Nonlinear Sorption of Organic Contaminant during Two-Dimensional Transport in Saturated Sand

Sang-Gil Lee,Jae-Woo Choi,Soonjae Lee

doi:10.3390/w13111557

Sang-Gil Lee, Jae-Woo Choi + Show 1 more

Open Access

https://doi.org/10.3390/w13111557

Copy DOI

Abstract

Multi-dimensional transport studies are necessary in order to better explain the fate of contaminants in groundwater. In this study, a two-dimensional transport experiment with organic contaminants in saturated sand was conducted to investigate the migration of the organic contaminant plume in multi-dimensional flow conditions. The transport test was conducted using toluene as a model organic contaminant in a saturated sand box under steady flow conditions. The initial plume was generated via injection at a point source. After 24 h, the plume distribution was delineated by interpolating toluene concentrations in the porewater samples. The mass centers of the toluene and the conservative tracer were almost coincident, but the size of the toluene plume was significantly reduced in longitudinal as well as transversal directions. The appropriateness of several types of sorption models were compared to describe the toluene sorption in two-dimensional transport system using numerical modeling. Among the sorption models, the Langmuir model was found to be the most appropriate to describe the sorption of toluene during two-dimensional transport. The results showed that two-dimensional experiments are better than one-dimensional column experiments in identifying the adsorption characteristics that occur during transport in saturated aquifers.

Highlights

Transport experiment, toluene plume showedsaturated a decrease in mass, as well as plume
The shape of ment, the toluene plume showed a decrease in mass, as well as plume size
The results of this study suggest a methodology for evaluating the fate and transport characteristics of organic pollutants in aquifers

Summary

Introduction

Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations. The leakage of petroleum oil from facilities designed for transport and storage is one of the major sources of groundwater contamination. Leaked oil penetrates into the underground environment and forms a non-aqueous liquid (NAPL) pool above or below the aquifer. Various contaminants are continuously supplied into the groundwater through the dissolution of organic compounds from the NAPL pool. The presence of organic contaminants in the groundwater could pose a serious hazard to public health and the environment. One of the most common hydrocarbon contaminants in soil and groundwater is BTEX (benzene, toluene, ethylbenzene, xylene) [1]. BTEX compounds are more toxic than liquid alkanes and are well-known toxicants to a wide range of biota [2]

Objectives

Methods

Conclusion