Electrokinetic restoration of saline agricultural lands

Abstract

Salinization of greenhouse soils has become a serious problem in Korea because of the extensive use of chemical fertilizers to improve crop yield. This study investigated the feasibility of electrokinetic (EK) treatment for reclamation of saline soil. Experiments were conducted using voltage gradients of 1, 2, and 3 V/cm applied for 48 and 96 h. Anions such as chloride, sulfate, and nitrate were transported toward the anode and accumulated there, whereas cations were transferred toward the cathode by electromigration. Among the various ions, the highest removal efficiency was achieved for nitrate: [80% at 48 h and [99% at 96 h. Chloride removal after 96 h was substantially higher than that after 48 h because the longer period of time allowed more electrical transport via electromigration and electro-osmosis. However, the removal efficiency for sulfate and calcium did not change significantly between 48 and 96 h. Soil EC was lower than the initial value in all soil sections at 96 h. The lowest value, 1.8 dS/m, was seen in the experiment employing a gradient of 3 V/cm for 48 h. This study demonstrated that nitrate can be readily removed from soil by electromigration. Further, other ions can also be removed by EK treatment; therefore, it could be successfully used for reclamation of saline soils.

Pilot-scale ex situ electrokinetic restoration of saline greenhouse soil

“…Since nitrate is a slightly more reactive compound than chloride, it is probable that the transportation of nitrate through the upward movement of soil moisture was retarded as a result of its interaction with the soil particles. The sulfate removal efficiency, which was the lowest in the previously conducted lab-scale experiment (Cho et al 2009;Cho et al 2010), was considerably high among the anions in this study; furthermore, the removal of sulfate was uniform across all the layers (Fig. 8).…”

“…The main ingredients in a fertilizer are nitrate, phosphate, potassium, magnesium, and sulfate; these salts have high solubility and exist in ionic forms in the soil. Therefore, the use of EK treatment, which can enhance the transport of charged ions in the soil, is a suitable method to remove these salts (Cho et al 2009;Cho et al 2010;Jia et al 2005;Kim et al 2010).…”

A Field Study on Electrokinetic Removal of Salts from Greenhouse Soil

“…In conclusion, the in situ EK technique is feasible for the restoration of saline greenhouse soils in or no cultivation and an appropriate strategy is necessary for more effective remediation. 최근에는 이러한 전기동력학 기술을 시설재배지 토양의 염류 제 거에 적용하려는 다양한 시도가 이루어지고 있다 [6][7][8][9][10][11]. Cho et al, [6,7]은 실험실 규모의 EK 실험을 통해 시설재배지 토양의 주요 염 류인 Na …”

Electrokinetic Restoration of Saline Soil Accumulated with Nitrate and Sulfate

“…전기동력학적 정화기술은 이온성 오염물질을 토양 으로부터 제거하기 위해 고안된 방법이다 (박성우 외, 2008; 조정민 외, 2009; 박근용 외, 2010). 최근의 연구 결과에 의하면 전기동력학적 방법은 염류집적 토양에서 염류를 효과적으로 제거할 수 있다고 보고되었다 (Jia et al, 2005;Cho et al, 2009Cho et al, , 2010Cho et al, , 2011Ha et al, 2009;Kim et al, 2011;Lee et al, 2011). Cho et al(2009 (정병간 외, 1998).…”