ETP (Effluent Treatment Plant)

ETP (Effluent Treatment Plant) is the process design to treat and reuse or/and safely dispose off industrial waste water into the environment.

Influent- Untreated industrial waste water.
Effluent- Treated industrial waste water.
Sludge- Solid part remaining after treatment of industrial waste water.

Treatment Level and Mechanism in ETP

Treatment Level

Preliminary
Primary
Secondary
Tertiary

Treatment Mechanism

Physical
Chemical
Biological

Preliminary Treatment

Screening- Screen with opening of uniform size (max 10mm) is used to separate physical impurities such as plastic, cloth, tissues etc.
Sedimentation- Suspended solids are removed from water using gravity.
Clarification- Solids separated from fluids.

Primary Treatment

Physical and Chemical Treatments are used in here

pH Control
- pH is adjusted to make the wastewater pH neutral.
- For acidic waste: NaOH, CaCo3, Ca(OH)2 etc.
- For alkali waste: H2SO4, HCL.
Coagulation– Chemical coagulants such as Alum (Al2 (SO4)3) are added in-order to collect smaller particles into larger particles called flocs.
Flocculation– Chemical flocculants such as polyelectrolyte are added in-order to make lager flocs to come together and make lumps.

Secondary Treatment

Biological and Chemical Treatments are used in here

Aerobic Process
- Aerobic treatment takes place in presence of Oxygen.
- Utilizes microorganism to convert free oxygen into carbon di oxide, water and biomass.
Anaerobic Process
- Take place in absence of oxygen.
- Use microorganism that do not require oxygen to assimilate organic impurities.
- Final product is methane and biomass.

Tertiary Treatment

Final cleaning process to remove remaining inorganic compounds in the wastewater before it can be either released into environment or used to further treatment

Alum- Used to remove additional phosphorous particles in the waste water and help group the remining solid particles for their easy removal.
Chlorine- Disinfection of Tertiary treated waste water.