This paper aims to find the characteristics of concentration distribution of coastal urban air pollutants. For this purpose, It was used the daily meteorological data and the hourly concentration data for O3 and NO2 in Busan metropolitan city from 1994 to 1996. It was investigated the annual and monthly distribution of ozone and nitrogen dioxide concentration at each site in Busan, and also investigated the characteristics of concentration change of air pollutants with time under the sea breeze.
As a results, the concentration of nitrogen dioxide and ozone tend to be increased every year and nitrogen dioxide concentration is higher than ozone concentration at all sites in Busan. The concentration of ozone is high in summer season and low in winter season, but the concentration of nitrogen dioxide have a reversed trend. The monthly peak concentration of ozone occurred in April and September, while the monthly minimum concentration of nitrogen dioxide occurred in August. Their trend were identified by sites near the coastline than sites stands apart from the coastline. The sea breeze occurred annual mean 81 day in Busan from 1994 to 1996. The main wind direction of sea breeze was classified into southwesterly and southeasterly. In case of southwesterly, It was pronounced the south wind and southwest wind. In case of southeasterly, the occurrence frequency of east wind was high. Especially, the concentrations of urban air pollutants, such as ozone and nitrogen dioxide, were high on time which the sea breeze flow, and the areas that ozone concentration was high moved from outside part to central part of city with time.
In costal urban such as Busan, the wind direction of sea breeze is influenced the change of ozone and nitrogen dioxide concentration on time which the sea breeze flow at each site and also influenced the change of air pollutants concentration of sites on the pathway of sea breeze.
The recycled washwater, which has different water quality and is produced about 5 to 20% of the total water volume treated, affects the unit operation of water treatment, especially coagulation process. However, the effects of recycled washwater on unit operation of water treatment have not been fully investigated. In this study, effects of recycled washwater on coagulation process were investigated to find the optimum coagulation condition by analyzing turbidity, UV254, TOC removal efficiencies. In addition, effects of recycled washwater on residual Al after coagulation were studied by analyzing soluble and particulate Al. The size distribution and fractal dimension of coagulated also analyzed.
The recycled washwater was lower pH than the raw water. And the recycled washwater had higher UV254, TOC and residual Al concentration than the raw water. Residual Al concentration of recycled washwater was about 50 times higher than that of raw water. Optimum coagulant dosages on the blending recycled washwater and the raw water for turbidity, UV254 and Al removal were lower than that on the raw water. However, TOC removal increased by increasing coagulant dosage. The size and fractal dimension of coagulated particle produced in the blending recycled washwater were larger, which imply faster settling velocity, than those produced in the raw water only.
The urban pollution if affected by local environmental, so it is necessary to consider area characteristics such as emission source and meteorological phenomena, in studying urban air pollution. Ulsan is laocated on south-east coast and has many industrial facilities, so many people have concerned about air pollution. This study contain conducting numerical simulation of air pollutant concentration considered land and sea breeze in Ulsan area with the numerical model.
The absorption of benzene in nonpolar solution was studied in a laboratory-scale of bubble column varying of gas flow rates and gas-to-liquid ratios. A bubble column had a 0.8~1×10-3 m3 total volume (height 1500 mm, diameter 50 mm). Solution analysis was performed by GC-FID and GC-MSD. The objectives of this research were to select the best absorption fluid and to evaluate the mass transfer characteristics under specific conditions of each absorption. The results of this research were follow as:
First, the heat transfer fluid is more efficient than the other nonpolar solution in removing VOC. Second, The benzene removal efficiency improved according to an increasing rate of gas flow. Also, volumetric mass transfer rate of column can be enhanced by increasing gas flow rate. Finally, the relation of gas flow rates, liquid amount, and volumetric mass transfer coefficient was obtained as follows.
Kya=0.5906(Vg/L)0.7611
The following correlation of mass transfer coefficient and efficiency was proposed.
η=0.06078 Kya0.2444
차광 및 광 강도별 맥문동의 광합성속도, 기공전도도 및 증산작용과 그 관련형질간의 상호연관성을 구명하였던 바는 다음과 같다. 맥문동의 광합성속도는 광 강도가 증가함에 따라 증가하였고 PAR 700-1000μmol/m2/s에서 최고치를 나타내었으며 차광에 의해 증가되는 경향이었다. 기공전도도는 광 강도가 증가함에 따라 증가되었고, 광합성속도, 증산작용 및 기공전도도의 일변화는 비슷한 경향의 양상을 띄었다. 광합성속도와 기공전도도와의 관계는 1차직선회귀관계로 고도의 정(正)의 상관이 인정되었으나 대조구와 차광구가 각각 다른 1차회귀직선을 보여 동일한 기공전도도에서 차광구의 광합성속도가 대조구보다 높은 경향으로 나타났다. 증산작용과 기공전도도 및 광합성속도와 증산작용의 관계는 양자간에 모두 1차회귀식의 정(正)의 상관관계가 인정되었다.
내분비계 장애물질은 다양한 동물의 생식과 배아의 발생에 위해한 영향을 미친다고 보고되었다. 이러한 초기 배아의 비정상 발생 중 대표적인 것이 할구파편이다. 본 연구에서는 착상 전 생쥐 초기 배아를 PCB, BPA, DDT에 체내, 체외에서 각각 노출시켰다. 내분비계 장애 물질에 노출시켰던 배아는 할구파편, 불규칙한 할구와 깨짐, 일부 파괴된 투명대 배아 등의 다양한 형태학적 비정상 양상을 보였다. 착상 전 생쥐 초기배아의 세포괴사에 관여하는 유전자를 조