Recent Patents on Chemical Engineering, 2008, 1, 17-26 17 1874-4788/08 $100.00+.00 © 2008 Bentham Science Publishers Ltd. New Technologies for Water and Wastewater Treatment: A Survey of Recent Patents Berrin Tansel* Florida International University, Civil and Environmental Engineering Department, Engineering Center 3600, Miami, Florida 33174, USA Received: July 31, 2007; Accepted: September 19, 2007; Revised: November 12, 2007 Abstract: The concern over increasing needs for drinking water and awareness for development of systems to improve water quality both for drinking purposes and for effluents from wastewater treatment and industrial facilities have provided incentives to develop new technologies and improve performance of existing technologies. In this paper, the patents on treatment of water and wastewater approved during the period from 1999 to 2007 were reviewed. The patents surveyed were classified into two groups as technologies for water purification systems for drinking water, and technologies for treatment of wastewater. An assessment of the current and future outlook for development of new technologies, methods of treatment, equipment and instruments which can be used for water and wastewater treatment applications are presented. Keywords: Water treatment, water filtration, ultrapure water, wastewater treatment, ion exchange, disinfection, sorption, membrane filtration, nanofiltration, wastewater. 1. INTRODUCTION Water is an essential substance for living systems as it allows the transport of nutrients and waste products in living systems. Research shows a clear correlation between diseases and the amount and types of fluids consumed, health-promoting properties of nutrients which can be added to water, optimal intake levels, and consumption patterns. Although three quarters of the Earth’s surface is covered with water, most of that water is not suitable for human consumption. Today, hundreds of millions of people in vast regions of the world do not have access to water to meet their basic needs. Natural disasters also create conditions which limit the availability of water that is suitable for human consumption. Industrial processes use significant amounts of water which require treatment before discharging to surface water systems. Municipal wastewater treatment systems discharge their effluents which often impact the aquatic organisms. This paper provides a survey of new developments and innovations relative to water treatment for drinking purposes and wastewater treatment during the period from 1999 to 2007. For drinking water treatment, the recent technological advancements relate to primarily filtration (media filtration and membrane systems), disin- fection processes, ion exchange, and carbon adsorption processes. For wastewater treatment, a significant majority of recent developments relate to biological processes and advanced treatment technologies such as adsorption. A review of the recent patents show innovative designs for treatment units, efficient approaches for water quality, as well as nanotechnology applications for removing impurities and disinfection purposes. *Address correspondence to this author at the Florida International University, Civil and Environmental Engineering Department, Engineering Center 3600, Miami, Florida 33174, USA; Tel: 305 348 2928; E-mail: tanselb@fiu.edu 2. WATER TREATMENT SYSTEMS FOR DRINKING WATER The general treatment of drinking water takes place in several steps to remove dissolved and suspended solids. The treatment processes may include processes such as floccu- lation, sedimentation, and media filtration to remove colloi- dal and suspended solids; ion exchange, carbon adsorption, and membrane processes to remove dissolved solids; and a disinfection step often achieved by chlorination, ozonation, and ultraviolet radiation (UV). Drinking water is obtained either from surface water or ground water aquifers. Figure 1 presents the general schematics of conventional treatment processes for drinking water treatment depending on the source water characteristics. The main concerns with surface water aquifers are the suspended solids and organic matter which may be present due to storm water runoff. Therefore, presedimentation, coagulation or coarse filtration processes are generally used for water treatment followed by disinfection. The main concern with the ground water aquifers which are used as drinking water sources are the presence of dissolved contaminants such as salts, organics, or gasses. As a result, in general aeration is used to remove dissolved gasses followed by softening to remove dissolved salts prior to disinfection. Regardless of the water source, when there is a need to further remove dissolved organics; air stripping, ion exchange, carbon adsorption, or membrane filtration processes may be used. A review of the recent patents show innovative design schematics for unit processes, efficient systems for water quality and quantity management, and nanotechnology applications. A significant amount of patents relate to filtration (media filtration and membrane systems), disinfection processes, ion exchange, and carbon adsorption technologies. 2.1. Filtration Systems Filtration systems can be divided into several categories depending on the type of the media used for filtration and the