(Chapra, L26 & L29) David Reckhow CEE 577 #27 1 Mechanistic - - PowerPoint PPT Presentation

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Updated: 28 March 2013 Print version Lecture #27 Limnology (cont.): Other Mechanistic Models (Chapra, L26 & L29) David Reckhow CEE 577 #27 1 Mechanistic Nutrient Models Qual2E/Qual2K Rivers: 1 dimensional DOC compartments

SLIDE 1

Lecture #27 Limnology (cont.): Other Mechanistic Models

(Chapra, L26 & L29)

David Reckhow CEE 577 #27 1

Updated: 28 March 2013

Print version

SLIDE 2

Mechanistic Nutrient Models

 Qual2E/Qual2K

 Rivers: 1 dimensional  DOC compartments expanded in 2K – like WQMCB

 CE-QUAL-W2

 Reservoir, Estuary: 2 dimensional (longitudinal-vertical)

 Cannonsville Reservoir Model  WQDPM (Water Quality Diss. Part. Model)

 3 dimensional  Coupled to GLLVHT Hydrodynamics

 Generalized Longitudinal Lateral Vertical Hydrodynamic and

Transport model  11 constituents

 Separates Org-N and Org-C into dissolved and particulate

David Reckhow CEE 577 #27 2

SLIDE 3

General Qual2E Kinetics

David Reckhow CEE 577 #21 3

Dissolved Oxygen CBOD

K1 K3

Atmosphere

K2

Organic N

β3

SOD

K4

NH3 NO2 NO3

β

β2 α β

5 1

σ4 σ3

(Ks) (Ka) (Kd) Chlorophyll a

(Algae)

Org-P Diss-P

α µ

1 F

α µ

1 ( ) − F

α µ

α ρ

α µ

α ρ

β4

σ5 σ2

σ1

2 6β

α

SLIDE 4

Qual2K version

David Reckhow CEE 577 #27 4

dn u

pi po

h e d s s s sod cf re se se se se s s

mi s Alk

na no

nn cf

rod rda rna rpa

IN IP

p r s u e

dn u

pi po

h e d s s s sod cf re se se se se s s

mi s Alk

na no

nn cf

rod rda rna rpa

IN IP

p r s u e

Kinetic processes are dissolution (ds), hydrolysis (h), oxidation (ox), nitrification (n), denitrification (dn), photosynthesis (p), respiration (r), excretion (e), death (d), respiration/excretion (rx). Mass transfer processes are reaeration (re), settling (s), sediment oxygen demand (SOD), sediment exchange (se), and sediment inorganic carbon flux (cf)

SLIDE 5

Q2K state Variables

David Reckhow CEE 577 #27 5 Variable Symbol Units* Conductivity

µmhos Inorganic suspended solids

mgD/L Dissolved oxygen

mgO2/L

Slowly reacting CBOD

mgO2/L Fast reacting CBOD

mgO2/L Organic nitrogen

µgN/L Ammonia nitrogen

µgN/L Nitrate nitrogen

µgN/L Organic phosphorus

µgP/L Inorganic phosphorus

µgP/L Phytoplankton

µgA/L Phytoplankton nitrogen

INp

µgN/L Phytoplankton phosphorus

IPp

µgP/L Detritus

mgD/L Pathogen

cfu/100 mL Total inorganic carbon

mole/L Bottom algae biomass

mgA/m2 Bottom algae nitrogen

INb

mgN/m2 Bottom algae phosphorus

IPb

mgP/m2

D, C, N, P, and A refer to dry weight, carbon, nitrogen, phosphorus, and chlorophyll a, respectively

Note:

fast and slow CBOD
dissolved P is now inorganic P
nitrite is dropped

SLIDE 6

Q2K Sediment Model

David Reckhow CEE 577 #27 6 CH4 NO3 NO3 NH4d PO4p PO4d NH4p NH4d PO4p PO4d CO2 N2 N2 POC

nn pi

Jpom

NH4p CH4(gas) POP DIAGENESIS METHANE AMMONIUM NITRATE PHOSPHATE AEROBIC ANAEROBIC WATER PON

“Organic carbon, nitrogen and phosphorus are delivered to the anaerobic sediments via the settling of particulate

rganic matter (i.e.,

phytoplankton and detritus). There they are transformed by mineralization reactions into dissolved methane, ammonium and inorganic

phosphorus. These

constituents are then transported to the aerobic layer where some of the methane and ammonium are

xidized. The flux of oxygen

from the water required for these oxidations is the sediment oxygen demand.” “The sediments are divided into 2 layers: a thin (≅ 1 mm) surface aerobic layer underlain by a thicker (10 cm) lower anaerobic layer.”

From Chapra, Pelletier & Tao, 2008

SLIDE 7

Cannonsville Model

David Reckhow CEE 577 #27 7

Phosphorus Nitrogen Phytoplankton Zooplankton Dissolved O2

SLIDE 8

WQDPM Model

David Reckhow CEE 577 #27 8

From: Edinger, 2002, Waterbody Hydrodynamic and Water Quality Modeling, ASCE Press

SLIDE 9

WQDPM Model

David Reckhow CEE 577 #27 9

From: Edinger, 2002, Waterbody Hydrodynamic and Water Quality Modeling, ASCE Press

SLIDE 10

Higher-Order Carbon Model

 WQMCB

 Expands organic carbon fractions –

 adopted for use by new QUAL2K visual basic version

 Fast-reacting (dissolved and particulate)  Slow-reacting (dissolved and particulate)  Refractory (particulate only)

 14 constitutents

David Reckhow CEE 577 #27 10

SLIDE 11

WQMCB model

David Reckhow CEE 577 #27 11

From: Edinger, 2002, Waterbody Hydrodynamic and Water Quality Modeling, ASCE Press

SLIDE 12

WQMCB model

David Reckhow CEE 577 #27 12

From: Edinger, 2002, Waterbody Hydrodynamic and Water Quality Modeling, ASCE Press

SLIDE 13

 To next lecture

David Reckhow CEE 577 #27 13