UV oxidation is a destruction process that oxidizes organic matter in water by the addition of strong oxidizers ozone (O3) and/or hydrogen peroxide (H2O2) and irradiation with UV light.
Destruction of target contaminants is caused by:
- direct reaction with the oxidizers
- direct UV photolysis (the process by which chemical bonds of the contaminants are broken under the influence of UV light)
- the synergistic action of UV light with the oxidizer (UV/O3 or UV/H2O2)
Reaction products of photo-degradation vary according to the matrix in which the process occurs.
Advanced UV oxidation processes can be configured in batch or continuous flow modes, depending on the throughput under consideration.
These days the combination of UV light with hydrogen peroxide (H2O2) is very popular to breakdown organic micropollutants in water.
UV light emitted by both medium-pressure (MP) and low-pressure (LP) lamps converts the hydrogen peroxide molecule into hydroxyl radicals. Hydroxyl radicals are non-selective, reacting with all kinds of organic compounds creating smaller, biodegradable compounds. In the most optimal situation, these compounds convert to CO2 and H2O.
The absorption curve of H2O2 is most optimal at a low wavelength (200nm) and decreases with higher wavelengths (up to 280nm). Both lamp technologies, low-and medium pressure, emit wavelengths in the spectrum between 200 and 280nm and can be used.
The choice of lamp technology to be used, LP or MP, depends on several factors, such as:
- water characteristics (organics, precursors)
- operational costs (energy, lamp life)
- investment costs (equipment, footprint, building)
The duration of operation and power input depends on influent water quality (UV transmittance, concentrations of contaminants) and UV quantity (flow rates) to treat it.
A practical issue is the potential fouling of the quartz sleeves and UV sensor due to the water quality. An automatic cleaning device may be required in certain situations.
bestUV designs UV systems with both lamp technologies (LP and MP) and provides the know-how to build the right UV system for a specific application and site.
Contact the ‘experts in ultraviolet light’ to fully optimise your new or existing water treatment system with bestUV technology.