Enhancement of Bioremediation and Phytoremediation Using Electrokinetics

Abstract

This chapter discusses the use of bioremediation and phytoremediation coupled with electrokinetics and presents the elements contributing to the success of the remediation process. A deep discussion and an overview of the current advancement in the biotechnologies are outlined in details. Innovative solutions for challenges facing the field application of the new technology are presented and new directions are proposed. A careful review for contaminated site conditions including pH, temperature, and other factors influencing the behavior of microbial community are presented. Great deal of discussion is around overcoming the adverse effect of electrolysis reactions, which is a by-product of electrokinetics. The discussion includes prolonging the survival of the indigenous bacteria, increase of microbial enzyme secretion, improvement of the indigenous bacteria metabolism, and exploration of metagenomics resources from soil biota. The challenges facing the field application of bioremediation and phytoremediation including the delivery of the electron donors and/or acceptors and nutrients to microorganisms involved in the biodegradation, particularly in clay soils, which has very low hydraulic conductivity, is discussed. The use of electrokinetics in biostimulation application to enhanced degradation of organic pollutant is reviewed. The implementation of bioaugmentation in bioremediation coupled with electrokinetics to enhance the outcome of bioremediation is presented.

Towards the application of electrokinetic remediation for nuclear site decommissioning

“…91 Important considerations for successful site-scale implementation of EKR-Bio for organic contaminants include prolonging the lifetime of indigenous microbiota, increasing metabolic rates and ensuring that metabolic pathways are not disrupted by the application of, or chemical by-products resulting from, the electrokinetic apparatus. 125 In particular, combining EKR-Bio reactors on the laboratory scale with solar (PV) cells was shown by Hassan et al to operate effectively in the mycobacterium-based remediation of artificially contaminated kaolinite mixtures (2 mg of phenanthrene per gram of dry soil). One month of EKR in plastic cells (LWH 35x12x10 cm) with variable voltage resulted in removal of up to 50% of pre-experiment phenanthrene levels.…”

Integrating Electrokinetic and Bioremediation Process for Treating Oil Contaminated Low Permeability Soil

“…In the EK-Bio and EKSF-Bio tests, the water in both electrolyte chambers is significantly reduced in the anode chamber. The process of electrolysis of water at the anode (2H 2 O → 4e -+ 4H + + O 2 ) and in the cathode (2H 2 O + 2e -→ 2OH -+ H 2 ) and electroosmosis in the electrolyte chamber causes water volume reduction [4]. In contrast to PR-EKBio, in this test the water in both electrolyte chambers tends to be stable and does not disappear too much during electrokinetic process.…”

“…In contrast to PR-EKBio, in this test the water in both electrolyte chambers tends to be stable and does not disappear too much during electrokinetic process. This phenomena occurs because most of the electrolyzed ions re-form water (neutralization) when the polarity reversal occurs [4], [9]. The distilled water may be replaced with mineral salt as both buffers and surfactants.…”

“…Therefore, bioremediation then used as a alternative technology that attract great attention from practitioner because it can eliminate pollutants easily through biodegradation process at low invesment cost. Nevertheless, the process of bioremediation requires long operational time so that there is a need for finding a right strategy to improve the process efficiency [4].…”

Comprehensive study of electrokinetic-assisted phytoextraction of metals from mine tailings by applying direct and alternate current

“…Some sustainable technologies have been implemented as a mitigation measure to reduce the negative impact of these pollutants. Phytoremediation is currently considered an economical and environmentally friendly option for the treatment of soils contaminated with metals [4]. Metals are removed from soil or other solid matrices through the absorption and accumulation in plant tissues, ideally in the aerial ones; this process is called phytoextraction.…”