최근 전 세계적으로 지하수 내 수계 망간(Mn) 농도가 증가하면서, 이에 따른 인체 건강 피해가 우려되고 있다. 특

히 인체 내 망간 농도가 기준치를 초과할 경우, 신경계 이상이나 아동의 발달 장애 등을 유발할 수 있다. 수계 망간 제

거를 위해서는 망간 산화를 통한 망간산화물 생성이 필요하지만, 비생물적 망간 산화 속도가 매우 느리기 때문에 효과

적인 제거가 어렵다. 본 연구에서는 자연 환경에서 풍부하게 발생하는 goethite를 광촉매로 사용하여, 비생물적 환경에

서의 Mn2+(aq)의 빠른 산화 반응을 확인하였으며, 광촉매 반응 간 온도 영향을 분석하였다. 빛을 받은 조건에서는 산

화가 뚜렷하게 발생한 반면, 빛을 차단한 조건에서는 망간 산화가 거의 일어나지 않았다. 또한, 해수 조건보다 지하수

조건에서 망간 산화 속도가 더 빨랐으며, 온도가 높을수록 Mn2+(aq)의 산화속도가 증가하는 경향을 보였다. XPS 분석

을 통해 온도가 높을수록 goethite표면에 형성된 망간산화물의 평균산화수가 높게 나타나는 것을 확인하였다. 또한 각

온도에서 반응속도계산 및 상수값 도출을 수행하였으며, 이를 통해 goethite 광촉매 반응에 의한 망간 산화 활성화 에

너지(48.71kJ/mol)와 빈도 인자(0.76M/s)를 도출하였다. 본 연구 결과는 광촉매 기반 망간 산화를 통해 지속가능한 방

식으로 지하수 내 망간 농도를 효과적으로 제어할 수 있음을 제시한다.

Recently, increasing manganese (Mn) concentrations in groundwater have raised global concerns due to

their potential effects on human health. In particular, Mn concentrations exceeding regulatory limits can cause neurological

disorders and developmental impairments in children. Effective removal of aqueous Mn requires its oxidation to form

insoluble Mn oxides. However, abiotic Mn2+(aq) oxidation proceeds very slowly under environmental dark conditions,

which limits its practical applicability for water treatment. In this study, we employed goethite as a photocatalyst to

demonstrate rapid Mn2+(aq) oxidation under abiotic conditions and systematically investigated the effect of temperature

on the photocatalytic reaction. UV–Vis analysis revealed pronounced Mn oxidation under illuminated conditions, whereas

negligible oxidation occurred in dark. In addition, Mn oxidation proceeded more rapidly in artificial groundwater than in

artificial seawater, and the Mn2+(aq) oxidation rate increased with increasing temperature. XPS analysis further showed

that higher temperatures led to an increase in the average oxidation state of Mn oxides formed on the goethite surface.

We also calculated reaction rate constants at different temperatures and derived an activation energy of 48.71 kJ/mol and

a pre-exponential factor of 0.76 M/s for the Mn2+(aq) oxidation driven by the goethite photocatalytic reaction. Overall,

our results demonstrate that photocatalytic Mn2+(aq) oxidation provides an effective and sustainable approach for

remediation of Mn2+(aq) contaminations under environmental aqueous conditions.

Manganese, Goethite, Photocatalytic oxidation, Temperature effect, Mn oxide

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