Water Treatment Process
Impurities in Water
- Suspended Impurities
- Organic Impurities
- Dissolved Organic Impurities
- Dissolved Inorganic Impurities
- Dissolved Gased
Objectives of Water Treatment Process
- To remove color and odor from water.
- To remove the hardness of water.
- To remove the harmful microbes that cause diseases from water.
- To remove murkiness and turbidity of the water.
- To remove dissolved gases present in water.
- To make the water suitable for various purposes like drinking, industrial and many others as per the demand.
Related Problems Caused by Impurities
| IMPURITIES | RELATED PROBLEMS |
|---|---|
| Dissolved Oxygen (ppm) | Pitting Corrosion |
| pH | Corrosivity |
| TSS (NTU / ppm) | Fouling |
| Total Hardness (ppm CaCO3) | Scaling |
| Sodium / Potassium (ppm) | Corrosivity |
| Chloride (ppm) | Corrosivity |
| Sulphate (ppm) | Corrosivity / Scaling |
| Total Alkalinity (ppm CaCO3) | Scaling, Foaming |
| Phenophthalene Alkalinity (ppm CaCO3) | Scaling, Foaming, Corrosivity |
| Silica (ppm) | Scaling |
| TDS / Organics (ppm, Conductivity) | Foaming, Corrosivity |
Types of Water Treatment Processes
Physical Water Treatment Process
- Sedimentation
- Filtration
- Dissolved Air Flotation
Chemical Water Treatment Process
- Pre-chlorination
- Aeration
- Disinfection
Physio-Chemical Water Treatment Process
- Coagulation
- Flocculation
Biological Water Treatment Process
- Slow Sand Filtration
Filtration
Dual Media Filters : These filters work on the principal of depth filtration. The principal media in these filters is quartz grade sand and anthracite. Other supporting media include pebbles of various sizes, crushed gravel and silex.
Activated Carbon Filters : The principal media in these filters is activated carbon. Other supporting media include pebbles of various sizes, crushed gravel and silex.
Water Softening Systems : Hardness in water is caused by certain salts. The main hardness causing ions are Calcium (Ca2+), Magnesium (Mg2+) and Bicarbonate (HCO3-).
Demineralization Process (DM Plant)
Demineralization Water Treatment is a physical process. Ion exchange resins are specially manufactured which help to replace the mineral salts in water.
Cations
Positively-charged ions are known as Cations. These are usually metals.
- Iron
- Calcium
- Magnesium
- Copper
- Sodium
- Potassium
Anions
Negatively-charged ions are known as Anions. These are usually non-metals.
- Chloride
- Carbonate
- Sulphate
- Bicarbonate
- Nitrate
RO Plant
Reverse Osmosis, commonly referred as RO, is a process where water is demineralised by flowing under pressure through a semi-permeable membrane.
A high pressure pump is used to increase the pressure on the salt side of the RO and force the water to flow across the semi-permeable membrane.
Sewage Treatment Plant
Sewage treatment refers to the process of removing contaminants, micro-organisms and other types of pollutants from wastewater in fluent.
Majorly, four methods of sewage water treatment are followed - physical, biological, chemical, and sludge water treatment.
There are three main stages of the wastewater treatment process, aptly known as primary, secondary and tertiary water treatment.
Technologies Used
- ASP: Activated Sludge Process.
- MBBR: Moving Bed Bio reactor.
- SAFF: Submerged aerated Fixed Film.
- SBR: Sequential Bioreactor.
- MBR: Membrane Bio Reactor.
Ultrafiltration System
Ultrafiltration (UF) is a water purification process in which water is forced through a semipermeable membrane.
| TECHNIQUE | MWCO* (Da) |
|---|---|
| Microfiltration | >105 |
| Ultrafiltration | 103-105 |
| Nano filtration | 102M-104 |
| Reverse osmosis | 102 |
Membrane Geometries
- Spiral wound module
- Plate and frame module
- Tubular membrane
- Hollow fiber membrane
Ultrafiltration Module Configurations
- Pressurized System or Pressure-Vessel Configuration
- Immersed System
Application Area
Filters / Softeners
- Residential Complexes
- Hospitals
- Colleges
- Restaurants
- Car Washes
- Food Industries
- Laundry
- Textile Industries
- Mall
- Cooling Tower make up
- Low Pressure Boiler
- Process Industries
RO Plant
- Potable Water
- Offices
- Housing Colonies
- Packaged Drinking Water
- Food & Beverages
- Hospitals
- Pharmaceuticals
- Power Generation Industries
- Petrochemical Industries
- Fertilizers
DM Plant
- Boiler Feed
- Distillery
- Paint Industry
- Chemical Industries
- Power Plant
- Automobile Industries
- Rubber Industries