Colloidal transport of heavy metals in low‐advective‐velocity environmental systems: Reactive transport model on biogeochemical and hydrodynamic impacts

Abstract In this study, the impact of colloid facilitated transport of heavy metals on the overall biogeochemical processes is demonstrated in example Lake Coeurd'Alene sediments. Release and transport of heavy metals (Pb and Zn) on initially sorbed colloidal Fe (hydr)oxide minerals are compare...

Full description

Bibliographic Details
Main Authors: S. Sevinç Şengör, Kahraman Ünlü
Format: Article
Language:English
Published: Wiley 2023-01-01
Series:Vadose Zone Journal
Online Access:https://doi.org/10.1002/vzj2.20233
_version_ 1797946577671684096
author S. Sevinç Şengör
Kahraman Ünlü
author_facet S. Sevinç Şengör
Kahraman Ünlü
author_sort S. Sevinç Şengör
collection DOAJ
description Abstract In this study, the impact of colloid facilitated transport of heavy metals on the overall biogeochemical processes is demonstrated in example Lake Coeurd'Alene sediments. Release and transport of heavy metals (Pb and Zn) on initially sorbed colloidal Fe (hydr)oxide minerals are compared with immobile surfaces under various advective flow velocities. The reactive transport model integrates a coupled biotic reaction network with multiple terminal electron acceptors, including multicomponent diffusion and electrostatic double layer (EDL) treatment effects, illustrating the impact of colloidal transport under competing biogeochemical reaction dynamics for the first time to the authors’ knowledge. The model results illustrate the sensitivity of the results under low‐flow‐velocity conditions. Although enhanced Fe reduction prevails with immobile Fe (hydr)oxide mineral surfaces, the desorbed metal ions with aqueous sulfide complexes are rather “washed out” from the system along with advective transport of solutes, whereas the reductive dissolution of colloidal Fe (hydr)oxides from freshly coming colloidal surfaces results in the accumulation of metal and sulfide ions in the system. The results show that when the potential transport of sorbed contaminants with colloidal particles are ignored, the contaminant concentrations might be underestimated under low‐flow‐velocity conditions, especially around 10−8 or 10−9 m s−1, where the underestimation for the worst case scenario at the lowest bound of low‐flow‐velocity conditions may reach around 90% with depth. On the other hand, this impact may be less significant under cases of higher flow velocity, even around higher limits of low‐velocity environments around 10−7 m s−1, as well as in pure diffusive transport cases.
first_indexed 2024-04-10T21:13:13Z
format Article
id doaj.art-81b2bbdc8b4c4d37bbd4cf7a2d661ccf
institution Directory Open Access Journal
issn 1539-1663
language English
last_indexed 2024-04-10T21:13:13Z
publishDate 2023-01-01
publisher Wiley
record_format Article
series Vadose Zone Journal
spelling doaj.art-81b2bbdc8b4c4d37bbd4cf7a2d661ccf2023-01-20T14:18:54ZengWileyVadose Zone Journal1539-16632023-01-01221n/an/a10.1002/vzj2.20233Colloidal transport of heavy metals in low‐advective‐velocity environmental systems: Reactive transport model on biogeochemical and hydrodynamic impactsS. Sevinç Şengör0Kahraman Ünlü1Dep. of Environmental Engineering Middle East Technical Univ. Dumlupınar Bulvarı No. 1 Ankara 06800 TurkeyDep. of Environmental Engineering Middle East Technical Univ. Dumlupınar Bulvarı No. 1 Ankara 06800 TurkeyAbstract In this study, the impact of colloid facilitated transport of heavy metals on the overall biogeochemical processes is demonstrated in example Lake Coeurd'Alene sediments. Release and transport of heavy metals (Pb and Zn) on initially sorbed colloidal Fe (hydr)oxide minerals are compared with immobile surfaces under various advective flow velocities. The reactive transport model integrates a coupled biotic reaction network with multiple terminal electron acceptors, including multicomponent diffusion and electrostatic double layer (EDL) treatment effects, illustrating the impact of colloidal transport under competing biogeochemical reaction dynamics for the first time to the authors’ knowledge. The model results illustrate the sensitivity of the results under low‐flow‐velocity conditions. Although enhanced Fe reduction prevails with immobile Fe (hydr)oxide mineral surfaces, the desorbed metal ions with aqueous sulfide complexes are rather “washed out” from the system along with advective transport of solutes, whereas the reductive dissolution of colloidal Fe (hydr)oxides from freshly coming colloidal surfaces results in the accumulation of metal and sulfide ions in the system. The results show that when the potential transport of sorbed contaminants with colloidal particles are ignored, the contaminant concentrations might be underestimated under low‐flow‐velocity conditions, especially around 10−8 or 10−9 m s−1, where the underestimation for the worst case scenario at the lowest bound of low‐flow‐velocity conditions may reach around 90% with depth. On the other hand, this impact may be less significant under cases of higher flow velocity, even around higher limits of low‐velocity environments around 10−7 m s−1, as well as in pure diffusive transport cases.https://doi.org/10.1002/vzj2.20233
spellingShingle S. Sevinç Şengör
Kahraman Ünlü
Colloidal transport of heavy metals in low‐advective‐velocity environmental systems: Reactive transport model on biogeochemical and hydrodynamic impacts
Vadose Zone Journal
title Colloidal transport of heavy metals in low‐advective‐velocity environmental systems: Reactive transport model on biogeochemical and hydrodynamic impacts
title_full Colloidal transport of heavy metals in low‐advective‐velocity environmental systems: Reactive transport model on biogeochemical and hydrodynamic impacts
title_fullStr Colloidal transport of heavy metals in low‐advective‐velocity environmental systems: Reactive transport model on biogeochemical and hydrodynamic impacts
title_full_unstemmed Colloidal transport of heavy metals in low‐advective‐velocity environmental systems: Reactive transport model on biogeochemical and hydrodynamic impacts
title_short Colloidal transport of heavy metals in low‐advective‐velocity environmental systems: Reactive transport model on biogeochemical and hydrodynamic impacts
title_sort colloidal transport of heavy metals in low advective velocity environmental systems reactive transport model on biogeochemical and hydrodynamic impacts
url https://doi.org/10.1002/vzj2.20233
work_keys_str_mv AT ssevincsengor colloidaltransportofheavymetalsinlowadvectivevelocityenvironmentalsystemsreactivetransportmodelonbiogeochemicalandhydrodynamicimpacts
AT kahramanunlu colloidaltransportofheavymetalsinlowadvectivevelocityenvironmentalsystemsreactivetransportmodelonbiogeochemicalandhydrodynamicimpacts