srb biofilm growth simulation: effect of sulfate concentration and fluid flow velocity

姓名：韩洋导师：康勇 教授

SRB Biofilm Growth Simulation: Effect of Sulfate Concentration and

Fluid Flow Velocity

Model Description

Simulation Strategy

X Induced Biofilm

Heterogeneity

How X Affect Biofilm

Heterogeneity

The Function of

Biofilm Structure

Sulfate Reduction Efficiency

Model Description

Simulation Domain

Model Description

Simulation Parameters

3.2 mm

0.8

mm

Model Description

Simulation Parameters

u(m/s)c(mg/l) 0.0001 0.001 0.00625 0.01 0.04

10 1 7 13 19 2518 2 8 14 20 2630 3 9 15 21 2745 4 10 16 22 2860 5 11 17 23 29

100 6 12 18 24 30

SRB Biofilm Heterogeneity

Effect of Sulfate Concentration (Low Re)

Sul

fate

Con

cent

ratio

n In

crea

ses

SRB Biofilm Heterogeneity

Effect of Sulfate Concentration (High Re)

Sul

fate

Con

cent

ratio

n In

crea

ses

SRB Biofilm Heterogeneity

Effect of Flow Velocity

SRB Biofilm Heterogeneity

Effect of Flow Velocity

Heterogeneity ParametersEffect of Sulfate Concentration

Heterogeneity ParametersEffect of Sulfate Concentration

Heterogeneity ParametersEffect of Flow Velocity

Heterogeneity ParametersEffect of Flow Velocity

Mass Transfer Parameters

Local Sherwood Number Sh

s h

s

k LSh

D

0( ) s

n s s s scJ k c c Dr

0

ss

ss s

cDrk

c c

0

- sh

s s

cLrSh

c c

Mass Transfer Parameters

Effect of Sulfate Concentration on Sh

Mass Transfer Parameters

Effect of Flow Velocity on Sh

Mass Transfer Parameters

Convection Flux vs. Diffusion Flux

2 2C S x yJ c u u

22

2 2S S

D Sc c

J Dx y

Mass Transfer Parameters

Convection Flux vs. Diffusion Flux

Flow

Vel

ocity

Incr

ease

s

Mass Transfer Parameters

Convection Flux vs. Diffusion Flux

Sul

fate

Con

cent

ratio

n In

crea

ses

Mass Transfer Parameters

Mass Transfer Within Biofilm

Mass Transfer ParametersMass Transfer Within Biofilm

Flow

Vel

ocity

Incr

ease

s

Mass Transfer ParametersMass Transfer Within Biofilm

Further Research 1

The function of Channels within SRB Biofilm

Pathway for Mass Transfer

Sulfate/Substrate

Sulfide/Other Production

Should mass transfer and biofilm growth be coupled?

Cavity Vortex

Mass Transfer

Sulfide Inhibition

Precipitation

Further Research 1

Total Sulfide Concentration Profile

Re = 0.08

Re = 8

Re = 32

Reaction Parameters

1 p S

Sh Sh dAA

( , )

d ( , )bb

reac S b S S zi j

Q r r c i j x yL

,reac

S Cx z

QL L

0 d

b

reac

S S b

Qr c

Reaction Parameters

Further Research 2

The Effect of Re on and

Further Research 3

Sensibility to Sulfate Concentration Limitation

Strategy For High Sulfate Concentration Simulation

Further Research 3

The Cause of Concentration sensibility - Limited Penetration Depth

Strategy For High Sulfate Concentration Simulation

Further Research 3

Limited Penetration Depth – Is it reasonable?

Strategy For High Sulfate Concentration Simulation

Further Research 3

Limited Penetration Depth – Microbial Reaction Intensity

Strategy For High Sulfate Concentration Simulation

𝜇𝑚=0.344h− 1

𝐾 𝑠=1.8 h𝑚𝑔 − 1

𝑌 𝑐𝑒𝑙𝑙 /𝑠𝑢𝑙=0.047

𝜇𝑚=0.061h−1

𝐾 𝑠=5 8 h𝑚𝑔 −1

𝑌 𝑐𝑒𝑙𝑙 /𝑠𝑢𝑙=0.567

𝑘𝑚=𝜇𝑚

𝑌 𝑐𝑋≈ 0.061𝑘𝑔𝑚− 3𝑠− 1 𝑘𝑚=𝜇𝑚

𝑌 𝑐 𝑋≈ 9.0×10− 4𝑘𝑔𝑚−3𝑠−1

𝑎=√ 2𝐷𝑐𝑠0

𝑘𝑚≈60𝜇𝑚 𝑎=√ 2𝐷𝑐𝑠0

𝑘𝑚≈486𝜇𝑚

√ √

√ √

Further Research 3

Limited Penetration Depth – Microbial Reaction Intensity

Strategy For High Sulfate Concentration Simulation

Further Research 3

Limited Penetration Depth – Maintenance Within The Bottom of Biofilm

Strategy For High Sulfate Concentration Simulation

Decay

Sulfate/Substrate Deficiency

Maintenance

Hydrolysis

Void Inert Biomass

Maintenance Product EPS Precipitation

Further Research 3

Limited Penetration Depth – Maintenance Within The Bottom of Biofilm

Strategy For High Sulfate Concentration Simulation

Decay

Hydrolysis

Void Inert Biomass

Maintenance Product EPS Precipitation

( , ) ( )m SS S X S X

XS S S

cr c c m c

Y c K

( , ) ( ( , ) )X S X XS S S X S Xr c c Y r c c m c

( , ) ( )Inh S X Inh X XS S Xr c c b c Y m c

S

Inh X

rR

b c

𝑅<𝑅𝑚𝑖𝑛

𝑟 h𝐼𝑛

Multi-species CA

Further Research n

Sulfide Inhibition• Does sulfide influence heterogeneity structure ?• Could SRB be inhibited by the sulfide produced by

themselves? • What factor influences the profile of different sulfide

species in biofilm? Precipitation

• CA or iBM: Should precipitation be modeled as individual particles or just a percentage of a controlled volume?

• Is there any interactive effect between sulfide, metal iron and SRB biofilm heterogeneity?