Electrokinetic remediation of gasoil contaminated soil enhanced by rhamnolipid

Abstract

Electrokinetic remediation (EKR) has been investigated as one of the best technologies in soil remediation but its applications for organic contaminants have been limited due to low solubility of organics in water and their non-ionic nature. The use of biosurfactants may increase the remediation efficiency by increasing the solubility of organics. The purpose of the introduction of complexing substances is to enhance the EKR process forming complexes and/or increasing the electro-osmotic flow. In this study, the removal of gasoil from a soil using electrokinetic method was investigated in the presence of Rhamnolipid at various concentrations. EKR experiments were undertaken on a gasoil contaminated soil (20,000 ppm). Graphite carbon electrodes were used to provide an electrical direct current (ddp 30-60 V). Results showed that increasing the dose of Rhamnolipid, the efficiency of gasoil removal increased up to 86.7%. Moreover, the lower concentration of the gasoil observed in the liquid phase at the higher concentration of the biosurfactant clearly indicated that the Rhamnolipid addition can enhance gasoil biodegradation

Effect of polarity-reversal on electrokinetic enhanced bioremediation of Pyrene contaminated soil

“…The pH jump is detrimental to microorganism and thus hampers the efficiency of bioremediation. To overcome the drawback, a series of methods were used to control the pH, such as injecting solution [11][12][13], fixing the cathode and approaching anodes [14,15], electrolyte circulation [16,17] and non-uniform electrokinetics [5,18]. Polarity reversal was proposed for neutralizing soil pH and stimulating bioremediation of organic contaminated soil [4,9,19].…”

Treatment and recovery of contaminated railway ballast

“…In the view of a future optimization of the washing conditions, this should be taken into account and a final washing with water is required before reuse or disposal of the stones, as generally required after chelant-assisted washing of contaminated soil and sediments [19,25].…”

Effect of Organic Matter on Hexavalent Chromium Reduction by Nano Zero Valent Iron in Soil

“…Simple aliphatic organics acids with one to three carboxylic acid groups such as acetic, citric, formic, fumaric, lactic, oxalic, malonic, valeric, succinic, tartaric and p-hydroxybenzoic acid occur frequently in soil and subsurface environments. Such compounds are released by organisms or are produced during the decomposition of larger biopolymers and can alter chemical processes in soils through complexation with metal ions in solution and ligand exchange reactions at soil surfaces [9]. They play a crucial role in chromate reduction by Fe 0 nanoparticles via adsorption and complexation with surface sites of Fe 0 and/or with the iron corrosion products.…”