ABSTRACT
Ultrasound (US) has been used since its discovery at the beginning of twentieth century for a variety of purposes in diverse areas such as chemical synthesis, medicine, and engineering processing. Besides considering its wide-ranging use and the recent developments, it is also necessary to consider US as a relatively new scienti›c ›eld once there are increasing developments in the area of comprehension of ultrasonic effect and its characteristics. Once the great potential of US has been
Introduction .................................................................................................................................... 535 Food Processing and Preservation ................................................................................................. 537
Effect on Living Cells ............................................................................................................... 537 Drying and Evaporation ............................................................................................................ 539 Emulsi›cation and Mixing ........................................................................................................540 Crystallization and Freezing ..................................................................................................... 541 Other Applications .................................................................................................................... 542
Applications in Biotechnology ...................................................................................................... 542 Microbial Cell Disruption ......................................................................................................... 543 Gene Transfer ............................................................................................................................ 543 Biosensors ................................................................................................................................. 545
Synthesis ........................................................................................................................................546 Textile Industry .............................................................................................................................. 549 Extraction ....................................................................................................................................... 551 Sonocrystallization ......................................................................................................................... 553 Metal and Plastic Welding ............................................................................................................. 562 Crude Oil Industry ......................................................................................................................... 563 Other Processes: Filtration, Separation, and Cleaning ................................................................... 565 Environmental Remediation Using Ultrasound ............................................................................. 567
Water and Wastewater Treatment .............................................................................................. 567 Treatment of Biological and Chemical Contaminants in Water ................................................ 568 Soil and Sediments Remediation .............................................................................................. 571
Soil Washing ......................................................................................................................... 571 Air ......................................................................................................................................... 572
Final Considerations ...................................................................................................................... 572 References ...................................................................................................................................... 573
recognized for a variety of industrial chemical processes, new developments for large-scale processing have been proposed. In fact, acoustic cavitation is the key point for sonochemical processes, and the ability to increase or limit this effect is one of the main challenges for industrial applications of US. In spite of the fact that US has been extensively explored in laboratory scale, consolidated industrial applications are not so numerous (Thompson and Doraiswamy, 1999; Mason, 2000, 2003; Cravotto and Cintas, 2006). In addition, it is important to point out that when an industrial application is in progress it is generally not available in literature due to technological challenges and the market value for process developments. The optimization and design of sonochemical apparatus for largescale applications are continuously in advancement. There is an extensive research for the development of new systems and large-scale applications have been developed using different designs with several transducers. In spite of the extensive effort on this issue, there are only relatively few examples of US applications in industrial process. The main causes lie in the complicated design of ef›cient reactors making dif›cult to reproduce the same conditions developed in laboratory scale (Cintas et al., 2010).
