As (v) immobilization in an aqueous solution by zerovalent iron under various environmental conditions

영가철(Zerovalent Iron)을 이용한 수용액 중 비소(V)의 불용화

Zerovalent iron (ZVI) has been widely used in the removal of environmental contaminants from water. The objective of this research was to assess the efficiency of ZVI for immobilization of As (V) in the contaminated water under various chemical conditions. Batch-type experiments showed that the immobilization process followed a first-order kinetic model. Rate constant (k) of the reaction increased consistently and proportionally as increasing ZVI concentrations from 1% (0.158 $hr^{-1}$) to 3% (0.342 $hr^{-1}$), and temperatures from $15^{\circ}C$ (0.117 $hr^{-1}$) to $35^{\circ}C$ (0.246 $hr^{-1}$), respectively. Whereas the rate constant decreased as increasing As (V) concentrations from 1 mg $\Gamma^{-1}$ (0.284 $hr^{-1}$) to 3 mg $\Gamma^{-1}$ (0.153 $hr^{-1}$), and the initial pH from 3 (0.393 $hr^{-1}$) to 9 (0.067 $hr^{-1}$), respectively. Results demonstrated that As (V) in an aqueous solution was rapidly immobilized by ZVI treatments. Zerovalent iron was fast method for remediation of As (V) contaminated water.

본 연구의 목적은 비소로 오염된 수질을 영가철(ZVI)을 이용하여 복원하는 과정에서 pH, 온도, 초기 비소농도, 영가철량 등 다양한 환경요인별 영가철 기술의 효율성을 평가하는데 있다. 영가철에 의한 비소의 불용화 반응은 일차반응속도를 따랐으며 반응상수(k)는 ZVI의 처리농도가 증가할수록(1%: 0.158, 2%: 0.257, 3%: 0.342 $hr^{-1}$), 그리고 반응온도가 높을수록($15^{\circ}C$: 0.117, $25^{\circ}C$: 0.202, $35^{\circ}C$: 0.246 $hr^{-1}$)증가하였다. 반면 비소의 불용화 반응은 초기 As(V)의 농도가 낮을수록(1 mg $\Gamma^{-1}$: 0.284, 2 mg $\Gamma^{-1}$: 0.202, 3 mg $\Gamma^{-1}$: 0.153 $hr^{-1}$), 그리고 반응 pH가 낮을수록(pH 3: 0.393, pH 5: 0.213, pH 7: 0.097, pH 9: 0.067 $hr^{-1}$)증가하였다. 이상의 연구 결과를 통하여 비소로 오염된 물에 다양한 환경조건(pH, 처리량, 오염물질의 농도, 반응온도) 하에서 영가철을 적용하기 위한 최적 인자를 도출하였다.