Static mixers are an attractive alternative for the mixing of chemicals in water treatment plants. The attraction comes from the fact that static mixers do not require an external input of energy and do not have moving parts. Static mixers consist of mixing elements fixed on the inside of a pipe of channel. The elements do not move. Chemicals, added just upstream of the mixers, mix with the bulk fluid because of the complex, three-dimensional fluid motion generated by the elements. The goal of this project is to explore the use of static mixers in two of the key processes in drinking water treatment: for the mixing of coagulants for destabilization and the mixing of disinfectants for the inactivation of Cryptosporidium parvum oocysts in disinfection. The role of mixing in both of these processes is not well understood. But for each process experimental and theoretical evidence suggests that, at least in some circumstances, the mixing environment provided when chemicals are introduced into the flow will affect the resulting destabilization or inactivation.

Among the known disinfectants, ozone has been demonstrated to be very effective in inactivating protozoans. Current and proposed regulations impose additional treatment requirements for Cryptosporidium parvum. These regulatory trends tend to place more stringent performance demands on disinfection systems and have therefore increased the need for improvements in the design. The static mixer offers one alternative method for improving the efficiency of the dissolution of ozone and optimizing its use in the disinfection process.The overall objective of this research was to quantify the potential benefits of ozone application through the use of static mixers in terms of increased transfer efficiency, disinfection capacity, and enhanced chemical reactions at laboratory-, pilot-, and full-scale systems. Specific goals were to identify and quantify the effect of several water quality parameters and environmental/engineered factors on the disinfection capacity of the ozone-static mixer system and assess bromate formation under optimum conditions for microbial inactivation.Originally published by AwwaRF for its subscribers in 2003 This publication can also be purchased and downloaded via Pay Per View on Water Intelligence Online - click on the Pay Per View icon below

This manual is a source document for utilities that are considering a coagulant changeover. It is intended to provide an appreciation of what must be considered for a successful changeover based on the input of U.S. and Canadian utilities (Chapters 1 and 6). New regulatory requirements will likely have the broadest and most substantial impact on primary coagulant use (Chapter 3). The Interim Enhanced Surface Water Treatment Rule (IESWTR) and Stage 1 Disinfectant and Disinfection Byproducts Rule (Stage 1 DBPR) will make finished water requirements more stringent to address microbial removal and the impacts of disinfection. Enhanced Coagulation and/or other operational and treatment practices will be used to achieve these requirements. The science of coagulation (Chapter 4) requires a special focus to address the intricacies of coagulation chemistry. The manual provides a step-by-step methodology to conduct a coagulant changeover using a detailed protocol (Chapter 5) -- background, executive summary.

Carefully designed to balance coverage of theoretical and practical principles, Fundamentals of Water Treatment Unit Processes delineates the principles that support practice, using the unit processes approach as the organizing concept. The author covers principles common to any kind of water treatment, for example, drinking water, municipal wastew

The unit process approach, common in the field of chemical engineering, was introduced about 1962 to the field of environmental engineering. An understanding of unit processes is the foundation for continued learning and for designing treatment systems. The time is ripe for a new textbook that delineates the role of unit process principles in environmental engineering. Suitable for a two-semester course, Water Treatment Unit Processes: Physical and Chemical provides the grounding in the underlying principles of each unit process that students need in order to link theory to practice. Bridging the gap between scientific principles and engineering practice, the book covers approaches that are common to all unit processes as well as principles that characterize each unit process. Integrating theory into algorithms for practice, Professor Hendricks emphasizes the fundamentals, using simple explanations and avoiding models that are too complex mathematically, allowing students to assimilate principles without getting sidelined by excess calculations. Applications of unit processes principles are illustrated by example problems in each chapter. Student problems are provided at the end of each chapter; the solutions manual can be downloaded from the CRC Press Web site. Excel spreadsheets are integrated into the text as tables designated by a "CD" prefix. Certain spreadsheets illustrate the idea of "scenarios" that emphasize the idea that design solutions depend upon assumptions and the interactions between design variables. The spreadsheets can be downloaded from the CRC web site. The book has been designed so that each unit process topic is self-contained, with sidebars and examples throughout the text. Each chapter has subheadings, so that students can scan the pages and identify important topics with little effort. Problems, references, and a glossary are found at the end of each chapter. Most chapters contain downloadable Excel spreadsheets integrated into the text and appendices with additional information. Appendices at the end of the book provide useful reference material on various topics that support the text. This design allows students at different levels to easily navigate through the book and professors to assign pertinent sections in the order they prefer. The book gives your students an understanding of the broader aspects of one of the core areas of the environmental engineering curriculum and knowledge important for the design of treatment systems.

Advances in Industrial Mixing is a companion volume and update to the Handbook of Industrial Mixing. The second volume fills in gaps for a number of industries that were not covered in the first edition. Significant changes in five of the fundamental areas are covered in entirely updated or new chapters. The original text is provided as a searchable pdf file on the accompanying USB. This book explains industrial mixers and mixing problems clearly and concisely. Gives practical insights by the top professionals in the field, combining industrial design standards with fundamental insight. Details applications in 14 key industries. Six of these are new since the first edition. Provides the professional with information he/she did not receive in school. Five completely rewritten chapters on mixing fundamentals where significant advances have happened since the first edition and seven concise update chapters which summarize critical technical information.