Development of Natural Organic Matter as a Permeable Reactive Barrier Medium for Pipeline Leakage

Abstract

This paper presents the development of a new remediation technology of contaminated soil and groundwater using humic acid (HA) in permeable reactive barrier (PRB) for pipeline leakage. The objective of this study was to use humic acid that could be medium within a PRB to filter complex contaminated soil and groundwater containing chromium. Leakage of pollutants (such as hydrocarbon、gasoline、oil、wastewater、heavy metal et al) has a large economic and environmental impact. When a pipeline leak is large or undiscovered for a longer period of time, substantial volumes of gases and liquids can leak into the soil and groundwater, which can develop into dangerous situations involving costly remediation works. Traditional methods for remedying contaminated soil and groundwater from pipeline leakage, such as drilling and geochemical analysis, are destructive, time consuming and expensive. A PRB was determined to be the best option for remedying groundwater that has become contaminated with a wide range of organic contaminants (i.e., benzene, toluene, methylbenzene, xylene and polyaromatic hydrocarbons), heavy metals (i.e., lead and arsenic). PRB is installed in or down gradient from the flow path of a contaminant plume. The contaminants in the plume react with the media inside the barrier to either break the compound down into harmless products or immobilize contaminants by precipitation or sorption. It is made up of humic acid that reduce contaminants. With the development of industry and agriculture, environmental contamination has become more and more serious, especially heavy metal pollution, have been a major environmental issue, drawing much scientific and public attention. Chromium is identified as “priority pollutant” by the United States Environment Protection Agency (US EPA). the measurements show a significant increase of the adsorption of Cr (VI) because of the complexion reaction between HA and Cr (VI) occurred under acidic condition. It could be concluded that HA could be used effectively on remediation of Cr (VI)-contaminated soil and groundwater in a wide range of pH, with or without sunlight.