| Ozone | Has been used for several decades in some of European countries for the purpose of disinfection, elimination of color, for the taste and odor control | - Strong disinfectant and oxidation agent
- Very effective against Giardia, Cryposporidium and any other pathogenic microflora
- Facilitates removal of turbidity from water
- Removes foreign tastes and odors
- Does not form chlorine containing trihalomethanes
| - Forms by-products, including: aldehydes, ketones, organic acids, bromine-containing trihalomethanes, (bromoform inclusive), bromates (in presence of bromides): peroxides, brom-acetic acid
- Necessitates the use of biologically active filters to remove by-products
- Does not ensure residual disinfection effect
- Requires significant initial expenses for the equipment
- Considerable expenses for operators` training and installation support
- When reacting with organic compounds, ozone disintegrates them into smaller components, which could become a feeding media for microorganisms growth in water distribution systems
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| Ultraviolet | Exposure of water to UV rays capable of killing various types of microorganisms | - Does not require storage and transportation of chemicals
- Does not form by-products
| - No residual effect
- Not efficient against cysts (Giardia, Cryptosporidium)
- Requires considerable expenses for the equipment and technical maintenance
- Requires considerable operational (power) expenses
- Disinfection activity depends on the water turbidity, its hardness (sediments on the bulb surface), precipitation of organic impurities on the bulb surface, and deviations in the power supply, which effect the wavelength variation
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