TY - JOUR
T1 - Modeling biofilm dynamics and hydraulic properties in variably saturated soils using a channel network model
AU - Rosenzweig, Ravid
AU - Furman, Alex
AU - Dosoretz, Carlos
AU - Shavit, Uri
PY - 2014/7
Y1 - 2014/7
N2 - Biofilm effects on water flow in unsaturated environments have largely been ignored in the past. However, intensive engineered systems that involve elevated organic loads such as wastewater irrigation, effluent recharge, and bioremediation processes make understanding how biofilms affect flow highly important. In the current work, we present a channel-network model that incorporates water flow, substrate transport, and biofilm dynamics to simulate the alteration of soil hydraulic properties, namely water retention and conductivity. The change in hydraulic properties due to biofilm growth is not trivial and depends highly on the spatial distribution of the biofilm development. Our results indicate that the substrate mass transfer coefficient across the water-biofilm interface dominates the spatiotemporal distribution of biofilm. High mass transfer coefficients lead to uncontrolled biofilm growth close to the substrate source, resulting in preferential clogging of the soil. Low mass transfer coefficients, on the other hand, lead to a more uniform biofilm distribution. The first scenario leads to a dramatic reduction of the hydraulic conductivity with almost no change in water retention, whereas the second scenario has a smaller effect on conductivity but a larger influence on retention. The current modeling approach identifies key factors that still need to be studied and opens the way for simulation and optimization of processes involving significant biological activity in unsaturated soils. Key Points A pore network was used to simulate coupled water flow and biofilm dynamics Mass transfer at the water-biofilm interface controls biofilm dynamics High mass transfer coefficient leads to severe clogging
AB - Biofilm effects on water flow in unsaturated environments have largely been ignored in the past. However, intensive engineered systems that involve elevated organic loads such as wastewater irrigation, effluent recharge, and bioremediation processes make understanding how biofilms affect flow highly important. In the current work, we present a channel-network model that incorporates water flow, substrate transport, and biofilm dynamics to simulate the alteration of soil hydraulic properties, namely water retention and conductivity. The change in hydraulic properties due to biofilm growth is not trivial and depends highly on the spatial distribution of the biofilm development. Our results indicate that the substrate mass transfer coefficient across the water-biofilm interface dominates the spatiotemporal distribution of biofilm. High mass transfer coefficients lead to uncontrolled biofilm growth close to the substrate source, resulting in preferential clogging of the soil. Low mass transfer coefficients, on the other hand, lead to a more uniform biofilm distribution. The first scenario leads to a dramatic reduction of the hydraulic conductivity with almost no change in water retention, whereas the second scenario has a smaller effect on conductivity but a larger influence on retention. The current modeling approach identifies key factors that still need to be studied and opens the way for simulation and optimization of processes involving significant biological activity in unsaturated soils. Key Points A pore network was used to simulate coupled water flow and biofilm dynamics Mass transfer at the water-biofilm interface controls biofilm dynamics High mass transfer coefficient leads to severe clogging
KW - biofilm
KW - pore network model
KW - soil hydraulic properties
UR - http://www.scopus.com/inward/record.url?scp=84904082780&partnerID=8YFLogxK
U2 - 10.1002/2013WR015211
DO - 10.1002/2013WR015211
M3 - 文章
AN - SCOPUS:84904082780
SN - 0043-1397
VL - 50
SP - 5678
EP - 5697
JO - Water Resources Research
JF - Water Resources Research
IS - 7
ER -