Advanced Oxidation Processes
AOPs are particularly appropriate for effluents containing refractory, toxic, or non- biodegradable materials. AOP offer advantages over biological or physical processes, including:
- process operability
- unattended operation
- the absence of secondary wastes
- the ability to handle fluctuating flow rates and compositions.
However, it is important to note that AOPs often come with higher installation and operating costs than conventional biological treatments.
Advanced Oxidation Processes (AOPs) include:
UV Process This process uses ultraviolet (UV) light to promote the formation of hydroxyl radicals. These radicals effectively break down and remove many pollutants from water
Ozone Process Ozone acts as a strong oxidizing agent. It reacts directly with organic compounds and breaks them into simpler, less harmful products.
UV-Ozone Process This method combines UV light and ozone. UV produces hydroxyl radicals, while ozone adds extra oxidizing power. Together, they enhance pollutant removal.
Fenton and Fenton-like Processes The Fenton process uses hydrogen peroxide (H₂O₂) and a ferrous iron catalyst (Fe²⁺) to generate hydroxyl radicals. In contrast, Fenton-like processes substitute other metal ions for iron.
Combination of AOPs This approach mixes oxidants such as ozone, hydrogen peroxide, or persulfate with UV or visible light. The result is the generation of highly reactive radicals that help remove contaminants more efficiently. These are combined with ultraviolet (UV) or visible light to produce reactive radicals.
Laboratory-scale wet air oxidation reactors, often lit with green lighting, are used in industrial wastewater research. These setups help test and improve treatment efficiency.
Each AOP has its own strengths and limitations. Therefore, selecting the most suitable process depends on the type of pollutants in the water and the treatment goals. Additionally, AOPs can be paired with other technologies to increase effectiveness.