UV

(Ultra Violet) It is a spectrum of high-energy electromagnetic waves that is also present in the sun. They are used for disinfection in various industries. Ultraviolet radiation can be used to disinfect water, foodstuffs, medical equipment and industrial supplies, etc.
Ultraviolet (UV) radiation: Ultraviolet radiation is a wave in the range of electromagnetic waves with a wavelength shorter than visible light but longer than the X-ray.
This radiation can be subdivided into the following groups in terms of penetration:
– NUV Near ultraviolet with wavelength 400-200 nm (apparently low risk to environmental health)
– VUV-VACUUM UV (High Risk but Dangerous)
– XUV or EUV or XUV1-31nm Extreme UV (very harmful to environmental health)

*Nm equals one billionth of a meter

How to detect radiation:
Ultraviolet radiation was discovered by chance by observing the discoloration and darkening of silver solids in direct sunlight. In 1801 German scientist Johann Wilhelm Reiter observed from his observations that ultraviolet radiation, which is invisible, was a major factor in the darkening of silver chloride-coated paper plates. He called the phenomenon “chemical radiation” at the time.
Radiation In the light of the impact of this invisible radiation on human health and the environment, radiation should be subdivided into the following categories:
UVA 400-300nm apparently low risk
UVB 320-280nm dangerous

Uses of UV radiation for disinfection:
Breeding and rearing of cold water fish
Breeding of shrimp
Breeding of sturgeon
Breeding of ornamental fish

Physicochemical effects of UV light on water polymers:
UV light from solar radiation or other UV light sources is the initiator of the Oxidation of polymers.
The type and combination of polymers determine the amount of UV absorption and therefore the degree of degradability of these polymers.
UV absorption by polymers produces free radicals such as peroxides and molecules with unpaired electrons. These radicals decompose the polymeric material through multiple oxidation reactions, resulting in physical and chemical changes such as discoloration, transparency, fragility, etc. in the polymers. It is possible to prevent or reduce the degradation of polymers through mechanisms such as quenching of certain polymer molecules, the use of antioxidants, and the mechanism of reducing UV radiation absorption.

Factors affecting UV disinfection efficiency:

Unlike many disinfectants, UV rays are a physical process that depends on the contact time to inactivate the pathogen. To achieve inactivation, UV radiation must be absorbed by the microorganism, so any factor that prevents the UV from reaching the microorganism reduces the effect of disinfection.
Reports have shown that pH is not effective on UV disinfection; factors that influence the efficiency of UV disinfection include:

The deposition of solids on the surface of the UV lamp can reduce the UV intensity of the UV lamp, thereby reducing the disinfection efficiency. Waters with high concentrations of iron, hardness, hydrogen sulfide, and organic matter are highly susceptible to sediment formation, which gradually reduces the efficiency of UV irradiation.Variety of chemicals can reduce UV radiation, which include humic acids, phenolic compounds and lefonateligenin, chromium, cobalt, copper and nickel.

The community of microorganisms and turbidity is the level of suspended particles, the breeding and storage site of bacteria and other pathogenic bacteria. Therefore, the presence of particles on the disinfection efficiency is effective because it protects the bacteria from UV radiation as well as disperses UV light, however, high turbidity has an effect on the disinfection. Like the particles that cause turbidity, the community of microorganisms can also be effective in disinfecting efficiencies, as they cause pathogenic bacteria to be replaced, virtually sheltered.

Advantages of UV radiation in fish pools:

Effective elimination of microbial contamination without chemical contamination
Immediate disinfection of water at the fish farm
Effective disinfection of chlorine and ozone resistant microorganisms
No harmful side effects and chemical pathogens in the pools
Lack of taste and chemical odor in water
Unchanged physical and chemical quality of water
No immediate side effects and allergies

Environmental Impact of Using UV:
Because ultraviolet radiation is not a chemical agent. it does not produce any toxic residues, but specific chemicals may be altered by ultraviolet radiation. It is generally thought that these compounds are decomposed harmlessly, but further research is still needed. It is now to be believed that ultraviolet disinfection has no favorable or adverse environmental impact.

Benefits of disinfection:
Inactivate microorganisms in seconds, including bacteria, viruses and parasites
Replacing or reducing the use of chemicals
No need for reaction tanks or secondary pumps
Low maintenance costs
Low operating costs
Low and appropriate investment costs