sewage treatment plant by UASB technology

DESIGN OF UASB BASED TECHNOLOGY FOR MUNICIPAL SEWAGE(45MLD) OF TIRUPATI

RUPENDRA BABU K M12785A0115

[email protected]

INTRODUCTION

• By the end of 2030, it is accepted that Tirupati population is around 5,75,000.

• The per capita generation of sewage is around 80L/C/d. Hence, a total of 45 MLD of sewage is going to be handled by Tirupati municipality without causing any impact on human health and environmental damage.

• The current capital cost –effective technology is UASB system although operation and maintenance costs are minimum similar to conventional sludge process.

LITERATURE REVIEW ON UPFLOW ANAEROBIC SLUDG BLANKET (UASB)

• The UASB was developed for the treatment of medium and high strength waste water in 1972.

• In India UASB can be extensively applied for sewage treatment.• The UASB reactor has a feed inlet distribution system at the bottom and a three-

phase separator at the top. • The raw influent is distributed over the bottom and mixed with the anaerobic

sludge bed through the inlet system. • The blanket of anaerobic sludge is maintained in the lower section of the reactor

and the incoming wastewater is forced to percolate upwards through this blanket. • Contact between sludge and feed is increased by the Biogas production. • The sludge and the Biogas are separated from the effluent in the GLSS separator. • The absence of mechanical mixing and sludge recirculation improve the settle

ability of the sludge.

CONTD…

Advantages of UASB.

• Limited production of stabilized, easily de-waterable excess sludge,• Low energy consumption,• Absence of noise and odour nuisance,• Proven technology ,• Low initial investment and maintenance cost,• Stable process• Low nutrients requirement,• Methane rich biogas production.

OBJECTIVES

The major objective of the present project is:

• To suggest a sustainable municipal sewage treatment plant for tackling 45MLD of sewage generation in tirupati by the year 2030.

• To provide hydraulic design for various components of sewage plant in general and UASB components in particular.

• To arrive a capital and operation and maintenance cost on unit basis

DESIGN PARAMETERS

1. Hydraulic Retention Time (HRT) = 8 – 10 hours2. Solids Retention Time (SRT) = 30 – 50 days3. Organic loading on Sludge blanket = 5 – 10 kg.COD/m3- d4. BOD/COD removal efficiency = 85%/60 %5. Inlet points : Minimum 1 point per 3.7 – 4 m2 Floor Area6. Flow regime : Constant rate by pumping7. Up-flow Velocity = 0.5 m/hr. ( Average Flow ) = 1.0 m/hr. ( Peak Flow )8. Sludge production = 0.15 – 0.25 kg. of solids/ kg. BOD9. Sludge drying time = 12 days ( Monsoon ) = 8 days ( Winter ) = 6 days ( Summer )

10. Gas production = 0.2 to 0.3 m3/kg.COD removed11. Gas quality : CH4 = 65 to 68%

CO2 = 30 to 35%

H2S = 0.5 to 1.0%

12. Gas utilization: Boiler fuel : 1 m3 of gas is equivalent to 1.2 kwh

electricity13. Post Treatment : Required

LAYOUT OF UASB TRETMENT PLANT

HYDRAULIC DESIGN OF TREATMENT UNITS

sewer pipe screen chamber

Grit chamber wet well and dry well

SPLITTER BOX

UASB REACTOR

SPLITTER BOX

UASB REACTOR

UASB REACTOR

UASB REACTOR

UASB polishing unit for UASB effluent

• UASB

MANPOWERPARAMETER ASP TF WSP MBBR SBR MBR UASBTotal Annual Manpower O& M cost, Rs. Lacs per MLD

0.32 0.28 0.23 0.32 0.33 0..34 0.3

ENERGY GENERATION

PARAMETER ASP TF WSP MBBR SBR MBR UASB

BIOGAS GENERATION PER CUM

55-70 55-70 NILL NILL NILL NILL 35-50

BIO ENERGY GENERATION KWH

25-35 25-35 NILL NILL NILL NILL 20-30

conclusion

• Compare to other treatment plants UASB has capital, operation and maintenance cost minimum.

• BOD and COD removal efficiency- 85%and60%• Energy generation in the form of methane gas 1.16kwh energy is produced for every 1 kg of cod removal by anaerobic

process.• Less biomass (sludge) generation.

THANK YOU