Electrobioremediation of an unsaturated soil contaminated with hydrocarbon after landfarming treatment

Abstract

The electro-bioremediation is a technique that is used for the remediation of hydrocarbon contaminated soils. The aim of this study is to explore the electrobioremediation of an unsaturated soil, contaminated with hydrocarbon waste generated by the oil industry activity in the area and previously remediated by landfarming, to in order to increase the removal of polyaromatic hydrocarbons. The sample was put in a three-compartment electro-bioremediation glass cell of 58 cm long, the lateral compartments containing the electrolyte; we used bridges of ammonium phosphate to connect the electrolyte with the soil sample in the central compartment. A potential difference of 0.5 V cm -1 was applied to the electrobioremediation cells for 60 days. A second cell was used for control and no current was applied to it. The monitoring was carried out by a counting cell and measuring of nalkanes and polyaromatic hydrocarbons using GC mass. The results showed that this technology has good potential to increase the biodegradation of n-alkane hydrocarbons and polyaromatic hydrocarbons such as phenanthrene, 1-3-metilphenanthrene, chrysene, 3-methylchrysene, 6-methylchrysene, benzo(b)fluoranthrene and benzo(ghi)pyrene which, without the application of direct current, were not biodegraded by microorganisms in the soil. The use of salt bridges maintained the pH between values that are compatible with the degrading bacterial community.

Enhanced ex-situ bioremediation of soil contaminated with petroleum refinery waste effluents by biostimulation through electrokinetics and inorganic fertilizer

“…Despite this observed loss, greater removal or degradation of TOC was observed in SEKRs exposed to direct electric current than in the SEKR without direct current application, which suggests that the application of electric current stimulates broader and more extensive removal or degradation of TOC. This is in agreement with the observations of Niqui-Arroyo, et al [33] for phenanthrene-contaminated soil, Li, et al [31] for crude oil contaminated soil, Acuǹa, et al [34] for hydrocarbon contaminated soil, respectively. The removal of TOCs in the SEKRs with 0.33, 0.67, and 1.0 V/cm was statistically significant (P = 0.05) in comparison to the removal of TOC in SEKR without voltage application.…”

“…Lee, et al [36] used electrokinetics to enhance transportation of nutrient phosphorus in the petroleum polluted soil. The use of phosphate salt as nutrient to enhance electro-bioremediation of hydrocarbon contaminated soil has been reported by Acuǹa, et al [34].…”

Electrobioremediation of Hydrocarbon Contaminated Soil from Patagonia Argentina

“…In similar conditions with saturated soil this effect was not observed [18,28,45]. The lack of moisture change in experiment I is thought to be because the acidic pH increased the soil zeta potential, rapidly causing electroosmotic flow into the acidified region to reduce or even reverse [46].…”

“…The electrokinetic reactor used in this study was similar to that used in previous electrokinetic research [28]. Electrokinetic experiments at constant potential were carried out using an experimental apparatus for the electrokinetic tests that consisted of three main parts: soil cells, electrode compartments and power supply.…”