wastewater reuse final (1)
TRANSCRIPT
Potable water from industrial
wastewaterPRESENTED BY:
AVINASH RAICHEMICAL ENGG.
(III- YEAR)
Purpose:To manage water discharged from industries so as to reduce the threat of water pollution.
Pre-treatment. Preliminary treatment. Primary treatment. Secondary treatment. Sludge (biosolids) disposal.
STEPS INVOLVED
Pre-treatmentOccurs in business or industry prior to discharge.
Prevention of toxic chemicals or excess nutrients being discharged in wastewater.
Removes large objects and non- degradable materials.
Protects pumps and equipment from damage.
Bar screen and grit chamber.
Preliminary Treatment
Preliminary Treatment
Bar Screen Catches large
objects that have gotten into sewer system such as bricks, bottles, pieces of wood, etc.
Primary Treatment A physical process. Wastewater flow is slowed
down and suspended solids settle to the bottom by gravity.
The material that settles is called sludge or biosolids.
Primary Treatment
Secondary treatment
Degrade biological content (dissolved organic matter) of the sewageEx: human waste, food waste, soaps,
detergentAdded bacteria and protozoa into
sewage3 different approaches
Fixed film systemSuspended film systemLagoon system
Fixed Film SystemsGrow microorganisms on
substrates such as rocks, sand or plastic.
Wastewater is spread over the substrate.
Ex: Trickling filters, rotating biological contactors.
Suspended Film SystemsStir and suspend microorganisms
in wastewater. Settled out as a sludge.Pumped back into the incoming
wastewater. Ex: Activated sludge, extended
aeration.
Lagoon SystemsHold the waste-water for several months. Natural degradation of sewage.Usually reeds are preferred.
Secondary Effluent
Sludge treatmentPrimary sludge usually have strong
odorsSecondary sludge have high
concentration of microorganismGoals of treatments are:
Reduce odors.Remove water and reduce volume.Decompose organic matter.
Sludge disposalSuperheat sludge and convert
into small granules that are rich in nitrogen.
Sell it to local farmer as fertilizer.
Spread sludge cake on the field.Save landfill space.
Summary Of Process
Other methods for water treatment
Chlorination.UV light radiation.Ozonation.
Chlorination Most common.Advantages: low
cost & effective.Disadvantages:
chlorine residue could be harmful to environment.
UV light radiation Damage the genetic
structure of bacteria, viruses and other pathogens.
Advantages: no chemicals are used
water taste more natural
Disadvantages: high maintenance of the UV-lamp
OzonationOxidized most pathogenic microorganisms.Advantages: safer than chlorination. Fewer disinfection by-product.Disadvantage: high cost.
ConclusionsMany current uses for recycled
wastewater.Varying levels of treatment required.Advantages:
Conserve potable water.Reduce effluent to environment.
Potential for much greater use in future.
THANK YOU!!!!!
Any Questions…