Sewage Treatment

Effluent Treatment

Water Treatment


Typical Design Raw Effluent Parameters for High BOD Wastewater
 pH  3-8
 BOD  4000-5000 mg/l
 COD  8000-10000 mg/l
 TSS  500-800 mg/l
 Oil & Grease  100-200 mg/l


Typical Outlet Parameters after Secondary Treatment

 pH  6 - 8
 BOD  < 30 mg/l
 COD   < 250 mg/l
 Total Suspended Solids (TSS)  < 100 mg/l
 Oil & Grease  < 10 mg/l


Treatment Philosophy


The raw effluent discharged from the process will first pass through a Fat Trap where free floating fat will be removed and skimmed off manually from the top of the tank. From this Tank it will be collected in an Equalization Tank. From this unit effluent will be pumped to packaged skid mounted DAF (Dissolved Air Floatation) Unit. Effluent will be collected inside the first compartment of DAF Unit from where it will overflow to 2nd compartment where individual plates/ tube pack will be provided for settlement of solids.

In DAF Unit Clear water will be collected in Clear Water Tank from where a part of the water will be recycled back to a Pressurized Tank. Air from atmosphere will also be taken inside the Pressurized Tank, where by air water mixture at a particular pressure will be liberated into the first compartment.

Overflow from the DAF Unitwill be collected in an Aeration Tank/ SAFF Reactor/ FAB Reactor, where removal of organic matter will take place. The type of reactor will be decided based on area available at site, underground/ aboveground process, height restriction etc. In this Reactorfixed surface/ floating surface/ diffused aeration system will be provided for effective mixing & aeration necessary for proper growth of micro-organisms. For proper growth & maintenance of micro-organisms special bacteria (EM) culture will be dosed periodically.

The effluent comprising of the biological floc from the Reactorwill overflow into Tube/ Plate/ Lamella Settler or Secondary Clarifier where they will settle down at the bottom. This underflow sludge will be recycled back by the Sludge Pump to the Reactorto maintain the population of micro-organisms. Excess sludge will be periodically transferred to Sludge Drying Beds or passed through a Filter Press, where sludge will be collected & disposed off whenever required.


Treatment of Sludge


Filter Press Feed Pump will pump scum & sludge generated from DAF Unit & excess sludge from Settling Tankthrough a Filter Press for concentration of sludge & for formation of sludge cake. The sludge cake will be disposed off and can be used as manure.


  DAF, Aeration Tank & Tube Settler  
  Overflow of Primary Tube Settler  
  Click to enlarge