Combined effect of physicochemical factors on the retention and transport of g-C3N4 in porous media

Shunan Dong; Wangwei Cai; Liting Sheng; Weimu Wang; Hui Liu; Jihong Xia

doi:10.1016/j.chemosphere.2020.127100

Combined effect of physicochemical factors on the retention and transport of g-C₃N₄ in porous media

Chemosphere. 2020 Oct:256:127100. doi: 10.1016/j.chemosphere.2020.127100. Epub 2020 May 20.

Authors

Shunan Dong¹, Wangwei Cai², Liting Sheng², Weimu Wang², Hui Liu², Jihong Xia³

Affiliations

¹ College of Agricultural Science and Engineering, Hohai University, Nanjing, 210098, China. Electronic address: dsn@hhu.edu.cn.
² College of Agricultural Science and Engineering, Hohai University, Nanjing, 210098, China.
³ College of Agricultural Science and Engineering, Hohai University, Nanjing, 210098, China. Electronic address: syjhxia@hhu.edu.cn.

PMID: 32460159
DOI: 10.1016/j.chemosphere.2020.127100

Abstract

The environmental behaviors of graphitic carbon nitride (g-C₃N₄) have drawn increasing attention in recent. Understanding the fate and transport of g-C₃N₄ in porous media is necessary for evaluating its environmental risks. Column experiments were used in this study to investigate the combined effect of ionic strength (IS) and other common physicochemical factors (i.e. sand grain size, solution pH, and humic acid concentration) on g-C₃N₄ transport. The one-site kinetic models were applied to simulate the retention and transport of g-C₃N₄ in porous media, which fitted the breakthrough curves very well. Experimental and model results showed that g-C₃N₄ had a weak mobility with the transport mass recovery (TMR) less than 39.6% at pH 6.0 in absence of humic acid (HA). The mobility of g-C₃N₄ was inhibited with decreasing sand grain size, and the inhibited efficiency was enhanced with IS. However, g-C₃N₄ transport was significantly enhanced with increasing pH and HA concentration, and the enhanced efficiency was more obviously at high IS. The maximum TMR (78.3%) of g-C₃N₄ was observed with the presence of 5 mg L^-1 HA. These results indicated that physicochemical factors played an important and combined role in controlling g-C₃N₄ transport in porous media, which would lead to the more complex evaluation on the environmental behaviors of g-C₃N₄.

Keywords: Combined effect; Physicochemical factors; Porous media; Transport; g-C(3)N(4).

MeSH terms

Graphite / chemistry*
Humic Substances / analysis
Kinetics
Models, Chemical*
Nitrogen Compounds / chemistry*
Osmolar Concentration
Porosity

Substances

Humic Substances
Nitrogen Compounds
graphitic carbon nitride
Graphite