IMPURITIES |
EFFECT |
METHOD OF REMOVAL |
Suspended silica turbidity
|
Can clog pipelines and equipments, can choke ion exchange resins and RO membranes
|
- Coagulation
- Setting
- Filtration
|
| Color |
Indication of organic matter, iron etc. and can be harmful to the unit operation ahead. |
- Coagulation
- Settling filtration, followed by activated carbon filter.
|
| Organic matter |
Can foul ion exchange resins membranes and may be detrimental to process. |
- Coagulation
- Settling filtration, followed by activated carbon filter.
|
| Bacteria |
Will depend upon the type of bacteria, can induce corrosion and also harmful to RO membrane. |
- Coagulation
- Filtration
- Setting and super chlorination
- UV
- Ozonation
|
| Iron |
Red water, corrosion, deposit, interferes with dying, bleaching etc. |
- Aeration
- Coagulation
- Filtration
- Filtration through Manganese Zeolite
|
| pH |
High pH or low pH can both induce corrosion. |
- Ion exchange
- Addition of acid or alkali.
|
Calcium, Magnesium
( Hardness) |
Scaling, cruds with soap interfere with dyeing and also harmful to other process. |
|
| Sodium |
Harmless when low in concentration, increases TDS, high concentration can induce corrosion. |
- Ion exchange through cation H+ resin.
- Reverse Osmosis
|
| Bicarbonates, Carbonates, Alkalinity, Hydroxide (Alkalinity) |
Corrosion, foaming and carry over |
- Acid addition.
- Ion exchange by weak acid cation
- Split stream by hydrogen cation resin
- Degasification
|
