To improve the performance of focusing phenomenon related to energy consumption and removal efficiency in electrokinetic remediation of Cr-contaminated soil

2021 ◽  
pp. 118882
Author(s):  
Junnian Wu ◽  
Bo Wei ◽  
Ziwei Lv ◽  
Yupeng Fu
Keyword(s):  
Energy Consumption ◽  
Removal Efficiency ◽  
Contaminated Soil ◽  
Electrokinetic Remediation

Enhanced Electrokinetic Remediation of Cadmium (Cd)-Contaminated Soil With Interval Power breaking

2021 ◽  
Author(s):  
Zongping Cai ◽  
Yan Sun ◽  
Yanghong Deng ◽  
Xiaojie Zheng ◽  
Shuiyu Sun ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
Power Supply ◽  
Contaminated Soil ◽  
Laboratory Experiments ◽  
Electrokinetic Remediation ◽  
Charged Species ◽  
Continuous Power ◽  
Cd Removal ◽  
Cd Species ◽  
Soil Cd

Abstract This study compared electrokinetic (EK) remediation with and without interval power breaking in the removal of total and plant available cadmium (Cd) in the soil. Two laboratory experiments, i.e. EK remediation with interval power breaking (24-12 h power-on-off cycles) and conventional EK remediation (continuous power supply) with the same accumulated time (192 h) of power supply were conducted to remove soil Cd. After the EK remediation by interval power breaking, the total Cd removal efficiency in the soil rose to 38%, in comparison to 28% by the conventional EK remediation. As for the plant available Cd, the removal efficiency was enhanced from 52% to 63%. Additionally, the electric current during the EK remediation and electric conductivity after the EK remediation were higher in the soil treated by interval power breaking, which indicated an enhanced desorption and/or migration of charged species. It further meant that the higher removal efficiency of soil Cd by interval power breaking could be related to the enhanced desorption and/or migration of Cd species. This study indicated that both conventional EK remediation and EK remediation with interval power breaking were effective methods to remove soil Cd but EK remediation with interval power breaking was more efficient.

Response Surface Method Analysis on Electro-Enhanced Technique for Remediation of Cadmium Contaminated Soil

2020 ◽  
Vol 980 ◽  
pp. 502-511
Author(s):  
Yu Shan Wan ◽  
Ju An Zhai ◽  
An Wei Wang
Keyword(s):  
Energy Consumption ◽  
Field Strength ◽  
Electric Field ◽  
Electric Field Strength ◽  
Water Content ◽  
Contaminated Soil ◽  
Removal Rate ◽  
Electrokinetic Remediation ◽  
Surface Method ◽  
Remediation Time

In view of the problems of long remediation time, high energy consumption and low remediation efficiency in electrokinetic remediation of heavy metal contaminated soil, Cd was used to simulate heavy metals in contaminated soil, and response surface method (RSM) was used to optimize the factors influencing electrokinetic remediation. Central Composite (CCD) experimental design method was taken to study the effects of electric field strength, remediation time and water content on removal rate of Cd in soil. Also, polynomial regression mathematical model and optimal reaction conditions were provided for Cd pollution in electrokinetic soil remediation. The simulated equation F was 15.67, the correlation coefficient was 0.9338, and the adjustment correlation coefficient was 0.9042, indicating good regression and strong significance of the equation. The model results showed that, for the optimal experimental conditions, electric field strength was 2.25V·cm-1, the remediation time was 120.79h, and the water content was 17.06%. On the basis of such reaction condition, intermittent current flow method was adopted d to further enhance the electrokinetic remediation effect. The cadmium removal rate in the soil was increased by 3.17%, 2.86% and 2.43%, respectively, and the electric energy consumption was decreased by 10.54%, 11.28% and 9.97%, respectively, suggesting that the method could effectively improve the removal rate of Cd and reduce energy consumption.

Electrokinetic Remediation of Heavy Metal Contaminated Soil Using Permeable Reactive Composite Electrodes

2012 ◽  
Vol 518-523 ◽  
pp. 361-368 ◽  
Author(s):  
Rong Bing Fu ◽  
Xin Xing Liu ◽  
Fang Liu ◽  
Jin Ma ◽  
Yu Mei Ma ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Metal Ions ◽  
Removal Efficiency ◽  
Heavy Metal Ions ◽  
Metal Removal ◽  
Heavy Metal Removal ◽  
Ph Control ◽  
Electrokinetic Remediation ◽  
Composite Electrodes ◽  
Remediation Process

A new permeable reactive composite electrode (PRCE) attached with a permeable reactive layer (PRL) of Fe0 and zeolite has been developed for soil pH control and the improved removal efficiency of heavy metal ions (Cd, Ni, Pb, Cu) from soil in electrokinetic remediation process. The effects of different composite electrodes on pH control and heavy metal removal efficiency were studied, and changes in the forms of heavy metals moved onto the electrodes were analyzed. The results showed that with acidic/alkaline zeolite added and renewed in time, the composite electrodes could effectively neutralize and capture H+ and OH- produced from electrolysis of the anolyte and catholyte, avoiding or delaying the formation of acidic/alkaline front in tested soil, preventing premature precipitation of heavy metal ions and over-acidification of soil, and thus significantly improved the heavy metal removal efficiency. Fe0 in composite electrodes could deoxidize and stabilize the heavy metal ions. After that capture and immobilization of the pollutants were achieved. The results also showed that, using "Fe0 + zeolite" PRCE in the cathode with timely renewal, after 15-day remediation with a DC voltage of 1.5 V/cm, the total removal rates of Cd, Pb, Cu and Ni were 49.4%, 47.1%, 36.7% and 39.2%, respectively.

Application of UV radiation for in-situ Cr(VI) reduction from contaminated soil with electrokinetic remediation

2021 ◽  
Vol 416 ◽  
pp. 125806
Author(s):  
Yi Zheng ◽  
Huilin Li ◽  
Qiu Yu ◽  
Lin Yu ◽  
Binquan Jiao ◽  
...  
Keyword(s):  
Uv Radiation ◽  
Contaminated Soil ◽  
Electrokinetic Remediation

Exchange electrode-electrokinetic remediation of Cr-contaminated soil using solar energy

2018 ◽  
Vol 190 ◽  
pp. 297-306 ◽  
Author(s):  
Ming Zhou ◽  
Jingming Xu ◽  
Shufa Zhu ◽  
Yajing Wang ◽  
Hui Gao
Keyword(s):  
Solar Energy ◽  
Contaminated Soil ◽  
Electrokinetic Remediation

Lead (II) Removal from Contaminated Soils by Electrokinetic Remediation Coupled with Modified Eggshell Waste

2018 ◽  
Vol 777 ◽  
pp. 256-261 ◽  
Author(s):  
André Ribeiro ◽  
André Mota ◽  
Margarida Soares ◽  
Carlos Castro ◽  
Jorge Araújo ◽  
...  
Keyword(s):  
Contaminated Soil ◽  
Contaminated Soils ◽  
Removal Rate ◽  
Electrokinetic Remediation ◽  
Permeable Reactive Barrier ◽  
Inorganic Contaminants ◽  
Reactive Barrier ◽  
Eggshell Waste ◽  
Inorganic Fraction ◽  
Maximum Removal

Electrokinetic remediation deserves particular attention in soil treatment due to its peculiar advantages, including the capability of treating fine and low permeability materials, and achieving consolidation, dewatering and removal of salts and inorganic contaminants like heavy metals in a single stage. In this study, the remediation of artificially lead (II) contaminated soil by electrokinetic process, coupled with Eggshell Inorganic Fraction Powder (EGGIF) permeable reactive barrier (PRB), was investigated. An electric field of 2 V cm-1was applied and was used an EGGIF/soil ratio of 30 g kg-1 of contaminated soil for the preparation of the permeable reactive barrier (PRB) in each test. It was obtained high removal rates of lead in both experiments, especially near the cathode. In the normalized distance to cathode of 0.2 it was achieved a maximum removal rate of lead (II) of 68, 78 and 83% in initial lead (II) concentration of 500 mg-1, 200 mg-1 and 100 mg-1, respectively. EGGIF (Eggshell Inorganic Fraction) proved that can be used as permeable reactive barrier (PRB) since in all the performed tests were achieved adsorptions yields higher than 90%.

Impacts of Changing Operational Parameters of In Situ Chemical Oxidation (ISCO) on Removal of Aged PAHs from Soil

2012 ◽  
Vol 15 (2) ◽  
Author(s):  
Paula Cajal-Mariñosa ◽  
Ruth G. de la Calle ◽  
F. Javier Rivas ◽  
Tuula Tuhkanen
Keyword(s):  
Hydrogen Peroxide ◽  
Removal Efficiency ◽  
Contaminated Soil ◽  
Chemical Oxidation ◽  
Contaminant Removal ◽  
Operational Parameters ◽  
In Situ Chemical Oxidation ◽  
Different Types ◽  
Wood Impregnation

AbstractThe removal efficiency of two different types of peroxide addition, catalyzed hydrogen peroxide (CHP) and sodium percarbonate (SPC) were compared on a highly PAH-contaminated soil from a wood impregnation site. In an attempt to simulate real in situ reagents delivery, experiments have been carried out in acrylic columns. The main parameters affecting contaminant removal were the reagent’s temperature and the total addition of peroxide (g

scholarly journals Copper and Lead Ions Removal by Electrocoagulation: Process Performance and Implications for Energy Consumption

2021 ◽  
Vol 10 (3) ◽  
pp. 415-424
Author(s):  
Aji Prasetyaningrum ◽  
Dessy Ariyanti ◽  
Widayat Widayat ◽  
Bakti Jos
Keyword(s):  
Heavy Metals ◽  
Energy Consumption ◽  
Removal Efficiency ◽  
Current Density ◽  
High Current Density ◽  
Energy Requirement ◽  
Lead Ions ◽  
Initial Concentration ◽  
Electroplating Wastewater ◽  
Electrocoagulation Process

Electroplating wastewater contains high amount of heavy metals that can cause serious problems to humans and the environment. Therefore, it is necessary to remove heavy metals from electroplating wastewater. The aim of this research was to examine the electrocoagulation (EC) process for removing the copper (Cu) and lead (Pb) ions from wastewater using aluminum electrodes. It also analyzes the removal efficiency and energy requirement rate of the EC method for heavy metals removal from wastewater. Regarding this matter, the operational parameters of the EC process were varied, including time (20−40 min), current density (40−80 A/m2), pH (3−11), and initial concentration of heavy metals. The concentration of heavy metals ions was analyzed using the atomic absorption spectroscopy (AAS) method. The results showed that the concentration of lead and copper ions decreased with the increase in EC time. The current density was observed as a notable parameter. High current density has an effect on increasing energy consumption. On the other hand, the performance of the electrocoagulation process decreased at low pH. The higher initial concentration of heavy metals resulted in higher removal efficiency than the lower concentration. The removal efficiency of copper and lead ions was 89.88% and 98.76%, respectively, at 40 min with electrocoagulation treatment of 80 A/m2 current density and pH 9. At this condition, the specific amounts of dissolved electrodes were 0.2201 kg/m3, and the energy consumption was 21.6 kWh/m3. The kinetic study showed that the removal of the ions follows the first-order model.

scholarly journals Effect of chelating agents on removal of 137Cs from contaminated soil

2018 ◽  
Vol 15 (35) ◽  
pp. 158-168
Author(s):  
Firas M. Radhi
Keyword(s):  
Removal Efficiency ◽  
Contaminated Soil ◽  
Chelating Agents ◽  
Soil Samples ◽  
Coarse Grained ◽  
Tetraacetic Acid ◽  
Mixing Ratio ◽  
Soil Mixing ◽  
Chemical Washing ◽  
Washing Method

In the present research, the chemical washing method has been selected using three chelating agents: citric acid, acetic acid and Ethylene Diamine Tetraacetic Acid (EDTA) to remove 137Cs from two different contaminated soil samples were classified as fine and coarse grained. The factors that affecting removal efficiency such as type of soil, mixing ratio and molarity have been investigated. The results revealed that no correlation relation was found between removal efficiency and the studied factors. The results also showed that conventional chemical washing method was not effective in removing 137Cs and that there are further studies still need to achieve this objective.

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