Disposal of Sludge and Treatment

8/2/2019 Disposal of Sludge and Treatment

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A SEMINAR PRESENTATION

ON

DISPOSAL OF SLUDGE AND

TREATMENT


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INTRODUCTION

Sludge- organic matter which settles downin primary and secondary sedimentationtanks.

Types- raw95% moisture content

secondary96-98% moisture cont.

Decomposition of organic matterfoul gas,

pollution, health hazards.


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SOURCE OF SLUDGE

Domestic sewage

Industrial sewage

Water treatment plants


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TYPES OF SLUDGE

Primary sludge

Humus sludge

Activated sludge

Digested sludge


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CHRACTERISTICS OF SLUDGE

PHYSICAL

includes moisture, density, color,

texture, fluidity and plasticity etc.

CHEMICAL

includes organic matter, volatilesolids, Nitrogen, phosphate, fats etc.


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SLUDGE TREATMENT

Main objectives-

Digestion of organic matter by Commonmethods.

Destruction of pathogenic organisms.

Safe and aesthetically acceptabledisposal of sludge.

By product of methane is used as fuel &and helps in controlling temperature andalso generates power.


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UNITS OF TREATMENT

Thickening1. Reduction of moisture content of raw

sludge.

2. Helps in reducing capacity of digestion tankand provides control of digestion condition.

3. It can produce sludge of less than 10% solidcontent.

4. Units of thickening are gravity thickener,floatation thickener, elutriation thickener.


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UNITS OF TREATMENT

Digestion1. Results in reduction of organic content.

2. Improved drain ability.

3. Greatly reduces odor of the pollutantmatter

4. Overall reduction in the volume of the

sludge finally to be deposed.5. Units of digestion are anaerobic &

aerobic


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UNITS OF DIGESTION

Anaerobic digestion

converts sludge into liquid & gases andalso reduces odor, volume, putrescence &produces gases.

Two process are single and double stage.

Bacteria like saprophytic organisms are

present that react on complex organicmatter and decomposed.


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UNITS OF DIGESTION

Diagram of high rate two-stage anaerobic sludge digester


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UNITS OF DIGESTION

Temperature of anaerobic digestion

Mesophilic digestion

Thermophilic digestion


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UNITS OF TREATMENT

Dewateringproduces sludge of greater

than 10% solid content and is used afterdigestion process.

Dewatering by sludge drying beds.

Dewatering by mechanical methods by

vacuum filtration.


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METHODS OF DISPOSALS

Partial disposal

Incineration

sludge burnt in incinerator.

Ultimate disposal

disposal by crops land disposal by oceans


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CONCLUSION

MISCONCEPTIONS- unimportantadditional operation, increase in total costof waste water treatment.

IMPORTANCE- represents SS and BODloads, impact of biological processes,stabilized sludge considers hygienic and

aesthetic requirements, aerobic digestioncontains lower BOD value than anaerobicdigestion.


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Disposal of Sludge and Treatment