Question

Explain three phases by which treatment of industrial effluents can be done.

Answer 1

Control of environmental degradation caused by industries

Answer 2

Treatment of industrial effluents

Explanation:

The three phases by which industrial effluents are treatment are as follows:

1. Primary treatment is done using mechanical machines to remove colloidal solids, emulsified oil and a small portion of BOD and COD.  This involves screening, grinding, flocculation and sedimentation.
2. Secondary treatment is a treatment process for wastewater to achieve a certain degree of effluent quality by using a sewage treatment plant with physical phase separation to remove settleable solids and a biological process to remove dissolved and suspended organic compounds.
3. Tertiary treatment is the final cleaning process that improves wastewater quality before it is reused, recycled or discharged to the environment. The treatment removes remaining inorganic compounds and substances, such as the nitrogen and phosphorus.