Accession Number : ADA559208


Title :   Influence of pH on the Transport of Silver Nanoparticles in Saturated Porous Media: Laboratory Experiments and Modeling


Descriptive Note : Master's thesis


Corporate Author : AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH GRADUATE SCHOOL OF ENGINEERING AND MANAGEMENT


Personal Author(s) : Flory, Jason R


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a559208.pdf


Report Date : Mar 2012


Pagination or Media Count : 55


Abstract : Given the ubiquity of silver nanoparticles (AgNPs), the largest and fastest growing category of nanomaterials, and their potential for toxic effects to both humans and the environment, it is important to understand their environmental fate and transport. The purpose of this study is to gain information on the transport properties of unmodified AgNP suspensions in a glass bead-packed column under saturated flow conditions at different solution pH levels. Commercial AgNPs were characterized using high resolution transmission spectroscopy (HRTEM), dynamic light scattering (DLS) and ultraviolet (UV) visible spectroscopy. Transport data were collected at different pH levels (4, 6.5 and 9) at fixed ionic strength. Capture of AgNPs increased as the pH of the solution increased from 4 to 6.5. Further increase in pH to 9 decreased the attachment of AgNPs to the glass beads. AgNP concentration versus time breakthrough data were simulated using an advection-dispersion model incorporating both irreversible and reversible attachment. In particular, a reversible attachment model is required to simulate breakthrough curve tailing at near neutral pH, when attachment is most significant.


Descriptors :   *NANOPARTICLES , *PH FACTOR , *SILVER , *TRANSPORT PROPERTIES , ATTACHMENT , IONIC STRENGTH , LABORATORY TESTS , NANOMATERIALS , POROUS MATERIALS , SIMULATION , SOLUTIONS(MIXTURES) , THESES , TOXICITY


Subject Categories : Toxicology
      Inorganic Chemistry
      Physical Chemistry


Distribution Statement : APPROVED FOR PUBLIC RELEASE