On increasing the importance of indoor air quality in urban schools of Korea, a comprehensive investigation of PM2.5 was carried out focusing on carbon contents. According to the analysis results, PM2.5 of the classrooms distributed 14.5 μg/m3 to 40.2 μg/m3, which was lower than National Guidelines (35 μg/m3 for 24 h average), and it contained 45.4 ± 10.9% of carbonaceous matters including organic carbon (OC) and elemental carbon (EC). Carbons were proportionally correlated with externally occurring ion species, but OC was found more inside (9.5 μg/m3) than outside (5.9 μg/m3). This indicates that school children are exposed to a variety of polymeric chemicals in the classroom. The current data obtained in this study can be used to inform the establishment of a national school air quality management policy.

Indoor air quality indices (IAQI-S, IAQI-C and IAQI-E) were developed to manage air quality in public facilities for vulnerable groups such as schools, child daycare centers, and elderly nursing homes, respectively. In this study, hazard quotient (HQ) was first designated, then the concentrations of each pollutant were calculated by adding the exposure factor of residents. The presented index was more stringent than comprehensive air quality index (CAI) for outdoor atmosphere. Also, composite indices that integrate individual indices for each pollutant were developed for quick and convenient recognition of the current air quality by administration officers or teachers and to take remedial actions. Among all data collected in field measurements, 75.4%, 71.2% and 35.6% were classified as ‘Good’ or ‘Moderate’ in school classrooms, child daycare centers and elderly nursing homes, respectively

Harmful heavy metals and carbonaceous substances contained in PM2.5 collected from 53 schools located in large Korean cities were closely analyzed based on the hypothesis that emission sources such as automobiles are coincident. The average concentration of PM2.5 from the analysis of all classrooms was 20.7 µg m -3 . Mn was the most prevalent heavy metal with a concentration of 0.018 µg m -3 , followed by Pb and Cu. The heavy metals were closely related to elemental carbon (EC) introduced mainly from the outside with a correlation coefficient of 0.556, showing consistent significance. Organic carbon (OC) showed a correlation coefficient of 0.357, which statistically supported the presence of obvious OC sources in the classroom. Overall school classroom contamination levels have been shown to be below national guideline.

The objective of this research is to investigate Fenton reaction, permanganate and persulfate oxidation as in-situ remediation technology for the treatment of gasoline-diesel contaminated soil. These oxidants were compared in various soils to study the influence of soil texture and soil organic matter. The different fractions of hydrocarbons, which have been scarcely investigated, were also analyzed and the compounds were clustered into aliphatic and aromatic hydrocarbons. Maximal removal rates were obtained with permanganate (74%), followed by persulfate (60%) and hydrogen peroxide (55%). High levels of clay in the soil (silty clay soil) reduced the efficiency of permanganate and persulfate hydrocarbon oxidation by 18%. On the other hand, 5% soil organic matter decreased the effectiveness of permanganate (18%). The removal rates of hydrocarbons decreased while hydrocarbon size increased, and aromatic hydrocarbons were more oxidized than aliphatic ones. In general, elimination percentages higher than 80% are achieved for chains >C6-C8 and lower than 20% for those in the range >C21-C35.The results observed can be used to increase the efficiency and improve the design of advanced oxidation processes for treating gasoline and diesel contaminated soil.

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