technology. The purpose of this approach is to provide a unified basis for anaerobic digestion modelling. It is hoped this will promote increased application of modelling and simulation as a tool for research, design, operation and optimisation of anaerobic processes worldwide. This model was developed on the basis of the extensive but often disparate work in modelling and simulation of anaerobic digestion systems over the last twenty years. In developing ADM1, the Task Group have tried to establish common nomenclature, units and model structure, consistent with existing anaerobic modelling literature and the popular activated sludge models (See Activated Sludge Models ASM1, ASM2, ASM2d and ASM3, IWA Publishing, 2000, ISBN: 1900222248). As such, it is intended to promote widespread application of simulation from domestic (wastewater and sludge) treatment systems to specialised industrial applications. Outputs from the model include common process variables such gas flow and composition, pH, separate organic acids, and ammonium. The structure has been devised to encourage specific extensions or modifications where required, but still maintain a common platform. During development the model has been successfully tested on a range of systems from full-scale waste sludge digestion to laboratory-scale thermophilic high-rate UASB reactors. The model structure is presented in a readily applicable matrix format for implementation in many available differential equation solvers. It is expected that the model will be available as part of commercial wastewater simulation packages. ADM1 will be a valuable information source for practising engineers working in water treatment (both domestic and industrial) as well as academic researchers and students in Environmental Engineering and Science, Civil and Sanitary Engineering, Biotechnology, and Chemical and Process Engineering departments. Contents Introduction Nomenclature, State Variables and Expressions Biochemical Processes Physicochemical Processes Model Implementation in a Single Stage CSTR Suggested Biochemical Parameter Values, Sensitivity and Estimation Conclusions References Appendix A: Review of Parameters Appendix B: Supplementary Matrix Information Appendix C: Integration with the ASM Appendix D: Estimating Stoichiometric Coefficients for Fermentation Scientific & Technical Report No.13

Biogas Production covers the most cutting-edge pretreatment processes being used and studied today for the production of biogas. As an increasingly important piece of the "energy pie," biogas and other biofuels are being used more and more around the world in every conceivable area of industry and could be a partial answer to the energy problem and the elimination of global warming. This book will highlight the recent advances in the pretreatment and value addition of lignocellulosic wastes (LCW) with the main focus on domestic and agro-industrial residues. Mechanical, physical, and biological treatment systems are brought into perspective. The main value-added products from lignocellulosic wastes are summarized in a manner that pinpoints the most recent trends and the future directions. Physico-chemical and biological treatment systems seem to be the most favored options while biofuels, biodegradable composites, and biosorbents production paint a bright picture of the current and future bio-based products. Engineered microbes seem to tackle the problem of bioconversion of substrates that are otherwise nonconvertible by conventional wild strains. Although the main challenge facing LCW utilization is the high costs involved in treatment and production processes, some recent affordable processes with promising results have been proposed. Future trends are being directed to nanobiotechnology and genetic engineering for improved processes and products.