Advanced wastewater treatment technologies can allow industrial enterprises to reuse water and thus decrease industries use of fresh water resources. Currently, these processes are expensive and are probably only suitable for developed economies. This is compatible with the nature of industrial water use which increases with per capita GDP.
Industries consuming the most water include textile, chemistry, paper and food industries. Studies done in the EU and the US have shown that advanced water treatment technologies can increase reuse of water, thereby reducing the demand on freshwater resources.
Advanced oxidation process (AOP) using ozone and hydrogen peroxide combined with various membrane separation technologies can make industrial wastewater suitable for reuse. AOP is able to break down organic materials that are not readily biodegradable, sometimes referred to as refractory, making them amenable to biological treatment processes. The ozone reacts with the peroxide to form hydroxyl radicals. The hydroxyl radicals are a non specific oxidizing agent that breaks down organic materials into smaller molecules. Water quality is improved in other ways, for example reduction in odor and color.
The produced water can be used for different applications within the industrial complex such as cooling water make-up, water for back washing filters and other applications where the water quality is not as important. Even if the water is discharged, it is much less toxic and the environment can absorb it much more easily.
A further advantage of AOP, unlike membrane processes, is that there is no stream of concentrated waste formed. The entire water stream is treated to an higher level of quality. This offers the potential of zero liquid emissions.
Water reuse with AOP is a proven alternative, but its application is strongly dependent on economics. These technologies are both capital and energy intensive. the application of AOP will thus depend on water availability, quality and price, as well as regulatory requirements for zero emissions of polluted water.
Given the increasing limits on water resources and increasing regulations, AOP technologies such as ozone peroxide are likely to find ever increasing application.