Transport and retention behavior of carbonaceous colloids in natural aqueous medium: Impact of water chemistry
Document Type
Article
Publication Date
1-1-2019
Abstract
Carbon based materials are emerging as a sustainable alternative to their metal-oxide counterparts. However, their transport behavior under natural aqueous environment is poorly understood. This study investigated the transport and retention profiles of carbon nanoparticles (CNPs) and graphene oxide quantum dots (GOQDs) through column experiments in saturated porous media. CNPs and GOQDs (30 mg/L) were dispersed in natural river water (RW) and passed through the column at a flow rate of 1 mL/min, which mimicking the natural water flow rate. After every 10 min, the column effluents were collected and the mass recovery and retention profiles were monitored. Results indicated that the transport of both carbonaceous colloids was predominantly controlled by surface potential and ionic composition of natural water. The CNPs with its high surface potential (−40 mV) exhibited more column transport and was less susceptible to solution pH (5.6–6.8) variation as compared to GOQDs (−24 mV). The results showed that, monovalent salt (NaCl) was one of the dominating factors for the retention and transport of carbonaceous colloids compared to divalent salt (CaCl2). Furthermore, the presence of natural organic matter (NOM) increased the transport of both carbonaceous colloids and thereby decreases the tendency for column retention.
Keywords
Carbon nanoparticles, Graphene oxide quantum dots, Transport, Retention profile, Natural organic matter, Agglomeration
Divisions
CHEMISTRY,GEOLOGY
Funders
University of Malaya HIR grant-UM C/625/1/HIR/MOHE/SC/04
Publication Title
Chemosphere
Volume
217
Publisher
Elsevier