The use of non-uniform electrokinetics to enhance in situ bioremediation of phenol-contaminated soil

Luo, Qingzhi; Zhang, Xihui; Wang, Hui; Qian, Yi

doi:10.1016/j.jhazmat.2005.02.007

Cited by 95 publications

(62 citation statements)

References 18 publications

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“…Furthermore, these observations revealed that irrespective of the applied specific voltage, pH relatively increased with increased distance from anode (conversely, pH decreased with increase of distance from cathode). Similar observations have been reported [12,30,35].It was generally observed that the moisture content decreased with time at the different applied voltage and hence sterilized distilled water was added at intervals so as maintain the moisture content at 30%.…”

Section: Effect Of Nutrient On Electro Bioremediationsupporting

confidence: 86%

“…Seven spots, with distances of 1, 4, 7, 10, 13, 16 and 19 cm from the (initial) anode, were sampled on each line, as shown in Figure 1. In addition, soil pH was determined using a soil-to-water ratio of 1:2.5 and water content was determined using the methods described by Luo [30]. All the analysis was performed in triplicate, and the result was calculated as the average.…”

Section: Electrokinetic Experimental Proceduresmentioning

confidence: 99%

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

Agarry¹

2017

Nig. J. Tech.

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Ex situ bioremediation is an attractive and often cost-effective technology for the clean-up of organics-contaminated sites; however, it often requires extended treatment time under field conditions. Electrokinetic bioremediation is an emerging technology to remediate organic-contaminated soil. Thus, the objective of this study was to investigate the feasibility and effectiveness of using electrical biostimulation processes to enhance ex-situ bioremediation of soils contaminated with organic pollutants. The effect of different applied voltages (0.33 -1.0 V/cm) as well as the effect of inorganic (NPK) fertilizer on the electrokinetic bioremediation of soil was evaluated. A bench-scale uniform electrokinetic system was developed for this purpose and tested by using a sandy loam soil spiked with petroleum refinery waste effluent having total organic compound (TOC) as model organic pollutant. The results demonstrated that the application of a low direct current (voltage) could be an effective strategy to accelerate the movement and ex situ biodegradation or removal of TOC in the soil. At the application of 0.33, 0.67 and 1.0 V/cm voltage, electricity biostimulation correspondingly and averagely remove 65.7%, 70% and 73.3% of TOC from soil in only 15 days without nutrient (NPK fertilizer) application; while with nutrient application, electricity biostimulation correspondingly and averagely removed 71.8%, 77.4% and 81.6% of TOC from soil. Thus, bioremediation of soil contaminated with petroleum refinery waste effluents can be enhanced by electrokinetics and the rate of TOC biodegradation or removal relatively increased with increased specific voltage application. The electrokinetic bioremediation of soil can further be enhanced or accelerated with the addition of nutrient in the form of nitrogen, phosphorus and potassium (NPK). Small changes in soil pH and/or moisture were induced by the applied electric field.

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Section: Effect Of Nutrient On Electro Bioremediationsupporting

confidence: 86%

Section: Electrokinetic Experimental Proceduresmentioning

confidence: 99%

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

Agarry¹

2017

Nig. J. Tech.

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“…the indigenous HOC-degrading soil bacteria ). When DC is applied to living microbial cells, various responses, such as toxic electrode effects, metabolic stimulation due to enhanced substrate mass transfer (Pribyl et al 2001), sublethal injuries (Guillou et al 2003), irreversible dielectric cell membrane breakdown (Zimmermann et al 1974), or changes in the physicochemical surface properties (Luo et al 2005) can be observed depending on the applied current, treatment time, cell type and medium characteristics (Velizarov 1999). Earlier studies using soil have shown that the application of 20 mA cm -2 DC current stimulated the activity of sulphur-oxidising bacteria (Jackman et al 1999) or the biological denitrification of nitrate-contaminated groundwater (Hayes et al 1998) due to the production of H 2 and subsequent pH changes.…”

Section: Introductionmentioning

confidence: 99%

Effect of electrokinetic transport on the vulnerability of PAH-degrading bacteria in a model aquifer

Shi

Müller

Harms

et al. 2008

Environ Geochem Health

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There has been increasing interest in employing electro-bioremediation, a hybrid technology of bioremediation and electrokinetics, to overcome the low bioavailability of hydrophobic organic contaminants (HOC) by homogenizing sorption-retarded HOC and immobilised microorganisms. Present electro-remediation approaches mainly aim at macroscale pollutant extraction and tend to neglect possible impacts of direct current (DC) on the physiology of microorganisms. The effect of weak electric fields (X = 1 V cm(-1)) on the fitness of electrokinetically dispersed fluorene-degrading Sphingomonas sp. LB126 in bench-scale model aquifers was investigated by flow cytometry using propidium iodide (PI) as an indicator that distinguishes between PI-permeable (cells with porous membranes, i.e. dead or vulnerable) and PI-impermeable bacteria. After 15.5 h of DC treatment 56% of all cells recovered were dispersed at the centimetre scale relative to 29% in the absence of DC. There was no overall negative effect of the 15.5-h DC treatment on cell vulnerability, as 7.0% of the DC-treated bacteria exhibited PI-staining compared to 6.5% of the control population. Minor differences were observed in the subpopulation that had been mobilised by electroosmosis with an approximately twofold increase in the percentage of PI-stained cells relative to the control. Enhanced PI staining did not correlate with reduced culturability of the cells on rich-medium agar plates. Relative to the control, DC-treated cells mobilised by electroosmosis were threefold more culturable, confirming earlier data that that PI-cell membrane permeability does not always indicate reduced viability of oligotrophic environmental bacteria. Our findings suggest that electrokinetics is a valuable mechanism to transport viable and culturable polycyclic aromatic hydrocarbon (PAH)-degrading bacteria in soil or sediments.

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“…The conventional techniques include the use of an ion selective membrane such as cation-exchange membrane, which prevents the transport of the hydroxide ions from the cathode to the soil as shown in Figure 1 [57], continuous changing/removing of the solution in the electrode compartments [58], addition of chemical conditioning agents such as ethylenediaminetetraacetic (EDTA) [59] [60], acetic acid [55], and nitric acid [61]. Innovative techniques on the other hand include a stepwise moving anode [62] [63], polarity exchange [12] [64], circulation of an electrolyte (anolyte and catholyte) solution in the electrode compartments (see Figure 2) [35] [43] [65], and the two anodes technique (TAT) (see Figure 3) which has investigated the control of the advancement of the acid and the base fronts. The soil type (mostly buffer capacity) and the presence of anions which contribute to the buffer capacity (besides carbonates, hydrocarbonates and hydroxides): borates, phosphates, silicates and organic acids anions influence the pH changes and should be taken into account when choosing the right pH-regulation technique [63].…”

Section: Ph Gradientmentioning

confidence: 99%

“…The polarity exchange technique relies mainly on the preciseness of pH measurement during the treatment and the current intensity. The soil pH and water content of phenol-contaminated soil were controlled using the polarity reversal technique [12]. This technique can be suitable for EK bioremediation, however, continuous pH monitoring is required which is challenging and increases the overall cost of the process.…”

Section: Ph Gradientmentioning

confidence: 99%

A Review Article: Electrokinetic Bioremediation Current Knowledge and New Prospects

Hassan¹,

Mohamedelhassan²,

Yanful³

et al. 2016

AiM

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This study discusses factors affecting various processes involved in bioremediation coupled with electrokinetics. The study presents innovative solutions, and proposes new directions. Environmental conditions that have an influence on the characteristics, behavior, and metabolism of indigenous microorganisms are presented. The discussion focuses on overcoming the unfavorable conditions created by electrolysis reactions, prolongation the survival of the microbes at contaminated sites, increase of microbial enzyme secretion, improvement of the indigenous bacteria metabolic pathways, and exploration of metagenomics resources from soil biota. The challenge facing the implementation of conventional bioremediation techniques in precisely and effectively delivering nutrients to indigenous bacteria, particularly in soils with tortuous paths and low hydraulic conductivity is discussed. Current knowledge in application of enhanced biostimulation using electrokinetics is reviewed. The implementation of bioaugmentation in bioremediation coupled with electrokinetics to enhance the outcome of bioremediation is presented. Effects of phenomena associated with electrokinetics in the hybrid remediation approach are discussed.

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The use of non-uniform electrokinetics to enhance in situ bioremediation of phenol-contaminated soil

Cited by 95 publications

References 18 publications

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

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

Effect of electrokinetic transport on the vulnerability of PAH-degrading bacteria in a model aquifer

A Review Article: Electrokinetic Bioremediation Current Knowledge and New Prospects

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