Impacts of stratigraphic heterogeneity and release pathway on the transport of bacterial cells in porous media

A two-way coupled model for the co-transport of two different colloids in porous media

“…Predicting the transport behaviour of colloidal contaminants such as pathogenic microorganisms and engineered nanoparticles in the subsurface is essential for the assessment of groundwater contamination risks (Ron and Johnson, 2020;Schijven and Hassanizadeh, 2002;Schijven et al, 2010), to estimate the safe distance of drinking water wells from (potential) contamination sources (Schijven et al, 2006), to decide on the degree of treatment required before supplying the groundwater for drinking purposes (Schijven et al, 1999(Schijven et al, , 2000, and to remediate contaminated groundwater (Malakar and Snow, 2020). It is found that the release pathways of colloidal contaminants, including point sources (such as deep well injection for bioremediation) and distributed sources (e.g., rainfall events, landfills, irrigation activities), have a significant impact on their fate and transport in the subsurface (Mahmoudi et al, 2020). There are also colloids that do not really pose any groundwater quality threats, but may act as carriers of contaminating colloids.…”

Key factors controlling microbial distribution on a DNAPL source area

“…The subsoil is a heterogeneous medium with many fluctuating parameters that affect the growth and survival of microorganisms (Paul and Clark 1989 ). Geological factors, such as pore size and the interconnectivity of the sediments (Puigserver et al 2020 ; Mahmoudi et al 2020 ), as well as the biogeochemical composition of the sediments, such as the content and composition of the organic matter and the presence of metals (Van Horn et al 2013 ), control the variation in the microbial communities across the subsurface environments. In saturated zones, the velocity, hydrochemical parameters, and temperature of the groundwater, as well as the composition of the planktonic microbial communities, also affect the structure of the microbial communities along the sediment (Velasco Ayuso et al 2009 ; Guo et al 2019 ).…”

Key Factors Controlling Microbial Distribution on a DNAPL Source Area

“…The subsoil is a heterogeneous medium with many uctuating parameters that affect the growth and survival of microorganisms (Paul and Clark 1989). Geological factors, like pore size and the interconnectivity of the sediments (Puigserver et al 2020;Mahmoudi et al 2020), and the biogeochemical composition of the sediments, like the content and composition of the organic matter and the presence of metals (Van Horn et al 2013), control the variation in the microbial communities across the subsurface environments. In saturated zones, the velocity, hydrochemical parameters and temperature of the groundwater, as well as the composition of the planktonic microbial communities, also affect structure of the microbial communities along the sediment (Velasco Ayuso et al 2009; Guo et al 2019).…”