Inhibited transport of graphene oxide nanoparticles in granular quartz sand coated with Bacillus subtilis and Pseudomonas putida biofilms

Jian Zhou He, Deng Jun Wang, Huan Fang, Qing Long Fu, Dong Mei Zhou

Research output: Contribution to journalArticlepeer-review

34 Scopus citations

Abstract

Increasing production and use of graphene oxide nanoparticles (GONPs) boost their wide dissemination in the subsurface environments where biofilms occur ubiquitously, representative of the physical and chemical heterogeneities. This study aimed at investigating the influence of Gram-positive Bacillus subtilis (BS) and Gram-negative Pseudomonas putida (PP) biofilms on the transport of GONPs under different ionic strengths (0.1, 0.5, and 1.0 mM CaCl2) at neutral pH 7.2 in water-saturated porous media. Particularly, the X-ray micro-computed tomography was used to quantitatively characterize the pore structures of sand columns in the presence and absence of biofilms. Our results indicated that the presence of biofilms reduced the porosity and narrowed down the pore sizes of packed columns. Transport experiments in biofilm-coated sand showed that biofilms, irrespective of bacterial species, significantly inhibited the mobility of GONPs compared to that in cleaned sand. This could be due to the Ca2+ complexation, increased surface roughness and charge heterogeneities of collectors, and particularly enhanced physical straining caused by biofilms. The two-site kinetic retention model-fitted value of maximum solid-phase concentration (Smax2) for GONPs was higher for biofilm-coated sand than for cleaned sand, demonstrating that biofilms act as favorable sites for GONPs retention. Our findings presented herein are important to deepen our current understanding on the nature of particle-collector interactions.

Original languageEnglish
Pages (from-to)1-8
Number of pages8
JournalChemosphere
Volume169
DOIs
StatePublished - Feb 1 2017
Externally publishedYes

Scopus Subject Areas

  • Environmental Engineering
  • Environmental Chemistry
  • General Chemistry
  • Pollution
  • Public Health, Environmental and Occupational Health
  • Health, Toxicology and Mutagenesis

Keywords

  • Biofilm
  • Computed tomography
  • Graphene oxide nanoparticles
  • Modeling
  • Porous media
  • Transport

Fingerprint

Dive into the research topics of 'Inhibited transport of graphene oxide nanoparticles in granular quartz sand coated with Bacillus subtilis and Pseudomonas putida biofilms'. Together they form a unique fingerprint.

Cite this