Science Inventory

Influence Of pH On The Transport Of Nanoscale Zinc Oxide In Saturated Porous Media

Citation:

Kanel, S. R. AND S. R. AL-ABED. Influence Of pH On The Transport Of Nanoscale Zinc Oxide In Saturated Porous Media. M.C. Roco (ed.), Journal of Nanoparticle Research. Springer SBM, New York, NY, 13(9):4035-4047, (2011).

Impact/Purpose:

To determine the influence of pH on the transport properties of pristine nZnO and carboxymethyl cellulose (CMC) stabilized nZnO (CMC-nZnO) suspension in silica sand packed column under saturated flow conditions.

Description:

Widespread use of nanoscale zinc oxide (nZnO) in various fields causes subsurface environment contamination. Even though the transport of dissolved zinc ions in subsurface environments such as soils and sediments has been widely studied, the transport mechanism of nZnO in such environments is poorly understood. In addition, nZnO is often combined with stabilizers or dispersing agents to prevent its aggregation in products. The purpose of this study to is determine the influence of pH on the transport properties of pristine nZnO and carboxymethyl cellulose (CMC) stabilized nZnO (CMC-nZnO) suspensions in silica sand packed column under saturated flow conditions. Transport data were collected at different pHs (pHs: 3, 7, 9 and 11) under 1 mL/min flow rate conditions in a 1.1 cm diameter column. It is found that the transport trends of pristin nZnO and CMC-nZnO were different. For pristine nZnO, mobility of total Zn reached a minimum around its point of zero charge (pH 8.9). Whereas in the case of CMC-nZnO, the mobility of total Zn decreased as the pH of the solution pH increased from 3 to 11. ZnO and Zn ion mixture were separated using diafiltration membrane. it showed that most of the nZnO and CMC-nZnO exists as Zn ion at pH 3 before and after eluting from the sand packed column whereas at pH 11, they exist as particles. This study shows the strong influence of pH and stabilizing agents on nZnO transport. These factors should be considered during subsurface transport of nZnO.

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Record Details:

Record Type: DOCUMENT (JOURNAL/PEER REVIEWED JOURNAL)
Product Published Date: 09/01/2011
Record Last Revised: 08/25/2011
OMB Category: Other
Record ID: 234377

Organization:

U.S. ENVIRONMENTAL PROTECTION AGENCY

OFFICE OF RESEARCH AND DEVELOPMENT

NATIONAL RISK MANAGEMENT RESEARCH LABORATORY

LAND REMEDIATION AND POLLUTION CONTROL DIVISION

WASTE MANAGEMENT BRANCH