Evaluation of Uncertainty in the Determination of Ozone Concentration in the Air by Sodium Indigo Disulfonate Spectrophotometry

The uncertainty of the determination of ozone concentration in the air at a workplace by sodium indigo disulfonate spectrophotometry was evaluated.The results show that the expanded uncertainty of ozone concentration U was 0.016 mg/m^(3),and the main factor affecting the measurement uncertainty of ozone concentration was the uncertainty introduced during sample collection.

Concentration-and flux-based dose-responses of isoprene emission from poplar leaves and plants exposed to an ozone concentration gradient

Supported by the National Key Research and Development Program of China,Key Research Program of Frontier Sciences,CAS,the Hundred Talents Program,Chinese Academy of Sciences(CAS),and National Natural Science Foundation of China,a cooperative study by the research groups led by Prof.

Relations between Climatic Changes and High Pollution Levels in Bulgaria

One of the important consequences of the climatic changes is the potential danger of increasing the concentrations of some pollutants, which may cause damages to humans, animals and plants. Therefore, it is worthwhile to study carefully the impact of future climate changes on the high pollution levels. The major topic of the discussion in this paper is the increase of some ozone levels in Bulgaria, but several related topics are also discussed. The particular mathematical tool applied in this study is a large-scale air pollution model, the Unified Danish Eulerian Model (UNI- DEM), which was successfully used in several investigations related to potentially dangerous pollution levels in several European countries. This model is described by a non-linear system of partial differential equations, which is solved numerically by using (a) advanced numerical algorithms and (b) modern computer architectures. Moreover, (c) the code is parallelized and (d) the cache memories of the available computers are efficiently utilized. It is shown that in Bulgaria, as in the other European countries, the climatic changes will result in permanent increases of some quantities related to the ozone pollution. The important issue is that in our study the changes of the dangerous pollution levels are followed year by year. In this way, an attempt is made both to capture the effect of the interannual variations of the meteorological conditions on the levels of the ozone concentrations and to follow directly the influence of the climatic changes on the pollution levels. Moreover, the sensitivity of the pollution levels to variations of the human made (anthropogenic) and natural (biogenic) emissions is also discussed.

Degradation of o-dichlorobenzene by DBD-NTP co-modified titanium gel catalyst

In order to study the degradation process of dioxins in industrial flue gas,the decomposition of o-dichlorobenzene(o-DCB)in a DBD plasma catalytic reactor was investigated.The results showed that an NTP-catalyzed system,especially using the Cu Mn Ti Oxcatalyst,had better o-DCB degradation performance compared to plasma alone.The combination of the Cu Mn Ti Oxcatalyst with NTP can achieve a degradation efficiency of up to 97.2%for o-DCB;the selectivity of CO and CO_(2)and the carbon balance were 40%,45%,and 85%,respectively.The dielectric constant and electrical property results indicated that the surface discharge capacity of the catalysts played a major role in the degradation of o-DCB,and a higher dielectric constant could suppress the plasma expansion and enhance the duration of the plasma discharge per discharge cycle.According to the O1s XPS and O_(2)-TPD results,the conversion of CO to CO_(2)follows the M-v-K mechanism;thus,the active species on the catalyst surface play an important role.Moreover,the Cu Mn Ti Oxand NTP mixed system exhibited excellent stability,which is probably because Cu doping improved the lifetime of the catalyst.This work can provide an experimental and theoretical basis for research in the degradation of o-DCB by plasma catalyst systems.