modern wastewater treatment
WASTEWATER
TREATMENT
Lili sugiyarto
Lili_sugiyarto@uny.ac.id
The primary goal
The
removal and degradation of organic
matter under controlled condition
Three major steps
Primary
treatment
Secondary treatment
Tertiary treatment
Primary treatment
A
physical process that involves the
separation of large debries, followed by
sedimentation
Comprises grit tank and settling tank
Settling tank also known as sedimentation
tank (sand and gravel)/clarifier
About half suspended organic solids settle
to the bottom as sludge or biosolids
(primary sludge)
Secondary treatment
Consist
of biological degradation
(decomposed and the number of
pathogens is reduced)
The effluent from primary treatment may
be pumped into a tricklingfilter bed ( an
aeration tank/a sewage lagoon
Disinfection step is generally included at
the end of treatment
Large-scale wastewater
treatment
Trickling filter bed
•
•
•
Rocks provide a matrix supporting the growth
of a microbial biofilm that actively degrades
the organic material under aerobic
conditions
Effluen from primary treatment is pumped into
a tank and mixed with bacteria-rich known as
activated sludge
air and pure oxygen pumped through the
mixture promotes bacterial growth and
decomposition of the organic material
Then goes to a secondary
settling tank
Water
siphon off the top of the tank
Sludge is removed from the bottom
Some of the sludge is used as an inoculum
for the incoming activated sludge
The sludge that is not return as secondary
sludge
Trickling filters
Gram
negative bacteria : Zooglea,
Pseudomonas, Alcaligenes,
Achromobacter, Flavobacterium
Gram positive : Corynebacterium, etc
Fungi : Fusarium, Trisporon, Ascoidea
In secondary treatment
It
contains a high level of the organic
nutrients phosphate and nitrate
Nitrosomonas : oxidize ammonia to nitrite
Nitrobacter : oxidize nitrite to nitrate
Secondary treatment
Aerobic
digestion tank
Anaerobic digestion tank
Anaerobic digestion tank
The
degradatif and fermentative process
divided into 2 stages : acid forming and
methane forming
Genera of Methane forming stage :
Methanobacterium, Methanosarcina,
Methanococcus (convert acetate,
hydrogen and CO2 to methane)
The major metabolic stages
Complex organic compounds
(polysaccharides, fats, protein)
Hydrolisis
Hydrolysis by extracellular bacterial enzymes
Monomeric compounds (sugar, fatty acids,
amino acids)
Higher organic acids
Acidogenesis
Acetic acid, H2, CO2
Acetogenesis
CH4
methanogenesis
Types of Bioremediation
In
situ bioremediation
Composting
Landfarming
Above-ground bioreactors
Activated sludge process
Activated sludge flocs
Note filamentous bacteria
Note Vorticella and
other protozoa
Activated sludge model
L
L0
L
L
L
L
Composition of sludge
© PK, 2006 page 21
Urban Water Systems
• Predominantly water
• Micro-organisms
• Viruses, pathogens, germs in general
• Organic particles, heavily bio-degradable
• Organic compounds, inert, adsorpted to sludge flocs
• Heavy metals
• Micro-pollutants, pharmaceuticals, endocrine disrupters
All non-degraded compounds extracted from wastewater are found in the
12 Sludge treatment
sludge
Activated sludge plants
Hyperion, Playa del Rey, CA)
Primary aeration tank
Tertiary treatment
Involve
some type of physicochemical
treatment such as coagulation, filtration,
activated carbon adsorbtion of organics
and additional disinfectan
© PK, 2006 page 25
Goals of sludge treatment
Urban Water Systems
Volume reduction
• Thickening
• Dewatering
Elimination of pathogenic
germs
• If used in agriculture as fertiliser or compost
Stabilisation of organic
substances
•
•
•
•
Recycling of substances
• Nutrients, fertiliser
• Humus
• Biogas
Gas production
Reduction of dry content
Improvement of dewatering
Reduction of odour
12 Sludge treatment
Overview
© PK, 2006 page 26
Urban Water Systems
Wastewater treatment
Process water
Primary, secondary, tertiary sludge
Thickening
Energy
Hygienisation
Stabilisation
Biogas
Thickening
Agriculture
Dewatering
Disposal site
Drying
Construction industry
12 Sludge treatment
Gujer (1999)
Incineration
Atmosphere
Oxygenated systems
Cryogenic air separation facility, Hyperion, Playa del Rey, CA)
Typical steps in modern wastewater
treatment
Flotation unit
© PK, 2006 page 29
Urban Water Systems
12 Sludge treatment
Examples of naturally
transmissible catabolic
plasmids
Primary
substrate
Plasmid
Size
(kb)
Host
Toluene
pWW0 (TOL)
117
Pseudomonas
putida mt-2
Alkylbenzene ASL
sulfonate
91.5
Pseudomonas
testosroni
octane
~500
P.oleovorans
83
P. Putida PpG7
OCT
Naphthalene Nah7
Pseudomonas putida mt-2
Chromosomal
gene encode ortho
pathway : acetyl CoA and succinate
TOL plasmid encodes meta pathway :
acetaldehide and pyruvic acid
TOL (pWW0) plasmid
The
genes encoding catabolic enzymes :
xyl genes
The Xyl genes : xyl ABC (upper) and xyl
XYZLEGFJKIH (lower/meta)
Xyl ABC
Encode
degradation toluene and xylene
to benzoate and metylbenzoates
Xyl XYZLEGFJKIH
Encodes
degradation of benzoate and
methylbenzoate to acetaldehyde and
pyruvat
TREATMENT
Lili sugiyarto
Lili_sugiyarto@uny.ac.id
The primary goal
The
removal and degradation of organic
matter under controlled condition
Three major steps
Primary
treatment
Secondary treatment
Tertiary treatment
Primary treatment
A
physical process that involves the
separation of large debries, followed by
sedimentation
Comprises grit tank and settling tank
Settling tank also known as sedimentation
tank (sand and gravel)/clarifier
About half suspended organic solids settle
to the bottom as sludge or biosolids
(primary sludge)
Secondary treatment
Consist
of biological degradation
(decomposed and the number of
pathogens is reduced)
The effluent from primary treatment may
be pumped into a tricklingfilter bed ( an
aeration tank/a sewage lagoon
Disinfection step is generally included at
the end of treatment
Large-scale wastewater
treatment
Trickling filter bed
•
•
•
Rocks provide a matrix supporting the growth
of a microbial biofilm that actively degrades
the organic material under aerobic
conditions
Effluen from primary treatment is pumped into
a tank and mixed with bacteria-rich known as
activated sludge
air and pure oxygen pumped through the
mixture promotes bacterial growth and
decomposition of the organic material
Then goes to a secondary
settling tank
Water
siphon off the top of the tank
Sludge is removed from the bottom
Some of the sludge is used as an inoculum
for the incoming activated sludge
The sludge that is not return as secondary
sludge
Trickling filters
Gram
negative bacteria : Zooglea,
Pseudomonas, Alcaligenes,
Achromobacter, Flavobacterium
Gram positive : Corynebacterium, etc
Fungi : Fusarium, Trisporon, Ascoidea
In secondary treatment
It
contains a high level of the organic
nutrients phosphate and nitrate
Nitrosomonas : oxidize ammonia to nitrite
Nitrobacter : oxidize nitrite to nitrate
Secondary treatment
Aerobic
digestion tank
Anaerobic digestion tank
Anaerobic digestion tank
The
degradatif and fermentative process
divided into 2 stages : acid forming and
methane forming
Genera of Methane forming stage :
Methanobacterium, Methanosarcina,
Methanococcus (convert acetate,
hydrogen and CO2 to methane)
The major metabolic stages
Complex organic compounds
(polysaccharides, fats, protein)
Hydrolisis
Hydrolysis by extracellular bacterial enzymes
Monomeric compounds (sugar, fatty acids,
amino acids)
Higher organic acids
Acidogenesis
Acetic acid, H2, CO2
Acetogenesis
CH4
methanogenesis
Types of Bioremediation
In
situ bioremediation
Composting
Landfarming
Above-ground bioreactors
Activated sludge process
Activated sludge flocs
Note filamentous bacteria
Note Vorticella and
other protozoa
Activated sludge model
L
L0
L
L
L
L
Composition of sludge
© PK, 2006 page 21
Urban Water Systems
• Predominantly water
• Micro-organisms
• Viruses, pathogens, germs in general
• Organic particles, heavily bio-degradable
• Organic compounds, inert, adsorpted to sludge flocs
• Heavy metals
• Micro-pollutants, pharmaceuticals, endocrine disrupters
All non-degraded compounds extracted from wastewater are found in the
12 Sludge treatment
sludge
Activated sludge plants
Hyperion, Playa del Rey, CA)
Primary aeration tank
Tertiary treatment
Involve
some type of physicochemical
treatment such as coagulation, filtration,
activated carbon adsorbtion of organics
and additional disinfectan
© PK, 2006 page 25
Goals of sludge treatment
Urban Water Systems
Volume reduction
• Thickening
• Dewatering
Elimination of pathogenic
germs
• If used in agriculture as fertiliser or compost
Stabilisation of organic
substances
•
•
•
•
Recycling of substances
• Nutrients, fertiliser
• Humus
• Biogas
Gas production
Reduction of dry content
Improvement of dewatering
Reduction of odour
12 Sludge treatment
Overview
© PK, 2006 page 26
Urban Water Systems
Wastewater treatment
Process water
Primary, secondary, tertiary sludge
Thickening
Energy
Hygienisation
Stabilisation
Biogas
Thickening
Agriculture
Dewatering
Disposal site
Drying
Construction industry
12 Sludge treatment
Gujer (1999)
Incineration
Atmosphere
Oxygenated systems
Cryogenic air separation facility, Hyperion, Playa del Rey, CA)
Typical steps in modern wastewater
treatment
Flotation unit
© PK, 2006 page 29
Urban Water Systems
12 Sludge treatment
Examples of naturally
transmissible catabolic
plasmids
Primary
substrate
Plasmid
Size
(kb)
Host
Toluene
pWW0 (TOL)
117
Pseudomonas
putida mt-2
Alkylbenzene ASL
sulfonate
91.5
Pseudomonas
testosroni
octane
~500
P.oleovorans
83
P. Putida PpG7
OCT
Naphthalene Nah7
Pseudomonas putida mt-2
Chromosomal
gene encode ortho
pathway : acetyl CoA and succinate
TOL plasmid encodes meta pathway :
acetaldehide and pyruvic acid
TOL (pWW0) plasmid
The
genes encoding catabolic enzymes :
xyl genes
The Xyl genes : xyl ABC (upper) and xyl
XYZLEGFJKIH (lower/meta)
Xyl ABC
Encode
degradation toluene and xylene
to benzoate and metylbenzoates
Xyl XYZLEGFJKIH
Encodes
degradation of benzoate and
methylbenzoate to acetaldehyde and
pyruvat