계면동전위라 불리는 제타전위(zeta potential)란 표면 전하적 특성을 정량화 한 값으로 전기동역학적 현상으로 발 생하는 전위차를 말한다. 제타전위는 막오염(fouling)과 표면전하 분석을 통한 개질 확인 및 치환기 확인에 대한 연구가 활발 히 진행되어 왔다. 그리고 제타전위를 측정하는 방법으로는 전기영동(electrophoresis), 전기삼투(eletrosmosis), 유동전위 (streaming potential)를 기초로 개발되었고, 그중에서도 평막은 유동전위 측정이 적합하다고 알려졌다. 따라서, 본 연구에서는 poly(styrene-ethylene-butylene-styrene) 고분자에 암모늄을 도입하여 아민화된 SEBS 평막 형택의 분리막을 제조하고, 계면동 전위 측정기를 이용하여 제조된 분리막들의 유동전위를 측정하여 결과를 분석하였다.
In the removal of heavy metals from the mine deposit using electrokinetic processes, the effects of operation under both constant current and constant potential conditions were estimated.
The results of soil pH distributions for DDW-20 V and DDW-100 ㎃ cases after the electrokinetic remediation tests were observed. In the former case, soil pH was not much changed and kept to almost constant value just little higher than initial soil pH of 3.52, except near the cathode, which was about pH 5. While in the latter case, soil pHs of anode and the cathode regions were less than pH 3 and about 6, respectively.
The electroosmotic flow to the cathode increased rapidly till 10 hrs and decreased steadily and then maintained to constant rate until the end of operation at constant current condition. Electric potential gradient was continuously increased to as much as 34.375 V/cm. At the steady state, values of the apparent electric conductivity for DDW-20 V and DDW-100 ㎃ were around 40 ㎲/㎝ and 30 ㎲/㎝, respectively.
In the DDW-100㎃ test, Cu, Cd, and Zn except Pb showed the tendency of moving toward the cathode. While in the DDW-20 V case, it was observed that Cu, Zn, and Pb except Cd were not moved to any directions. The results of the tests demonstrated that the electrokinetic soil remediation process could be operated better under constant current condition than constant electric potential condition.
Electrokinetic remediation technique offers the opportunity to extract heavy metals from soils with high plasticity. The experiment demonstrated the applicability of electrokinetic remediation on metal-mining deposit and the decision of the enhancement method for four kinds of bench-scale studies. According to the sequential extraction of heavy metals in the "I" mining deposit, Pb and Cu were mostly associated with residual fraction and Zn and Cd were associated with water soluble and residual fraction. Therefore, removable fractions by electrokinetic technology was determined by the sum of the fraction of water soluble and exchangeable, which is Cu : 19.53 %, Pb : 1.42 %, Cd : 52.82 %, Zn : 57.28 %, respectively.
When considering electrical potential, volume of effluent, soil pH, and eliminated rate of contaminant, results determined by sum of each weight were Citric aic+SDS (13) > 0.1N HNO3 (10) > HAc (8) > DDW (4). Therefore, citric acid and SDS mixed solution was determined the best enhancing agent for the remediation of metal mining deposit.