Humic acids enhanced removal of aromatic hydrocarbons from contaminated aquifers: Developing a sustainable technology

Contamination by gasoline and diesel fuels is a threat to groundwater resou rces. Polynuclear aromatic hydrocarbons (PAHs) which can represent up to 60 % of volume in diesel fuels are of particular concern because many of them are carcinogenic and they are persistent, especially in oxygen-limited envi ronment. Despite the development of alternative approaches, pump and treat continues to be the leading technology for the remediation of groundwater c ontaminated by gasoline and diesel fuels. The efficiency of this technology is however limited by the low solubility of the aromatic hydrocarbons. The objective of this study was to investigate the influence of humic acids on the removal of aromatic hydrocarbons from petroleum products in groundwate r aquifers and to evaluate the potential use of humic acids, as a cost effe ctive additive, in groundwater and soil remediation. In order to prove the feasibility of using humic acid in the field, a pilot scale experiment was conducted in a model aquifer with a very dense monitoring network, providin g controlled conditions only possible in a semi-artificial system. In addit ion, different sources of humic acids were compared with surfactants for th eir ability to bind PAHs.