Graphene oxide-facilitated transport of Pb2+ and Cd2+ in saturated porous media

Yanji Jiang; Xiongxiong Zhang; Xianqiang Yin; Huimin Sun; Nong Wang

doi:10.1016/j.scitotenv.2018.03.036

Graphene oxide-facilitated transport of Pb²⁺ and Cd²⁺ in saturated porous media

Sci Total Environ. 2018 Aug 1:631-632:369-376. doi: 10.1016/j.scitotenv.2018.03.036. Epub 2018 Mar 16.

Authors

Yanji Jiang¹, Xiongxiong Zhang¹, Xianqiang Yin², Huimin Sun³, Nong Wang⁴

Affiliations

¹ College of Natural Resources and Environment, Northwest A&F University, Yangling 712100, China.
² College of Natural Resources and Environment, Northwest A&F University, Yangling 712100, China; Key Laboratory of Plant Nutrition and the Agri-environment in Northwest China, Ministry of Agriculture, Yangling 712100, China. Electronic address: xqyin@nwsuaf.edu.cn.
³ College of Natural Resources and Environment, Northwest A&F University, Yangling 712100, China; Key Laboratory of Plant Nutrition and the Agri-environment in Northwest China, Ministry of Agriculture, Yangling 712100, China.
⁴ Agro-Environmental Protection Institute, Ministry of Agriculture of the People's Republic of China, Tianjin 300191, China.

PMID: 29525715
DOI: 10.1016/j.scitotenv.2018.03.036

Abstract

This paper provides an overview of the effect of graphene oxide (GO) on sorption, transport, and remobilization of Pb²⁺ and Cd²⁺ ions in saturated porous media. The affinity of GO to Pb²⁺ and Cd²⁺ ions was investigated via kinetic and isothermal sorption experiments. Laboratory packed-column experiments were also conducted to investigate the cotransport of Pb²⁺ and Cd²⁺ ions with GO across a quartz sand matrix. In addition, the Pb²⁺- and Cd²⁺-preequilibrated sand column was sequentially flushed with GO to test its remobilization effect on these ions. GO exhibited a high affinity toward both Pb²⁺ and Cd²⁺ ions with maximum sorption capacities of 1428.57 and 911.43mgg^-1, respectively. On the other hand, while GO improved the transport ability of Pb²⁺ and Cd²⁺, both ions reduced the mobility of GO in saturated porous media. Data from the elution experiment revealed that the high affinity of GO toward the metal ions led to the remobilization of the presorbed Pb²⁺ and Cd²⁺ ions onto the quartz sand surfaces and their concurrent migration across the sand column. XDLVO (Extended Derjaguin-Landau-Verwey-Overbeek) calculations were employed to interpret the GO transport behavior in the column wells. The cotransport of Pb²⁺ and Cd²⁺ ions with GO in the saturated quartz sand was successfully simulated by the advection-dispersion-reaction equation. Findings from this study provide an insight on the potential implications of remobilization and spread of pollutants by nanomaterials existing in vulnerable ecosystems.

Keywords: Cd(2+); Graphene oxide; Pb(2+); Sand column; Transport; XDLVO theory.