Advanced oxidation is a complicated wastewater treatment method. The overall notion of how the process works might be difficult to understand at first, and the variety of alternative oxidation processes can be overwhelming.
What is Advanced Oxidation Process?
Advanced oxidation is a kind of oxidation that revolves on the formation of the extremely potent hydroxyl radical (•OH). These extremely reactive oxidization molecules are formed by the degradation of certain chemicals that also function as secondary oxidizers.
Three oxidants in particular are extremely efficient: ozone, hydrogen peroxide, and UV light. They are employed in different combinations — ozone may even be used alone — to generate the (•OH) molecule.
When exposed to large quantities of hydroxide ions or hydrogen peroxide, ozone degrades in a complicated process. By employing massless photons to disrupt atomic bonds, UV light may be employed as a catalyst to break down ozone and hydrogen peroxide.The light can also help to provide a disinfectant and oxidation element to the advanced oxidation process.
When radicals are formed, they degrade pollutant chemicals into intermediates, which are then degraded further by the residual radicals and original oxidants. Finally, the pollutants are primarily degraded into simple inorganic substances such as water, carbon dioxide, and salts.
Because these systems are sensitive to suspended particles and other chemicals, they are usually employed in tertiary treatments (known as hydroxyl scavengers). By blocking UV light and interacting with the (•OH) radical over the target molecules, these scavengers diminish oxidation efficiency.
Misconceptions regarding Advanced Oxidation Process
1: A UV disinfection system may easily be converted into a UV/H2O2 advanced oxidation system by simply adding H2O2
Though incorporating a UV disinfection system into an advanced oxidation system is not impossible, it is more difficult than just adding an H2O2 tank. The two processes operate in quite distinct ways, and the system designs are therefore fairly diverse.
Because H2O2 has a poor UV adsorption coefficient, substantial amounts of peroxide must be added, and the UV dosage may also need to be increased. Furthermore, peroxide dosage must be done carefully to avoid leftover peroxide. If there is any, it must be eliminated before to use or discharge, which may need a whole new therapy.
2: The use of ozone alone is usually a sophisticated oxidation process
As stated, advanced oxidation systems are characterised by their ability to generate significant amounts of hydroxyl radicals (OH radicals) for successful treatment.
An ozone system that has not been specially engineered to increase OH breakdown cannot be deemed in advanced oxidation.Ozone is an oxidant in and of itself. It is not as strong as the OH radical, though, and its response times are much slower. The insertion of ozone into an alkaline pH feed solution is usual for converting an ozone system into an advanced oxidation system.
3: It cannot be employed on a lesser scale
Some sophisticated treatment methods may necessitate enormous spaces to house the required equipment, whereas advanced oxidation system does not. It may also be simply scaled down for smaller community drinking water applications. Some systems can have flow rates as low as 25 gallons per minute or lower.
4: Generates garbage in the same way that any other treatment procedure does
The disposal of extracted solids and other concentrated pollutants is one of the most expensive aspects of wastewater treatment operations. Advanced oxidation (AOP), on the other hand, does not generate concentrated by-products. AOP successfully dissolves more complicated substances into simple, harmless, biodegradable molecules as it is.
Hopefully, this clarifies some points for you regarding this procedure. Because advanced oxidation process is a complex process, it is easy to misinterpret elements of its functioning and applications.
When correctly built, it is a very beneficial and successful wastewater treatment technology. The operational expenses might be rather significant depending on the extent of pollution. However, it is a technology that should be considered for the right applications.