biological treatment of wastewater
TRANSCRIPT
7/23/2019 Biological Treatment of Wastewater
http://slidepdf.com/reader/full/biological-treatment-of-wastewater 1/16
BIOLOGICAL TREATMENT
G. N. MAHESHIKA
09
TH
JUNE, 2O15
WASTEWATER ENGINEERING
7/23/2019 Biological Treatment of Wastewater
http://slidepdf.com/reader/full/biological-treatment-of-wastewater 2/16
OBJECTIVES
• Coagulation and removal of organic and inorganic
non-settleable colloidal particles
• Stabilization of dissolved organic matter
7/23/2019 Biological Treatment of Wastewater
http://slidepdf.com/reader/full/biological-treatment-of-wastewater 3/16
CLASSIFICATIONS
1. Processes according to operational conditions• Aerobic process
• Anaerobic process
•Facultative process
• Anoxic process
2. Processes according to microbial maintenance in
the system• Suspended growth process
• Attached growth process
7/23/2019 Biological Treatment of Wastewater
http://slidepdf.com/reader/full/biological-treatment-of-wastewater 4/16
Biological Wastewater Treatment
Suspended Growth
Aerobic
Activatedsludge process
Extendedaeration system
Aeratedlagoons
Wastestabilizationponds
Anaerobic
Complete mixanaerobicreactor
Contactanaerobicreactor
Attached Growth
Aerobic
Tricklingfilters
Bio-towers
Rotating
biologicalcontactors
Submergedfilters
Anaerobic
Packed bed up-flow and down-
flow reactors
Extended reactor
Fluidized bedreactor
Up-flow
anaerobic sludge
blanket reactor
7/23/2019 Biological Treatment of Wastewater
http://slidepdf.com/reader/full/biological-treatment-of-wastewater 5/16
ASSIGNMENT
7/23/2019 Biological Treatment of Wastewater
http://slidepdf.com/reader/full/biological-treatment-of-wastewater 6/16
PRINCIPLE OF AEROBIC BIOLOGICAL TREATMENT
•
7/23/2019 Biological Treatment of Wastewater
http://slidepdf.com/reader/full/biological-treatment-of-wastewater 7/16
•
PRINCIPLE OF ANAEROBIC BIOLOGICAL TREATMENT
7/23/2019 Biological Treatment of Wastewater
http://slidepdf.com/reader/full/biological-treatment-of-wastewater 8/16
AEROBIC VS. ANAEROBIC PROCESSES
•Molecular O2 as TEA
• Wide spectrum of OM
can be oxidized
• More stable end products
• High growth rates of
microorganisms
• More biological sludge
• For large quantities of
diluted wastewater
•SO4
2-
, CO2, organiccompounds as TEA
• End products are odorous
• Slow process
• Low sludge production
• For concentrated wastes
7/23/2019 Biological Treatment of Wastewater
http://slidepdf.com/reader/full/biological-treatment-of-wastewater 9/16
100
60
30
10
100
20
60
20
Efficiency: 90% 80%
7/23/2019 Biological Treatment of Wastewater
http://slidepdf.com/reader/full/biological-treatment-of-wastewater 10/16
FACTORS FOR IMPROVED EFFICIENCY
•
Availability of many MO• Better contact between MO and organic matter
• Favorable environmental conditions
(Temperature, pH, nutrient requirement, retentiontime…)
• Availability of oxygen for aerobic treatment process
7/23/2019 Biological Treatment of Wastewater
http://slidepdf.com/reader/full/biological-treatment-of-wastewater 11/16
BIO-KINETIC COEFFICIENTS/ GROWTH CONSTANTS
Understanding the kinetics of,
• Microbial growth rate
• Substrate utilization rate
• Limiting substrate or nutrients
• Endogenous decay or death rate of MO
7/23/2019 Biological Treatment of Wastewater
http://slidepdf.com/reader/full/biological-treatment-of-wastewater 12/16
The growth curve of MO
7/23/2019 Biological Treatment of Wastewater
http://slidepdf.com/reader/full/biological-treatment-of-wastewater 13/16
Ex: Specific growth rate, µ
Yield coefficient, Y
Maximum substrate utilization rate, K
Net specific growth rate,r’
g
Hydraulic retention time (HRT), θ
Cell retention time (SRT), θc
7/23/2019 Biological Treatment of Wastewater
http://slidepdf.com/reader/full/biological-treatment-of-wastewater 14/16
• Biomass concentration in the reactor, X
• Substrate concentration, S
• Rate of growth, rg
• Maximum specific growth rate of biomass, µmax
• Half velocity constant, Ks
• Substrate utilization rate, rsu
• Endogenous decay coefficient, Kd
• Rate of endogenous decay of biomass, rd
•
Observed yield coefficient, Yobs
7/23/2019 Biological Treatment of Wastewater
http://slidepdf.com/reader/full/biological-treatment-of-wastewater 15/16
KINETICS TO BIOLOGICAL TREATMENT
• Prediction of effluent biomass and substrate
concentrations
• Prediction of bio-kinetic coefficients
• Kinetics to activated sludge biological treatment
process
7/23/2019 Biological Treatment of Wastewater
http://slidepdf.com/reader/full/biological-treatment-of-wastewater 16/16
Cont.
• Biological nitrification
• Biological denitrification
• Biological mechanism of phosphorous removal