DOE PAGES title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Establishing Vadose Zone Slow‐Release Carbon Sources for Enhanced Bioremediation Using Silica Suspension

Abstract

Core Ideas Nutrient‐laden silica suspension increases viscosity over time and gels at the end. Aqueous colloidal silica suspension can be readily injected into the subsurface. Silica gelation enables setting up slow‐release nutrient sources in the vadose zone. Gelled silica suspensions act as long‐term nutrients for enhanced bioremediation. Delivery of C sources (nutrients) to the vadose zone and establishing a slow‐release C source in this unsaturated zone are essential for promoting long‐term, enhanced contaminant bioremediation at sites with deep vadose zones, such as the Hanford Site in the southeast of the state of Washington. Conventional solution‐based injection and infiltration approaches face challenges in achieving delivery goals. Aqueous colloidal silica suspension has characteristics that can potentially be used for nutrient delivery and slow‐release source setup. This research was conducted to (i) demonstrate delayed gelation of colloidal silica suspensions with the presence of nutrients; (ii) prove that gelation takes place in sediment and the gel slowly releases nutrients; and (iii) show that silica suspensions are injectable for vadose zone emplacement. Results demonstrated that nutrient‐laden colloidal silica suspensions have low initial viscosity and then increase in viscosity with time until reaching gelation, allowing for a slow release of nutrients into the environment. Higher saltmore » and silica concentrations increased the rate of viscosity climbing and the rate of gelation, whereas higher silica concentrations resulted in stronger gels. Nutrients were slowly released from gels in both batch and column experimental settings. The rheological and injection behavior of the silica suspensions revealed the injectability of these fluids. This study demonstrated that colloidal silica suspension could be used as a carrier to distribute nutrients to the vadose zone and to establish slow‐release nutrient sources.« less

Authors:
 [1];  [1];  [2]
  1. Energy and Environment Directorate, Pacific Northwest National Lab. Richland WA 99352
  2. Institute of Process Engineering Chinese Academy of Sciences Beijing 100190 China
Publication Date:
Research Org.:
Pacific Northwest National Laboratory (PNNL), Richland, WA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1787376
Alternate Identifier(s):
OSTI ID: 1511145; OSTI ID: 1787381
Report Number(s):
PNNL-SA-129486
Journal ID: ISSN 1539-1663
Grant/Contract Number:  
AC05-76RL01830
Resource Type:
Published Article
Journal Name:
Vadose Zone Journal
Additional Journal Information:
Journal Name: Vadose Zone Journal Journal Volume: 17 Journal Issue: 1; Journal ID: ISSN 1539-1663
Publisher:
Wiley Blackwell (John Wiley & Sons)
Country of Publication:
United States
Language:
English
Subject:
54 ENVIRONMENTAL SCIENCES

Citation Formats

Zhong, Lirong, Lee, Brady, and Yang, Shuo. Establishing Vadose Zone Slow‐Release Carbon Sources for Enhanced Bioremediation Using Silica Suspension. United States: N. p., 2018. Web. doi:10.2136/vzj2017.09.0175.
Zhong, Lirong, Lee, Brady, & Yang, Shuo. Establishing Vadose Zone Slow‐Release Carbon Sources for Enhanced Bioremediation Using Silica Suspension. United States. https://doi.org/10.2136/vzj2017.09.0175
Zhong, Lirong, Lee, Brady, and Yang, Shuo. Thu . "Establishing Vadose Zone Slow‐Release Carbon Sources for Enhanced Bioremediation Using Silica Suspension". United States. https://doi.org/10.2136/vzj2017.09.0175.
@article{osti_1787376,
title = {Establishing Vadose Zone Slow‐Release Carbon Sources for Enhanced Bioremediation Using Silica Suspension},
author = {Zhong, Lirong and Lee, Brady and Yang, Shuo},
abstractNote = {Core Ideas Nutrient‐laden silica suspension increases viscosity over time and gels at the end. Aqueous colloidal silica suspension can be readily injected into the subsurface. Silica gelation enables setting up slow‐release nutrient sources in the vadose zone. Gelled silica suspensions act as long‐term nutrients for enhanced bioremediation. Delivery of C sources (nutrients) to the vadose zone and establishing a slow‐release C source in this unsaturated zone are essential for promoting long‐term, enhanced contaminant bioremediation at sites with deep vadose zones, such as the Hanford Site in the southeast of the state of Washington. Conventional solution‐based injection and infiltration approaches face challenges in achieving delivery goals. Aqueous colloidal silica suspension has characteristics that can potentially be used for nutrient delivery and slow‐release source setup. This research was conducted to (i) demonstrate delayed gelation of colloidal silica suspensions with the presence of nutrients; (ii) prove that gelation takes place in sediment and the gel slowly releases nutrients; and (iii) show that silica suspensions are injectable for vadose zone emplacement. Results demonstrated that nutrient‐laden colloidal silica suspensions have low initial viscosity and then increase in viscosity with time until reaching gelation, allowing for a slow release of nutrients into the environment. Higher salt and silica concentrations increased the rate of viscosity climbing and the rate of gelation, whereas higher silica concentrations resulted in stronger gels. Nutrients were slowly released from gels in both batch and column experimental settings. The rheological and injection behavior of the silica suspensions revealed the injectability of these fluids. This study demonstrated that colloidal silica suspension could be used as a carrier to distribute nutrients to the vadose zone and to establish slow‐release nutrient sources.},
doi = {10.2136/vzj2017.09.0175},
journal = {Vadose Zone Journal},
number = 1,
volume = 17,
place = {United States},
year = {Thu Apr 12 00:00:00 EDT 2018},
month = {Thu Apr 12 00:00:00 EDT 2018}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record
https://doi.org/10.2136/vzj2017.09.0175

Citation Metrics:
Cited by: 3 works
Citation information provided by
Web of Science

Save / Share:

Works referenced in this record:

Hanford Site Vadose Zone Studies: An Overview
journal, January 2007

  • Gee, G. W.; Oostrom, M.; Freshley, M. D.
  • Vadose Zone Journal, Vol. 6, Issue 4
  • DOI: 10.2136/vzj2006.0179

Characterization of Miller-Similar Silica Sands for Laboratory Hydrologic Studies
journal, January 1996


Rheological Properties of Aqueous Colloidal Silica Suspensions Related to Amendment Delivery for Subsurface Remediation
journal, February 2018

  • Yang, Shuo; Zhong, Lirong; Li, Guanghe
  • Environmental Engineering Science, Vol. 35, Issue 2
  • DOI: 10.1089/ees.2017.0040

Enhanced remedial amendment delivery through fluid viscosity modifications: Experiments and numerical simulations
journal, October 2008


Characterization of silica–water nanofluids dispersed with an ultrasound probe: A study of their physical properties and stability
journal, July 2012


Temperature and pressure effects on stability and gelation properties of silica suspensions
journal, March 2011

  • Amiri, Asal; Øye, Gisle; Sjöblom, Johan
  • Colloids and Surfaces A: Physicochemical and Engineering Aspects, Vol. 378, Issue 1-3
  • DOI: 10.1016/j.colsurfa.2011.01.048

Shear thinning behavior of aqueous alumina nanoparticle suspensions with saccharides
journal, March 2014


Influence of pH, high salinity and particle concentration on stability and rheological properties of aqueous suspensions of fumed silica
journal, October 2009

  • Amiri, Asal; Øye, Gisle; Sjöblom, Johan
  • Colloids and Surfaces A: Physicochemical and Engineering Aspects, Vol. 349, Issue 1-3
  • DOI: 10.1016/j.colsurfa.2009.07.050

Injectable silica–permanganate gel as a slow-release MnO 4 source for groundwater remediation: rheological properties and release dynamics
journal, January 2016

  • Yang, S.; Oostrom, M.; Truex, M. J.
  • Environmental Science: Processes & Impacts, Vol. 18, Issue 2
  • DOI: 10.1039/C5EM00559K

Permanganate gel (PG) for groundwater remediation: Compatibility, gelation, and release characteristics
journal, February 2014


Coagulation of Colloidal Silica by Alkaline Cations: Surface Dehydration or Interparticle Bridging?
journal, October 1997