scholarly journals Coupled Electrokinetics-Adsorption Technique for Simultaneous Removal of Heavy Metals and Organics from Saline-Sodic Soil

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Salihu Lukman ◽  
Mohammed Hussain Essa ◽  
Nuhu Dalhat Mu'azu ◽  
Alaadin Bukhari
Keyword(s):  
Heavy Metals ◽  
Contaminated Soils ◽  
Contaminant Removal ◽  
In Situ Remediation ◽  
Sodic Soils ◽  
Sodic Soil ◽  
Mixed Contaminants ◽  
Removal Of Heavy Metals ◽  
Promising Solution

In situ remediation technologies for contaminated soils are faced with significant technical challenges when the contaminated soil has low permeability. Popular traditional technologies are rendered ineffective due to the difficulty encountered in accessing the contaminants as well as when employed in settings where the soil contains mixed contaminants such as petroleum hydrocarbons, heavy metals, and polar organics. In this study, an integrated in situ remediation technique that couples electrokinetics with adsorption, using locally produced granular activated carbon from date palm pits in the treatment zones that are installed directly to bracket the contaminated soils at bench-scale, is investigated. Natural saline-sodic soil, spiked with contaminant mixture (kerosene, phenol, Cr, Cd, Cu, Zn, Pb, and Hg), was used in this study to investigate the efficiency of contaminant removal. For the 21-day period of continuous electrokinetics-adsorption experimental run, efficiency for the removal of Zn, Pb, Cu, Cd, Cr, Hg, phenol, and kerosene was found to reach 26.8, 55.8, 41.0, 34.4, 75.9, 92.49, 100.0, and 49.8%, respectively. The results obtained suggest that integrating adsorption into electrokinetic technology is a promising solution for removal of contaminant mixture from saline-sodic soils.

Synergistic Effect of Rhamnolipid and Saponin Biosurfactants on Removal of Heavy Metals from Oil Contaminated Soils

2020 ◽  
Vol 57 (2) ◽  
pp. 109-114
Author(s):  
Amirhossein Dolatzadeh khiyavi ◽  
Reza Hajimohammadi ◽  
Hossein Amani ◽  
Hadi Soltani
Keyword(s):  
Heavy Metals ◽  
Synergistic Effect ◽  
Contaminated Soils ◽  
Removal Of Heavy Metals

scholarly journals Enhanced Electrokinetic Remediation for the Removal of Heavy Metals from Contaminated Soils

2021 ◽  
Vol 11 (4) ◽  
pp. 1799
Author(s):  
Claudio Cameselle ◽  
Susana Gouveia ◽  
Adrian Cabo
Keyword(s):  
Heavy Metals ◽  
Citric Acid ◽  
Organic Acids ◽  
Contaminated Soils ◽  
Electrokinetic Remediation ◽  
Deionized Water ◽  
Soil Specimen ◽  
Removal Of Heavy Metals ◽  
Ph Conditions ◽  
Neutral Metal

The electrokinetic remediation of an agricultural soil contaminated with heavy metals was studied using organic acids as facilitating agents. The unenhanced electrokinetic treatment using deionized water as processing fluid did not show any significant mobilization and removal of heavy metals due to the low solubilization of metals and precipitation at high pH conditions close to the cathode. EDTA and citric acid 0.1 M were used as facilitating agents to favor the dissolution and transportation of metals. The organic acids were added to the catholyte and penetrated into the soil specimen by electromigration. EDTA formed negatively charged complexes. Citric acid formed neutral metal complexes in the soil pH conditions (pH = 2–4). Citric acid was much more effective in the dissolution and transportation out of the soil specimen of complexed metals. In order to enhance the removal of metals, the concentration of citric acid was increased up to 0.5 M, resulting in the removal of 78.7% of Cd, 78.6% of Co, 72.5% of Cu, 73.3% of Zn, 11.8% of Cr and 9.8% of Pb.

In situ multiphase fluidization ("upflow washing") for the remediation of hydrocarbon contaminated sands

1998 ◽  
Vol 35 (6) ◽  
pp. 938-960 ◽  
Author(s):  
Robert K Niven ◽  
Nasser Khalili
Keyword(s):  
Theoretical Analysis ◽  
Contaminated Soils ◽  
Fixed Bed ◽  
Fine Sand ◽  
In Situ Remediation ◽  
Pump And Treat ◽  
Wide Range ◽  
Phase Liquid ◽  
Regime Map

A new in situ remediation method is described, "upflow washing," in which contaminants are flushed to the surface within an in situ fluidized zone produced by a jet inserted into a granular formation. The suitability of the method for LNAPL (light non-aqueous phase liquid) remediation is examined by experiments on diesel-contaminated soils within column and tank settings. The experiments indicate significant reductions in diesel levels (96-99.9%) may be achieved by fluidization with water and gas (gas-liquid upflow washing, GLUW) for a wide range of initial diesel concentrations (10 000 to 150 000 mg/kg) and for soil fines contents of 0 to at least 10%. Final diesel levels of <1000 mg/kg in a uniform fine sand and <200 mg/kg in clayey sands can be achieved. The efficiency is much higher than that of fixed bed flushing (simulated pump-and-treat), as the method overcomes the trapping of NAPL ganglia. Fludization with water alone (liquid upflow washing, LUW) is less effective than fixed bed flushing in the uniform sand, but approaches that of GLUW in clayey and silty sands. The results are explained by theoretical analysis of the removability of isolated NAPL droplets and mixed solid - NAPL particles from a fluidized bed due to buoyancy and elutriation, which may be represented using a "removability regime map" for the diesel-water-sand system.Key words: fluidization, in situ, remediation, NAPL, diesel.

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