An important application for ozone is pulp bleaching. Chlorine is a major pulp bleaching agent, but its application is declining as other bleaching agents take its place such as chlorine dioxide and ozone.
Even in developing countries, efforts are being made to move toward alternatives such as ozone. The Indian company lTC recently launched an environment friendly paper which has been crafted by ITC using a pioneering technology, which is first of its kind in India called “Ozone Treated Elemental Chlorine Free technology”.
Conventionally, elemental Chlorine was used in the bleaching process during paper manufacture. The byproducts of this process include large number of organo-chlorine chemicals, which are toxic and adversely impact the environment. Chlorine dioxide was the second generation technology for preventing the emissions of toxic compounds. Ozone bleaching virtually eliminates the production of byproducts with better results than chlorine dioxide bleaching.
The growing success of ozone in the pulp and paper industry is just another indication of the versatility of ozone and ozone generators.
The market research firm Global Water Intelligence has announced the publication of Water Market USA, a study of the US water treatment market. The study indicates that long-term growth in spending for water and wastewater infrastructure in the United States is “guaranteed,” although spending during 2009 will be reduced.
The largest area of long-term US water infrastructure spending in dollars will be in the expansion of sewer lines while the fastest-growing market will be seawater desalination.
Other fast growing water technology markets from 2009 through 2016 will be ultrafiltration and microfiltration membranes, followed by ultraviolet disinfection, ozone disinfection, membrane bioreactors (RO), and reverse osmosis membrane systems.
Spartan Environmental Technologies supplies technologies for both ozone disinfection and UV disinfection.
Air Products recently announced that HiPOx technology, an ozone-based advanced oxidation process (AOP) water treatment technology, has been granted conditional acceptance by the California Department of Public Health for unrestricted water reuse under Title 22 of the California Code of Regulations. HiPOx injects and mixes ozone with hydrogen peroxide to maximize the production of hydroxyl free radicals. Hydroxyl free radicals are the most powerful oxidant available for water treatment to destroy pathogens and difficult to treat organic contaminants including 1,4-dioxane, chlorinated solvents, petroleum hydrocarbons, and endocrine disrupting chemicals (EDC).
Ozone and ozone-based AOP, like HiPOx, have been shown to provide superior results over conventional ultra violet and chlorine-based disinfection technologies. Spartan Environmental Technologies offers a variety of conventional and proprietary advanced oxidation processes. The approval of this first AOP for water use processes in California show that these technologies will have a much wider range of use than they have today. Currently such AOP are primarily used for ground water remediation and industrial water and wastewater treatment.
Air Products and ITT WEDECO have recently disclosed a process for recovery unused oxygen from ozone generator gas. This is important since oxygen is a major cost factor for producing ozone and the conversion efficiency from oxygen to ozone is only 6-15%. Therefore, in most oxygen fed ozone systems, the vast majority of oxygen is wasted. The process shown in the schematic claims to recover about 70% of the oxygen. The basic process involves adsorbing ozone on a bed of molecular sieves and then stripping the ozone into a dry air stream. The air ozone stream is used for water treatment and the oxygen is recylced or recovered for reuse at the generator. A more detailed discussion is provided at our web page on ozone oxygen recovery.