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

Author(s):  
Zongping Cai ◽  
Yan Sun ◽  
Yanghong Deng ◽  
Xiaojie Zheng ◽  
Shuiyu Sun ◽  
...  

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.

2020 ◽  
Vol 10 (10) ◽  
pp. 3410 ◽  
Author(s):  
Elnaz Amirahmadi ◽  
Seyed Mohammad Hojjati ◽  
Claudia Kammann ◽  
Mohammad Ghorbani ◽  
Pourya Biparva

Today, it is very important to protect plants in soils contaminated with metals. We investigated the behavior of cadmium during the establishment of oak seedlings (Quercus castaneifolia C.A. Mey.) under biochar influence. This study was conducted in pots with loamy soil. Cadmium was added to soil at 0, 10, 30, and 50 mg per kg of soil, indicated by Control, Cd10, Cd30 and Cd50. Biochar was produced at 500–550 °C from rice husk and added at 1, 3, and 5% (wt/wt) levels, indicated by B1, B3, B5, and mixed with soil at planting in three replications. Generally, increasing biochar rates had significant effects on seedling height, diameter, and biomass. This coincided with Cd immobilization in the contaminated soil which reflects a decrease in Cd concentrations in the plant bioavailability of Cd. The tolerance index increased significantly, by 40.9%, 56%, and 60.6% in B1, B3, and B5 with Cd50, respectively, compared to polluted soil. The percent of Cd removal efficiency for Cd50 was 21%, 47%, and 67% in B1, B2, and B5, respectively. Our study highlights that biochar can reduce Cd bioavailability and improve the growth of oak seedlings in contaminated soil.


2012 ◽  
Vol 518-523 ◽  
pp. 361-368 ◽  
Author(s):  
Rong Bing Fu ◽  
Xin Xing Liu ◽  
Fang Liu ◽  
Jin Ma ◽  
Yu Mei Ma ◽  
...  

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.


2021 ◽  
Vol 416 ◽  
pp. 125806
Author(s):  
Yi Zheng ◽  
Huilin Li ◽  
Qiu Yu ◽  
Lin Yu ◽  
Binquan Jiao ◽  
...  

2018 ◽  
Vol 190 ◽  
pp. 297-306 ◽  
Author(s):  
Ming Zhou ◽  
Jingming Xu ◽  
Shufa Zhu ◽  
Yajing Wang ◽  
Hui Gao

2018 ◽  
Vol 777 ◽  
pp. 256-261 ◽  
Author(s):  
André Ribeiro ◽  
André Mota ◽  
Margarida Soares ◽  
Carlos Castro ◽  
Jorge Araújo ◽  
...  

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%.


2014 ◽  
Vol 627 ◽  
pp. 357-364 ◽  
Author(s):  
Goran Radovic ◽  
Vera Murgul ◽  
Nikolai Vatin ◽  
Ekaterina Aronova

The article deals with the concept of solar photovoltaic systems use in power supply systems. An analysis of local solar resources potential has been carried out, and optimal orientation points of radiant heat absorbing photovoltaic panels have been chosen to achieve maximum energy performance. Simulation of electric power systems having different configurations has been implemented using the software program Homer. It has been stated that a combination of solar and diesel energy systems is considered to be an optimal solution under the weather conditions of Montenegro. The systems working together make it possible to reduce maintenance costs significantly and adjust capacity generation schedule with due account for energy consumption features to a maximum extent. This allows generating electric power at less cost and results in a more reliable and continuous power supply without failures for a consumer chosen.


Author(s):  
Paula Cajal-Mariñosa ◽  
Ruth G. de la Calle ◽  
F. Javier Rivas ◽  
Tuula Tuhkanen

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


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