Four types of metal oxide semiconductor gas sensor arrays were used to observe the aroma and spoilage odor emitted during the ripening process of plum & banana fruits. All gas sensors showed a high correlation (R=0.82~0.90) with the olfactory. The TGS 2603 sensor showed a high correlation of 0.90 between the odor generated and sensory perception of smell in the process of ripening and decaying fruits. In addition, it showed a very high correlation of 0.91 with the decay rate of the plum sample, and the significance probability through one-way ANOVA was also less than 0.05, which confirmed it as an optimal gas sensor (TGS 2603). Principal component analysis was performed using all the data. The cumulative variability was 99.54%, which could be explained only by two principal components, and the first principal component was 95.11%, which was related to the freshness of the fruit. It was analyzed as fresh fruit in the negative(-) direction and decayed fruit in the positive(+) direction.

The changes in the aroma and spoilage odor emitted from eleven ‘Hongro’ apples during ten weeks’ storage were investigated using six types of metal oxide semiconductor gas sensor arrays. The gas sensors used in the evaluation were sensitive to apple-emitted aroma or spoilage odor, and a high reproducibility of 5% relative standard deviation or less was confirmed. Significantly, the change in apple-emitted aroma or spoilage odor was easily distinguished by the optimal gas sensor and a significant correlation (r=0.992) between decay rate and sensitivity change was observed. The results of a principal component analysis of the signal patterns obtained by data standardization using the optimal gas sensor showed a clear classification between decayed sampler groups and undecayed sampler groups.

This study was designed to assess the odor characteristics of paprika with metal oxide gas sensors. Non-decayed paprika and decayed paprika were assessed by sensor array system comprising 10 kinds of sensors. Three representative sensors were selected from among the 10. Selection was based on a correlation analysis between sensors from the results of the sensor array assessment on non-decayed paprika. It was found that the odor variation characteristics of paprika can be assessed by metal oxide gas sensors and that the odor variation characteristics of paprika are different depending on the type of gas sensors. The odor characteristics of paprika were different according to the color, the presence or absence of decay, the location of decay, the type of sensor, and the passage of time. Regardless of decay, the sensor response value of orange paprika was the highest, with the 2611 sensor yielding the highest response value. The SB-AQ1 sensor could not identify the difference in odor characteristics depending on the location of decay, while detection was possible by both SB-41 and 2611 sensors.

The correlation analysis between odor sensor and air dilution olfactometry method with odor emission facilities was performed for the real-time evaluation of odor emitted from the 13 facilities. The total correlation was less significant for all facilities due to various emission characteristics of odor. The correlation for the individual facility, however, showed a higher correlation coefficient (R=0.7371~0.9897). Especially, the strong correlation (above 0.9) was observed for the industry type with the odor characteristics like tobacco, styrofoam, acetic acid, and burning smell. The repeated odor measurements using the odor sensor showed good reproducibility with the mean relative standard deviation of 5.06%. The odor sensor could be useful tools for identifying and evaluating odor with an olfactometry in field, if the use and proofreading of the odor sensor are improved by a standardized method.

Soil column experiments were evaluated effects of silver nanoparticles (i.e., 0, 2.5, 5, and 10 mg/L) on the microbial viability which is strongly associated with the degradation of organic matter, pharmaceutically active compounds(PhACs) and biological oxidation of nitrogenous compounds during river bank filtration. The addition of silver nanoparticles resulted in almost no change in the aqueous matrix. However, the intact cell concentration decreased with addition of silver nanoparticles from 2.5 to 10 mg/L, which accounted for 76% to 82% reduction compared to that of control (silver nanoparticles free surface water). The decrease in adenosine triphosphate was more pronounced; thus, the number and active cells in aqueous phase were concurrently decreased with added silver nanoparticles. Based on the florescence excitation-emission matrix and liquid chromatograph - organic carbon detection analyses, it shows that the removal of protein-like substances was relatively higher than that of humic-like substances, and polysaccharide was substantially reduced. But the extent of those substances removed during soil passage was decreased with the increasing concentration of silver nanoparticles. The attenuation of ionic PhACs ranged from 55% to 80%, depending on the concentration of silver nanoparticles. The attenuation of neutral PhACs ranged between 72% and 77%, which was relatively lower than that observed for the ionic PhACs. The microbial viability was affected by silver nanoparticles, which also resulted in inhibition of nitrifiers.

The application of gas sensors for the measurement of environmental odor was investigated. The test chamber systems were consist of three parts, as it were, sample injection, odor sensing and data process parts. Four type of sensors were tested with regard to sensor performance like baseline stability, sensitivity and reproducibility to H₂S, CH₃SH, NH₃, and (CH₃)₃N gases. As the results, two kinds of sensors were content with the circuit conditions used in this study. In addition, the influence of relative humidity to the selected two types sensors was tested. The [mal sensor, which was appeared to be the most stable sensor against relative humidity, was selected, and applied practically to measure the real odor from the manure odor source.

우리 나라의 먹는물 검사항목에 지정되지 않은 32가지 오염물질의 원수에 대한 분포에 대하여 1997년과 1998년사이에 조사되었다. 조사대상 물질은 16가지 휘발성 유기물질과 7가지 유기인계 농약 그리고 8가지의 중금속과 우라늄 등이었다. Chlorobenzene, 1, 4-Dichloro- benzene, 1, 3-Dichloropropane이 휘발성 유기물질 중에서 0.03~1.33 μg/l 범위에서 검출되었다. Sr과 Ba, B은 다른 중금속들에 비해 상대적으로 높은 농도로 나타 났고, 검출 평균농도는 Sr이 25~60 μg/l, B는 약 5~40 μg/l 농도범위로 나타났다. Tl, Ni, Be, Mo, Sb과 U은 미 량 혹은 검출한계 이하의 값으로 조사되었다. Lindane 을 포함한 일곱가지 유기염소계 농약의 경우 1998년 한 해 동안 25개 조사대상지점에서 모두 검출한계 이하의 값으로 조사되었다. Chlorobenzene, 1, 4-Dichlorobenzene, Ba, B에 대한 WHO의 권고기준치는 모두 300 μg/l으로서 이번에 검출된 물질의 농도는 모두 이 기준치 이하로 나타 났다. 이 결과는 이들 조사 대상 항목으로 인한 원수의 오염 가능성이 매우 낮음을 보여준다.