sewerage treatment plant (stp) 2016

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Sewerage Treatment Plant (STP)

Upflow Anaerobic Flush Blanket Model(UAFB )

Dr Shyam AshtekarSMBT Medical College Nashik

Jan 2016

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The STP Model

A BC

A: screening and grit removal, B: primary & secondary sedimentation, C: sludge separation and water treatment

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The STP plant• The STP aims to reduce

BOD from 300+ to <30 before water is discharged into river or farms

• The sludge is oxidized and dried to make manure.

• Methane generated in digestion runs the power plant for this STP.

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Screening for solid waste• Sewage is 95%

water, with human and other waste including plastic bags, sanitary pads, grit etc

• The first job is to separate the solid waste by screening

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Solid waste separated

• This is what should not be thrown into toilets and sewers..but we do!

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Grit Chamber

• Removal of sand grit etc.

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Primary Sedimentation (8hrs)• To settle sludge

(organic solid waste)

• The blue pipes collect methane gas going to power generation

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Aeration to help bacterial oxidation of sludge

• The aerobic bacteria need air/O2 to oxidize the sludge

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Secondary Sedimentation (6hrs)• This finally

separates sludge and water and bacterial digestion is still happening

• Sludge is taken off to sludge drying beds from below.

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Sludge drying beds

• Sludge makes a good manure for agriculture

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Liquid chlorine for disinfecting water before discharge

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