wastewater reuse final (1)

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…