Whenever a raw water source has a TDS of more than 200 ppm, an RO plant is installed to reduce the TDS. Typical bore-well water TDS are from 500 ppm to 5,000 ppm. Any source of raw water has three contaminations. They are physical, chemical and microbiological. A reverse osmosis water treatment plant is installed to reduce dissolved chemical contaminations. The main dissolved chemicals are calcium and magnesium, hardness, Iron, manganese, chlorides, sulphates, and nitrates, cumulatively called total dissolved solids (TDS).
To remove the physical contamination, a pre-treatment is used, which comprises sand filters, cartridge filters, tube settlers, coagulants and flocculants depending on the total suspended load. Raw water and RO-treated water can have other contaminants, such as colour, odour, dissolved gases, pesticides, fertilizers, TOC, and microorganisms, which RO plants cannot remove. An ozone generator is the best technique to eliminate the above-listed contaminant, which the RO plant cannot remove.
Application and Advantages of Ozone Generator:
Ozone generator for RO plant:
Raw Water Ozonation:
To prevent the RO membrane from bio-fouling and increase the life of the RO plant, chlorine is being used as a
disinfectant. The residual chlorine has a long shelf life and can permanently oxidize the RO membrane. An
activated carbon filter (ACF) is used. The drawback of ACF is that once it adsorbs the residual chlorine, the
water becomes free from disinfectant, and the micropores of carbon granules become a breeding ground for
bacteria. In this case, an ozone generator can be used in place of chlorination. The best available technology
(BAT) for water disinfection is ozone dosing.
Sodium metabi sulphate (SMBS) can also be added to chlorinated water to neutralize the residual chlorine.
Both chemicals increase the TDS and reduce the recovery of water post-RO plant.
Comparison between chlorination and ozonation:
| Ozone | Chemicals | |
| 1 | Ozone is produced/generated at the site | Chemical needs to be stored, ordered, and transported. |
| 2 |
Ozone generation is only a capital cost. No raw material is required to generate ozone. Ambient air is raw material to produce ozone. | Capital costs are low, like those for the online dosing systems, but continuous chemical use is required, so operating costs (OPEX) are high. |
| 3 | Ozone is approved as a food and water by USFDA/Organizes | Chlorine chemical is banned for human and environmental safety. |
| 4 | As per IBWA, ozone should be used as a disinfectant. | Chlorine cannot be used as a disinfector due to harmful DBPs |
| 5 | There is no chemical residue in ozonation | Chlorine residue remains in product water for a long time. |
| 6 | Ozone DBPs are not so harmful to humans and the environment. | Chlorine DBPs are extremely harmful to nature and the environment |
| 7 | Ozone is a powerful disinfection | Chlorine has lower disinfection power |
| 8 | Microorganisms cannot develop resistance/immunity to ozone | Microorganisms can develop resistance to chemical disinfection |
| 9 | Ozone is a powerful oxidant with a potential of 2.07 | Chlorine has a low oxidant potential of 0.94 |
| 10 | Ozone is effective on pesticides | Chlorination has poor effectiveness against pesticides |
| 11 | Ozone can reduce TOC | Chlorine cannot reduce TOC |
| 12 | Ozone works on a wide pH range | Chlorine has a narrow pH range |
CONTACT US
Email : solution@chemtronicsindia.com
Phone : +91-22-4006 9933
Mr. Sunil Shah : +91- 932 123 4527
Connect with us on :
