많은 미생물들이 수용성 망간이온(Mn2+)을 불용성인 산화망간(Mn4+) 광물로 산화 침전시키는데, 이와 같은 생물학적 산화반응은 비생물학적 산화반응보다 훨씬 빠르게 일어난다. 이처럼 미생물에 의해 생성된 바이오 산화망간 광물은 표면의 강한 흡착성과 산화환원 반응을 통해 생지구화학 순환과 환경오염물질의 생물흡수도에 큰 역할을 한다. 본 논평은 양자역학의 밀도범함수 이론에 바탕을 둔 전산모사를 이용하여 산화망간 광물 표면의 독성금속 흡착의 자세한 기작과 망간원자 빈자리의 광화학적 역할을 새롭게 밝힌 최근 연구결과를 소개한다.

Atmospheric photochemistry of O3-NOX-RH were considered theoretically, to clarify the reasons for the different trends of between the formation of photochemical oxidants (OX) and its primary pollutants for the Low- and High-NOX regimes. Equations of OH, HO2, and production of ozone (O3) as a function of nitrogen oxides (NOX) and reactive hydrocarbons (RH) were represented in this study. For the Low-NOX regime, HO2 radical is proportional to RH but independent of NOX. OH radical is proportional to NOX but inversely-proportional to RH. O3 production is proportional to NOX but has a weak dependence on RH. For the High-NOX regime, OH and HO2 radicals concentrations and O3 production are proportional to RH but inversely-proportional to NOX. In addition, the Osaka Bay and surrounding areas of Japan were evaluated with the mass balance of odd-hydrogen radicals (Odd-H) using CBM-Ⅳ photochemical mechanism, in order to distinguish the Low- and High-NOX regimes. The Harima area (emission ratio, RH/NOX = 6.1) was classified to the Low-NOX regime. The Hanshin area (RH/NOX = 3.5) and Osaka area (RH/NOX = 4.3) were classified to the High-NOX regime.

This study examines the local ozone photochemistry in the urban air. The photochemical formation and destruction of ozone was modeled using a photochemical box model. For the model prediction of ozone budget, measurements were carried out from an urban monitoring station in Seoul (37.6˚N, 127˚E), Korea for intensive sampling time period (Jun. 1～15, 2003). Photochemical process is likely to play significant role in higher ozone concentrations during the sampling period. The results of model simulation indicated that photochemical ozone production pathway was the reaction of NO with HO2 while ozone destruction was mainly controlled by a photochemical destruction pathway, a reaction of H2O with O(1D). The contribution of NMHCs to formation and destruction of ozone in the urban was significant. This was entirely different from remote marine environment. The rates of net photochemical ozone production ranged from 0.1 to 1.3 ppbv h-1 during the study period.