Textile Industry

Wastewater from textile plants is as diverse as the processes used in the industry. Still, one can make some general statements about the wastewater:

-    it contains few bacteria

-    the proportion of organic nitrogen is small

-    heavy metals occur only when the use of metallic dyes

-    temperatures are high, raw water being between 20°C and 30°C, sometimes even higher

-    wastewater  is generally alkaline

-    the proportion of phosphates depends on the process used

An important criterion for estimating the afflux of wastewater is the extent to which dyes are diluted. The greater dilution, the more material will enter the wastewater.

In wet processing textiles there are four basic operations with their typical chemicals. The following table summarize these.

The wastewater must usually be neutralized before discharge. Sometimes this can be done simply by collecting and allowing it to mix. Wastewater from textile mills rarely has the right proportions of organic material to act as feedstock for bacteria in a biological treatment stage. Treatment often use liquor from communal drains. Treatment is easier if buffer tanks can store the sporadic discharge of large quantities. If further treatment is necessary for specific substances, these may have to be treated specifically by precipitation, flocculation, filtration or adsorption.