Ex Situ Bioremediation of Contaminated Soils: An Overview of Conventional and Innovative Technologies

Abstract

Bioremediation as a sustainable alternative to chemical-physical processes is an attractive solution for soil decontamination and renewal of polluted sites. Depending on the site characteristics and target treatment requirements for the decontaminated soil, in situ or ex situ technologies are employed. Ex situ technologies are advantageous when a safe and effective intervention is required (i.e., in the presence of severe contamination of highly hazardous compounds). In this review, conventional and innovative ex situ technologies for soil bioremediation are presented. For each one the principle of operation and recent applications are reported. In addition, strategies to improve their efficiency are explored. Finally, the possibility of making these technologies more competitive by indicating research needs for their future development is highlighted.

On-site and in situ remediation technologies applicable to petroleum hydrocarbon contaminated sites in the Antarctic and Arctic

“…Ex situ remediation approaches can be advantageous in the presence of severe contamination of highly hazardous compounds (Tomei & Daugulis 2013). However, such approaches are expensive, logistically inefficient and may result in further damage to the natural environment.…”

“…Technology coupling is also advantageous and can increase the efficiency and spectrum of contaminated site management (Tomei & Daugulis 2013). Technology coupling is particularly favourable at sites co-contaminated with metals and petroleum hydrocarbons, where remediation of co-contaminated soil by the use of a single technology is challenged by the unique and occasionally conflicting chemistry, toxicity and remediation requirements of individual pollutants (Dong et al 2013).…”

Landfarming: A contested space for the management of waste from oil and gas extraction

“…While landfarming is a relatively low-cost process with low technology input, it does require available land and is not suitable for waste with high concentrations of contaminants (Ball et al, 2012;Maila and Cloete, 2004;NSW EPA, 2014;Tomei and Daugulis, 2013). Landfarms are exposed to prevailing climactic conditions, including seasonal changes in temperature, rainfall and wind-led erosion.…”

“…5 It involves the controlled spreading of waste onto the land surface and its incorporation into the soil. The aim is to allow the dilution and natural attenuation of any contaminants in the waste (Ball et al, 2012) and has been used in a range of geographic conditions around the world (Tomei and Daugulis, 2013).…”

Hydrocarbon pollution does not influence bacterial diversity as much as geographic location: a Korean case study

“…These sites are on various stages of bioremediation, and one of the first questions to be answered is to determine the mode of remediation, in situ or ex situ (Tomei and Daugulis 2012;McGenity 2014;Gillespie and Philp 2013). While in situ bioremediation is usually preferred considering its applicability and low cost, there are still questions over use of indigenous microorganisms or external consortium.…”