NORWEGIAN UNIVERSITY OF LIFE SCIENCES

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THT282 Introduction to sustainable water and
sanitation
Water treatment processes
Department of Plant and Environmental Sciences
P.D. Jenssen
NORWEGIAN UNIVERSITY OF LIFE SCIENCES

• Petter D. Jenssen and Manoj Pandey
• Professor, Norwegian University of Life
  Sciences (UMB)
• Assistant professor, Tribhuvan University,
  Nepal

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90 of the worlds wastewater does not receive
any treatment (Corcoran et al. 2010)
Department of Plant and Environmental Sciences,
P.D. Jenssen
NORWEGIAN UNIVERSITY OF LIFE SCIENCES
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Department of Plant and Environmental Sciences
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Phosphorus is the major agent triggering
eutrophication (algeal blooms) in freshwaters
Department of Plant and Environmental Sciences
P.D. Jenssen
NORWEGIAN UNIVERSITY OF LIFE SCIENCES
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The North Sea
Nitrogen is considered the main element
triggering eutrophication in saltwater
NORWEGIAN UNIVERSITY OF LIFE SCIENCES
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Photo R. Gjørven
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Department of Plant and Environmental Sciences
P.D. Jenssen
NORWEGIAN UNIVERSITY OF LIFE SCIENCES
Green algae in a stream in Norway at 1200 meters
altitude
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Nitrogen can cause algea growth in freshwater in
alpine regions
Department of Plant and Environmental Sciences
P.D. Jenssen
NORWEGIAN UNIVERSITY OF LIFE SCIENCES
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Kathmandu, Nepal
Dry season
Department of Plant and Environmental Sciences
P.D. Jenssen
NORWEGIAN UNIVERSITY OF LIFE SCIENCES

• DO less than 1 mg/l
• BOD - 250 mg

(Pandey et al. 2005)
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Putrification
Kathmandu, Nepal
Dry season
Department of Plant and Environmental Sciences
P.D. Jenssen
NORWEGIAN UNIVERSITY OF LIFE SCIENCES

• DO less than 1 mg/l
• BOD - 250 mg

(Pandey et al. 2005)
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Wastewatertreatment -removal parameters
Department of Plant and Environmental Sciences,
P.D. Jenssen
NORWEGIAN UNIVERSITY OF LIFE SCIENCES

• The objectives of sewage treatment will always
  include the reduction of the concentration of at
  least one of the below constituents
• Suspended solids
• Organic (biodegradable) material
• Nutrients (nitrogen and phosphorous)
• Pathogenic organisms (expressed as E. Coli)
• Medicine residues, organic chemicals (POPs)
• Heavy metals

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Methods of Removal

• The contaminants in wastewater are removed by
  different unit processes
• Physical (sedimetation, flotation, screening,
  filtration)
• Biological (trickling filters, RBC, activated
  sludge)
• Chemical (chemical precipitation, ozonation,
  chlorination)

Department of Plant and Environmental Sciences,
P.D. Jenssen
NORWEGIAN UNIVERSITY OF LIFE SCIENCES
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Wastewater Treatment Processes
Primary
Secondary
Tertiarary
Remove organics and ammonia
Remove nutrients and pathogens
Department of Plant and Environmental Sciences,
P.D. Jenssen
NORWEGIAN UNIVERSITY OF LIFE SCIENCES
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Sludge treatment
www.umb.no
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Methods of Removal

• Physical Unit Processes (mainly primary)
• Treatment methods in which the application of
  physical forces predominates are known as
  physical unit operations. Typical unit operations
  are
• Screening
• Sedimentation
• Floatation
• Membrane filtration (lt 1um)
• Tertiary treatment

Department of Plant and Environmental Sciences,
P.D. Jenssen
NORWEGIAN UNIVERSITY OF LIFE SCIENCES
Salsnes filter
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Membrane Filter Technology (tertiary)

• Sette inn egne bilder av membraner

Department of Plant and Environmental Sciences,
P.D. Jenssen
NORWEGIAN UNIVERSITY OF LIFE SCIENCES
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Membrane Filter Technology
Department of Plant and Environmental Sciences,
P.D. Jenssen
NORWEGIAN UNIVERSITY OF LIFE SCIENCES
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Wastewater Treatment Processes
Primary
Secondary
Tertiarary
Remove organics and ammonia
Remove nutrients and pathogens
Department of Plant and Environmental Sciences,
P.D. Jenssen
NORWEGIAN UNIVERSITY OF LIFE SCIENCES
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Sludge treatment
www.umb.no
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Methods of Removal (Contd.)

• Biological Unit Processes (mainly secondary)
• The treatment method in which the removal of
  contaminants is brought about by biological
  activity are known as biological unit process.
  Some examples are
• aerobic processes - presence of dissolved oxygen
• Biofilters
• Trickling filters
• Activated sludge
• anaerobic processes absence of dissolved oxygen
• Denitrification (tertiary)
• Septic tanks
• Ponds

Department of Plant and Environmental Sciences,
P.D. Jenssen
NORWEGIAN UNIVERSITY OF LIFE SCIENCES
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www.umb.no
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Biofilter Porous media
LWA Diam 2,5 mm
Surface area gt 5000m2/m3
Bacteria on LWA surface
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Wastewater spraying over a biofilter
Department of Plant and Environmental Sciences,
P.D. Jenssen
NORWEGIAN UNIVERSITY OF LIFE SCIENCES
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Biofilter trickling filter (fixed biofilm)
Department of Plant and Environmental Sciences,
P.D. Jenssen
NORWEGIAN UNIVERSITY OF LIFE SCIENCES
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Biofilter Rotating biological contactor - RBC
(fixed biofilm)
Department of Plant and Environmental Sciences,
P.D. Jenssen
NORWEGIAN UNIVERSITY OF LIFE SCIENCES
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Biological treatment Activated sludge (biofilm
in suspension)
Department of Plant and Environmental Sciences,
P.D. Jenssen
NORWEGIAN UNIVERSITY OF LIFE SCIENCES
Activated sludge at Ryaverket Gothenburg 700 000
pe
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Wastewater Treatment - Processes
Primary
Secondary
Tertiarary
Remove organics and ammonia
Remove nutrients and pathogens
Department of Plant and Environmental Sciences,
P.D. Jenssen
NORWEGIAN UNIVERSITY OF LIFE SCIENCES
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Sludge treatment
www.umb.no
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Methods of Removal (Contd.)

• Chemical Unit Process (tertiary)
• Treatment methods in which the removal or
  conversion of contaminants is brought about by
  the addition of chemicals or by chemical
  reactions are known as chemical unit processes.
  Some of the most common are
• Precipitation (lime, Fe- of Al salts, Struvite
  formation)
• Adsorption
• Disinfection

Department of Plant and Environmental Sciences,
P.D. Jenssen
NORWEGIAN UNIVERSITY OF LIFE SCIENCES
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www.umb.no
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Methods of Removal (Contd.)

• Chemical Unit Process (tertiary)
• Treatment methods in which the removal or
  conversion of contaminants is brought about by
  the addition of chemicals or by chemical
  reactions are known as chemical unit processes.
  Some of the most common are
• Precipitation
• Adsorption (Ion exchange)
• Disinfection

Department of Plant and Environmental Sciences,
P.D. Jenssen
NORWEGIAN UNIVERSITY OF LIFE SCIENCES
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www.umb.no
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Methods of Removal (Contd.)

• Chemical Unit Process (tertiary)
• Treatment methods in which the removal or
  conversion of contaminants is brought about by
  the addition of chemicals or by chemical
  reactions are known as chemical unit processes.
  Some of the most common are
• Precipitation
• Adsorption
• Disinfection (chlorination, UV-light, Ozone)

Department of Plant and Environmental Sciences,
P.D. Jenssen
NORWEGIAN UNIVERSITY OF LIFE SCIENCES
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www.umb.no
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Water and sludge treatment process at Bekkelaget
PAX-18
Precipitation
Primary
1900 l/sltQlt 4000 l/s
Qlt1900 l/s
Department of Plant and Environmental Sciences,
P.D. Jenssen
NORWEGIAN UNIVERSITY OF LIFE SCIENCES
Q1900 l/s
Biogas- upgrading
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Removal efficiency
Parameter Primary Secondary Tertiary
SS 50 - 80 80 - 90 gt90
BOD 20 - 40 70 - 90 gt90
P lt10 30 gt90
N lt10 30 70
E. Coli 1 log 2 -3 log 3 - 5 (7) logs
Department of Plant and Environmental Sciences,
P.D. Jenssen
NORWEGIAN UNIVERSITY OF LIFE SCIENCES
with disinfection
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