Lecture 1: IntroductionLecture 1: Introduction

WastewaterWastewater: liquid effluents derived from domestic : liquid effluents derived from domestic sewage or industrial sources, which for reasons of sewage or industrial sources, which for reasons of public health and for recreational, economic, and public health and for recreational, economic, and aesthetic considerations, cannot be disposed of by aesthetic considerations, cannot be disposed of by discarding them untreated into lakes or streamsdiscarding them untreated into lakes or streams

Types:Types: Industrial: e.g., petrochemical, metallurgical, plastics Industrial: e.g., petrochemical, metallurgical, plastics

industries industries Domestic: sewage, “gray water” (washing, bathing, cooking), Domestic: sewage, “gray water” (washing, bathing, cooking),

food processingfood processing Goals of WWTP:Goals of WWTP:

Reduce organic contentReduce organic content Remove particlesRemove particles Remove/inactivate pathogensRemove/inactivate pathogens Reduce inorganic nutrient levelsReduce inorganic nutrient levels

contaminants of concern in wastewater treatment

suspended solids

biodegradable organics

pathogens, parasites

nutrients

priority pollutants

refractory organics

heavy metals

dissolved inorganics

Municipal Water Municipal Water TreatmentTreatment

Municipal Sewage Municipal Sewage TreatmentTreatment

Primary TreatmentPrimary Treatment

Primary TreatmentPrimary Treatment

Secondary TreatmentSecondary Treatment

Activated SludgeActivated Sludge

Figure 27.20a,b

Activated Sludge Activated Sludge ComponentsComponents

Activated Sludge Activated Sludge ComponentsComponents

Primary treatment of wastewater

trickling filter aeration tank, activated sludge unit

Hyperion WWTPHyperion WWTP

Key DataKey Data     Plant capacity: 300,000 gallons/minutePlant capacity: 300,000 gallons/minute Site size: 144 acres (60ha)Site size: 144 acres (60ha) Associated sewer run: 6,000 miles Associated sewer run: 6,000 miles

(9,600km)(9,600km) Water reclamation for re-use: 6%Water reclamation for re-use: 6% Energy recovery system generation Energy recovery system generation

capacity: 25,000kW (electrical) capacity: 25,000kW (electrical)  Total project cost: $1.4 billion Total project cost: $1.4 billion 

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