1 / 46

# CE421 - PowerPoint PPT Presentation

CE421/521 Environmental Biotechnology. Nitrogen and Phosphorus Cycles Lecture 9-26-06 Tim Ellis. Nitrification Kinetics. where μ max = maximum specific growth rate, h-1 K S = half saturation coefficient for ammonia, mg/L as NH 4 -N K O = half saturation coefficient, mg/L as O2

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.

## PowerPoint Slideshow about 'CE421' - loren

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

### CE421/521 Environmental Biotechnology

Nitrogen and Phosphorus Cycles

Lecture 9-26-06

Tim Ellis

where

μmax = maximum specific growth rate, h-1

KS = half saturation coefficient for ammonia, mg/L as NH4-N

KO = half saturation coefficient, mg/L as O2

Yield = mg biomass formed/mg ammonia utilized

• d____________ o_____________

• t______________

• p___

• i_____________________

where I = concentration of inhibitor, mg/L

KI = inhibition coeficient, mg/L

• derivation of the

• A____________ equation

• where k1,2 = reaction rate coefficient at temperature T1,2

• θ = t___________ c__________

ln θ

ln k

Temp (deg C or K)

• given the following measured data, calculate the theta value

1. A_____________________ nitrate reduction: NO3- ➔ NH4+ nitrate is incorporated into cell material and reduced inside the cell

2. D___________________ nitrate reduction (denitrification)

• NO3- serves as the t____________ e_______________ a_________________ (TEA) in an anoxic (anaerobic) environment

nitrate reductase nitrite r. nitric oxide r. nitrous oxide r.

NO3- ➔ NO2- ➔ NO ➔ N2O ➔ N2

summarized as:

NO3- ➔ NO2- ➔ N2

• requires o______________ m________________(example: methanol)

• kinetics for denitrification similar to those for heterotrophic aerobic growth

6NO3- + 5CH3OH ➔ 3N2 + 5 CO2 + 7 H2O + 6 OH-

• calculate COD of methanol:

• calculate alkalinity:

• Total Kjeldahl Nitrogen (TKN) = o___________ n___________ + a______________

• (measured by digesting sample with sulfuric acid to convert all nitrogen to ammonia)

• TKN ~ 35 mg/L in influent

• p____________ t____________ removes approximately 15%

• additional removal with biomass w______________

• Biological

• n_______________

• d________________

• ANAMMOX: ammonium is the electron donor, nitrite is the TEA

NH4+ + NO2- ➔ N2 + 2 H2O

Suitable for high ammonia loads (typically greater than 400 mg/L) and low organic carbon

• Chemical/Physical

• air s_______________

• breakpoint c__________________

• ion e_____________________

• reverse o___________________

1. T________________

2. D________________ of DO

3. E__________________________

4. Nitrate in d________________ water – causes methemoglobinemia (blue baby) oxidizes hemoglobin to methemoglobin

• Completely mixed activated sludge (CMAS)

• Conventional activated sludge (CAS)

• Sequencing Batch Reactor (SBR)

• Extended aeration, oxidation ditch, others

Treatment Plant

Influent

Force

Main

Activated Sludge

Aeration Basin

Bar Rack/

Screens

Primary

Settling Tank

Grit

Tank

Diffusers

Screenings

Grit

Air or Oxygen

Primary

Sludge

Secondary

Settling Tank

Waste Activated Sludge (WAS)

Cl2

Tertiary

Filtration

(Optional)

to

receiving

stream

Chlorine Contact Basin

(optional)

wastewater flow

Return Activated

Sludge (RAS)

residuals flow

to tertiary treatment

or surface discharge

clarifier

aeration basin

air or

oxygen

RAS

WAS

Primary effl.

plan view

to secondary clarifier

RAS

Feed

Feed

RAS

High

F/M

Selector

Low F/M

CMAS with Selector

Contact Stabilization Activated Sludge

clarifier

aeration basin

air or

oxygen

contact

tank

RAS

WAS

air or

oxygen

WASTEWATER

AIR

TREATED

EFFLUENT

Sludge wastage at end

of decant cycle

FILL

REACT

SETTLE

DECANT

• limiting n___________________ in algae (at approximately 1/5 the nitrogen requirement)

• 15% of population in US discharges to l_________________

• wastewater discharge contains approximately 7- 10 mg/L as P

• o__________________

• i______________: orthophosphate

• Chemical precipitation:

Al+3 + PO4-3 ➔ AlPO4

Fe+3 + PO4-3 ➔ FePO4

• as s_______________ (magnesium ammonium phosphate, MAP)

Mg+2 + NH4+ + PO4-3 ➔ MgNH4PO4

• Scale build-up chokes pipelines, clogs aerators, reduces heat exchange capacity

• Canned king crab industry

• Kidney stones

• Nonburning and long lasting source of nitrogen and phosphorus

• Found in natural fertilizers such as guano

• Heavy applications have not burned crops or depressed seed germination (Rothbaum, 1976)

• Used for high-value crops

For ISU study on removing ammonia from hog waste see:

www.public.iastate.edu/~tge/miles_and_ellis_2000.pdf

• 2300 head operation in central Iowa, USA

• methane recovery for energy generation

• site for full-scale study for struvite precipitation

• Discovered in plug flow A.S. systems

• Requires anaerobic (low DO and NO3-) zone and aerobic zone

• Biological “battery”

• Grow phosphate accumulating organisms (PAO) with 7% P content

• Need to remove TSS

• Uptake of acetic acid

• Storage polymer (PHB) is formed

• Polyphosphate granule is consumed

• Phosphate is released

• Energy (ATP) is regenerated as bacteria consume BOD

• Phosphorus is taken into the cell and stored as poly-P granule

• When BOD is depleted, PAO continue to grow on stored reserves (PHB) and continue to store poly-P

H3CCOOH

H3CCOO- + H+

ATP

PHB

polymer

ATP

Pi

Pi

Polyphosphate

Granule

H+

ATP

H3CCOOH

H3CCOO- + H+

ATP

PHB

polymer

ATP

Pi

Polyphosphate

Granule

Pi

H+

ATP

substrate

H+

substrate

ATP

ATP

Polyphosphate

Granule

PHB

polymer

Pi

H2O

Pi

ATP

2H+ + 1/2O2

H+

H+

ATP

PHB

polymer

ATP

Polyphosphate

Granule

Pi

H2O

Pi

ATP

2H+ + 1/2O2

H+

• Need adequate supply of acetic acid

• Nitrate recycled in RAS will compete for acetic acid

• May need a trim dose of coagulant to meet permit

• Subsequent sludge treatment may return soluble phosphorus to A.S.

Alum, Fe+3 (optional)

air

Anaerobic

Selector

Secondary

Clarifier

Aeration Basin

return activated sludge (RAS)

waste activated

sludge (WAS)

Phosphate Storage “Battery”

• Competition between bio-P and denitrification

• BOD becomes valuable resource

• required for both N and P removal

• Operation depends on treatment goals

• One reaction will limit

• difficult to eliminate all BOD, N, and P

• Commercial models (BioWin, ASIM, etc.) useful to predict performance

nitrate rich recirculation

Secondary

Settling

Tank

Anaerobic

Selector

Anoxic

Selector

Aeration Basin

(nitrification zone)

air

return activated sludge (RAS)

waste activated

sludge (WAS)

A2O

nitrate rich recirculation

Secondary

Settling

Tank

Anaerobic

Selector

Secon-

dary

Aeration

Basin

Anoxic

Tank

Anoxic

Selector

Primary

Aeration Basin

air

air

return activated sludge (RAS)

waste activated

sludge (WAS)

5-Stage Bardenpho

nitrate rich recirculation

nitrate free recirculation

Secondary

Settling

Tank

Aeration Basin

First

Anoxic

Tank

Anaerobic

Selector

Second

Anoxic

Tank

air

return activated sludge (RAS)

waste activated

sludge (WAS)

Modified UCT

nitrate free

recirculation

nitrate rich recirculation

Secondary

Settling

Tank

Anoxic

Selector

Anaerobic

Selector

Aeration Basin

(nitrification zone)

air

return activated sludge (RAS)

waste activated

sludge (WAS)

Virginia Initiative Plant (VIP)

• inorganic: SO4-2 S° H2S

• organic: R — O — SO3-2

four key reactions:

• H2S o__________________ — can occur aerobically or anaerobically to elemental sulfur (S°)

• a___________________ : Thiobaccilus thioparus oxidizes S-2 to S°

• S-2 + ½ O2 + 2H+ ➔ S° + H2O

• a_______________________: — phototrophs use H2S as electron donor

• filamentous sulfur bacteria oxidize H2S to S° in sulfur granules: Beggiatoa, Thiothrix

2. Oxidation of E_______________ Sulfur (Thiobacillus thiooxidans at low pH)

2S° + 3 O2 + 2 H2O ➔ 2 H2SO4

3. A_______________________ sulfate reduction: proteolytic bacteria breakdown organic matter containing sulfur (e.g. amino acids: methionine, cysteine, cystine)

4. D_______________________ sulfate reduction: under anaerobic conditions

— s_____________ r________________ b_________________ (SR

SO4-2 + Organics ➔ S-2 + H2O + CO2

S-2 + 2H+ ➔ H2S

• Desulvibrio and others

• Sulfate is used as a TEA & l_____ m____________ w___________ organics serve as the electron donors

• Low cell y_______________

• P___________________ of SRB depends on COD:S ratio, particularly readily degradable (e.g., VFA) COD

• SRB compete with m_____________________ for substrate: high COD:S favors methanogens, low COD:S favors SRB