Secondary Treatment Process

Secondary Waste Water Treatment process involves further treatment of the effluent, coming from the primary sedimentation tank. this is generally accomplished through biological decomposition of organic matter. which can be carried out either under aerobic or anaerobic condition, in this biological spits, bacteria will decompose the fine organic matter, to produce clear effluent.
The treatment reactors, in which the organic matter in decomposed  ( oxidized) by aerobic bacteria are known as aerobic biological units and may consist of

• Filters ( intermittent sand filters as well as trickling filters

• Aeration Tanks with the feed of activated sludge ( ie the sludge, which is settled in secondary sedimentation tank, receiving effluents from aeration tank)

• Oxidation ponds etc. Since all these aerobic units generally make use of primary settled sewage,  they are easily classified as secondary units.