Disinfection – UV
The main purpose of the water disinfection system is to ensure that drinking water is safe and all of the pathogenic microorganisms are eliminated. the UV action mechanism for killing and disinfecting microorganisms generally involves the absorption of high energy UV photons by DNA, which is eliminated by combining the photons with DNA.fig.1 in water disinfection methods, the UV mechanism is used to remove existing microorganisms in water or wastewater. chlorine produces hazardous compounds during disinfection, UV does not produce any residual compounds (such as THMs).
Ultraviolet (UV) disinfection is one of the modern methods of final water treatment. the use of the UV package in disinfecting the water has many advantages, including the following:
- Quick and safe disposal of bacteria without the use of chemical additives
- Photochemical oxidation of unwanted substances and particles
- Lacking the formation and production of THM, AOX and other unwanted compounds
- No odor or taste in the water
- No need to carry and store chemicals
- Non-dependence on pH
- Need little space
- Low investment and current costs, along with high efficiency and high degree of reliability
The source of the UV light lamps is low or medium pressure. The lamps designed by LIT are LPHO (low intensity high intensity) lamps with a wavelength of 254 nm.
As per following table, the major differences between low and medium pressure UV lamps are described.
|Heat the lamp at wavelength UV-C||-800 pC 900||90 oC|
|Continuous cleaning||Continuously||NO NEED|
|The produced light spectrum||Different wavelengths lead to the formation of algae.||Amalgam lamps
(high intensity low pressure) are 254 nm
Another Advantage of LPHO (Low Pressure High Output) (Amalgam):
- High efficiency of UV in each lamps: Efficiency of LPHO lamps is about 35%
- Amalgam lamps contain no free/ liquid mercury: however, in case of lamps breakage (however the probability is too low), so no toxic mercury can get into the water system. so it is not necessary to consider automatic equipment for failing of system.
- High Lifetime for lamps: Amalgam life time between 12000-16000 hours
- UV systems in open channels
- UV systems in pressurized channels
Depending on how the flow in the open channel or under pressure, the equipment is designed and manufactured in groups MLP, MLV and DUV.
- Potable water
- Swimming pools and Water parks
- Recycling Water
- industrial wastewater;
DUV (refer to technical sheet)
- Operating pressure up to 10 bar (up to 20 bar as per client requested). Figure 2, Fig. 3 and Fig. 4
- Low and medium capacity standard equipment (3,500 m³ / h)
DUV / Pro (Refer to Technical Data Sheet)
- Large-scale cross-flow systems with a capacity of 500 to 10,000 m³ / h
- Operating pressure up to 10 bar (up to 16 bar as per client requested). (Fig. 5, Fig. 6 and Fig. 7)
MLV and MLP groups
there are two types of open canal systems with powerful amalgam lamps (300-900 w):
- MLP group, the number of lamps in the UV modules is between 4 and 18 (Fig. 8) (refer to the Technical Data Sheet)
MLV group, the number of lamps in each vertical U module is between 24 and 36. (Figure 9) (refer to the previous profile sheet)
To ensure the proper design of the system and optimize energy costs, the LIT offers designing and selection of equipment according to the customer’s requested in accordance with the input parameters of the project design
Some of the projects accomplished by LIT are as follows.
UV open channel system for drinking water treatment
South Korea, Capacity: 330,000 m3 / day
Closed systems UV
France, Capacity: 36,000 m3 / day
UV Disinfection Units for Drinking Water:
Russia, Capacity: 63 200 m3 / day