Effect of rhamnolipid biosurfactant on transport and retention of iron oxide nanoparticles in water-saturated quartz sand
- 18 December 2020
- journal article
- research article
- Published by Royal Society of Chemistry (RSC) in Environmental Science: Nano
- Vol. 8 (1), 311-327
- https://doi.org/10.1039/d0en01033b
Abstract
Although prior studies have investigated the effects of solution constituents, including dissolved organic matter and synthetic polymers, on nanoparticle mobility in porous media, far less attention has been directed toward evaluating the impacts of biosurfactants secreted by microorganisms on the transport and retention behavior of nanomaterials. The objective of this study was to explore the influence of rhamnolipid, a biosurfactant associated with biofilms, on the transport and retention of iron oxide nanoparticles (IONPs) in a water-saturated quartz sand. Column experiments were conducted using aerobic medium (ionic strength = 50.4 mM) or 10 mM NaCl as background electrolyte at a pore velocity of 0.43 m per day and pH 6.8 ± 0.2. In aerobic medium columns, nearly all introduced nanoparticles were retained when IONPs were injected alone, whereas the presence of 10 mg L−1 or 50 mg L−1 rhamnolipid resulted in ∼25% and ∼50% breakthrough of the injected IONP mass, respectively. Moreover, preflushing media with 50 mg L−1 rhamnolipid further increased IONP mass breakthrough by ∼30%. Similar enhancement of nanoparticle mobility by 50 mg L−1 rhamnolipid was also measured in lower ionic strength (10 mM NaCl) columns. Mathematical models that incorporated nanoparticle filter ripening and biosurfactant competitive adsorption successfully reproduced experimental observations. Modeling results predicted an order-of-magnitude decrease in IONP filter ripening rate coefficient and a three-fold drop in average IONP retention capacity in the presence of rhamnolipid, consistent with a stabilizing effect and competition for surface sites. These findings demonstrate that rhamnolipid biosurfactant can potentially enhance nanomaterial stability and mobility in subsurface environments and that these effects should be considered when evaluating the impact of biological process on nanoparticle fate and transport in porous media.Keywords
Funding Information
- National Institute of Food and Agriculture (2018-67021-28319)
- National Science Foundation (CBET-170536)
This publication has 105 references indexed in Scilit:
- Sensitivity of the transport and retention of stabilized silver nanoparticles to physicochemical factorsWater Research, 2013
- Distinct Effects of Humic Acid on Transport and Retention of TiO2 Rutile Nanoparticles in Saturated Sand ColumnsEnvironmental Science & Technology, 2012
- Transport Behavior of Selected Nanoparticles with different Surface Coatings in Granular Porous Media coated with Pseudomonas aeruginosa BiofilmEnvironmental Science & Technology, 2011
- Modeling colloid transport and retention in saturated porous media under unfavorable attachment conditionsWater Resources Research, 2011
- Transport and Retention of TiO2 Rutile Nanoparticles in Saturated Porous Media under Low-Ionic-Strength Conditions: Measurements and MechanismsLangmuir, 2011
- Mixing Behavior of the Biosurfactant, Rhamnolipid, with a Conventional Anionic Surfactant, Sodium Dodecyl Benzene SulfonateLangmuir, 2010
- Physical factors affecting the transport and fate of colloids in saturated porous mediaWater Resources Research, 2002
- The ferrozine method revisited: Fe(II)/Fe(III) determination in natural watersApplied Geochemistry, 2000
- Colloid release and transport processes in natural and model porous mediaColloids and Surfaces A: Physicochemical and Engineering Aspects, 1996
- TRANSFORMATION OF BIOCHEMICALLY DEFICIENT STRAINS OF BACILLUS SUBTILIS BY DEOXYRIBONUCLEATEProceedings of the National Academy of Sciences of the United States of America, 1958