Determination of O3, NO2, SO2, CO and PM10 measured in Belgrade urban area

O(3), NO(2), SO(2), CO and PM(10) concentrations, simultaneously determined for the first time in Belgrade urban area in the autumnal period of 2005, are presented. The obtained results display similar behaviour of SO(2), NO(2), CO, PM(10) opposite from that of O(3). The weekend effect was also investigated showing diminution of average daily concentrations of SO(2), NO(2), PM(10) and CO for 72, 40, 37 and 42% respectively, and increase of the average daily concentration of O(3) for 56%. Influence of meteorological conditions on observed concentration levels was studied, too. The observed influence of wind speed on the O(3) nightly concentration levels was analyzed pointing to the phenomena of O(3) transport during episodic measurements. To make an identification of possible pollution sources and analyse the influence of meteorological parameters on pollution levels, air back trajectories for high level concentrations episodes were calculated and analysed. A multivariate receptor modelling (Principal Component Analysis, Cluster Analysis) has been applied to a set of data in order to determine the contribution of different sources. It was found that the main principal components, extracted from the air pollution data, were related to gasoline combustion, oil combustion and ozone transport.     

Long-term relationships between SO2 and NOx emissions and SO4(2-) and NO3- concentration in bulk deposition at the Hubbard Brook Experimental Forest, NH

A highly significant second-order polynomial relation between SO(2) emissions and SO(4)(2-) concentrations during 1970-2000 (r(2)= 0.80, p= <0.001), and a linear relation between NO(x) and NO(3)(-) concentrations during 1991-2000 (r(2)= 0.67, p= 0.004) in bulk precipitation were found for the Hubbard Brook Experimental Forest, NH based on emissions from a 24 h, back-trajectory determined source area. Earlier periods (1965-1980) for SO(2)ratio SO(4)(2-) and longer periods (1965-2000) for NO(x)ratio NO(3)(-) had poorer linear relations, r(2)= 0.03, p= 0.51 and r(2)= 0.22, p= 0.004, respectively. Methodology by the US Environmental Protection Agency for calculating emissions data during this period has changed significantly and frequently, making trend analysis difficult. Given the large potential for errors in estimating emissions and to a lesser extent, deposition, the robust relations between SO(2) emissions and SO(4)(2-) concentrations in bulk precipitation at the Hubbard Brook Experimental Forest show that careful, long-term measurements from a single monitoring site can provide sound and reasonable data on trends in air pollution.     

Light non-methane hydrocarbons at two sites in the Indo-Gangetic Plain

Measurements of light (C(2)-C(5)) non-methane hydrocarbons (NMHCs) were made along with ozone (O(3)), oxides of nitrogen (NO(x)), carbon monoxide (CO) and methane (CH(4)) at Hissar and Kanpur in the Indo-Gangetic Plain (IGP) in India during the month of December, 2004. Air samplings during noon and evening hours provided an opportunity to study the emission characteristics and changes during this period at these sites. The mixing ratio of O(3) was higher during noon hours due to photochemical formation, while the levels of precursor gases showed elevated values during the evening hours on a clear sky day. On foggy days there is no such variation. The lower mixing ratios of O(3) observed on foggy days could be due to the slower rate of photochemical formation caused by a reduction in solar flux and surface deposition caused by the presence of a stable planetary boundary layer. Propene and ethene show the highest evening to noon ratio due to their faster reactivities with OH radicals. Correlations among different species of the measured gases indicate contributions of emissions from biomass and biofuel burning as well as fossil fuel combustion. Although qualitatively in relation to O(3), the propylene (propene) equivalents of NMHCs have been calculated to investigate their roles in O(3) photochemistry and compared with the data from Ahmedabad, an urban site in western India. The important result, which has emerged from the analysis of the observed data, is that while the total amount of these NMHCs is least at Hissar and highest at Ahmedabad, the total propylene-equivalent is highest at Hissar and lowest at Ahmedabad. Further, these two sites in the IGP show significant contributions, almost 72-77%, by propene and ethene while the contribution by these two gases at Ahmedabad is only about 47%. The surface level mixing ratios of O(3) could be treated as representative for the chemical characterization of air mass at a regional scale over the IGP as the month long trends of O(3) show significant similarity compared to the trends in precursors at the two sites.     

Influence of Meteorological Factors NO2, SO2, CO and PM10 on the Concentration of O3 in the Urban Atmosphere of Eastern Croatia

Ozone, NO₂, SO₂, CO, PM₁₀ and meteorological parameters were measured simultaneously during the summer?Cautumn season 2007 in Osijek??the eastern, flat, agricultural part of Croatia. Fourier analysis confirms the existence of variation in ozone volume fractions with periods ranging from the usual semi-daily and daily to 7 and 28 daily cycles. The relationships between O₃ and other variables were modelled in three ways: principal component analysis, multiple linear regression and principal component regression. The results of the principal component analysis detected underlying relationships among ozone concentrations and meteorological variables. An extremely simple meteorological model is suitable for the prediction of ozone levels. The meteorological factors, temperature and cloudiness played a main role in the MLR model (R ²?=?0.83). The application of the principal component regression approach confirmed that the original variables associated with the valid principal components were meteorological variables (R ²?=?0.82).     

差分光谱法连续监测空气中SO2、NO2、苯、甲苯方法探讨

差分光谱法(简称DOAS)已广泛用于空气中SO2、NO2、苯、甲苯监测.通过对差分光谱法监测结果与其他传统仪器进行时比,发现用DOAS监测SO2、NO2与点式仪器有较好的一致性,但用DOAS系统监测苯、甲苯与气相色谱法有机物连续监测结果差异较大,相关性较差,运行有一定的局限性.另外,本文对DOAS的最佳运行条件进行了探讨,发现影响光强的氙灯老化和气候条件对DOAS系统运行有较大影响.     

Concentrations, distributions and critical level exceedance assessment of SO2, NO2 and O3 in South Africa

South Africa has been identified as a source of industrial pollution that is significant at a global scale. This study was designed to provide quantitative information, by direct measurement, across northeastern South Africa, which includes the highly industrialised Mpumalanga Highveld. The specific aim of the study was to evaluate whether or not acidic atmospheric pollution poses a threat to soils, plants and water bodies of South Africa. To address this aim, a network of 37 passive sampling sites was established to measure monthly mean concentrations of near-surface SO₂, NO₂ and ozone. The area covered extended over the northern and eastern interior of South Africa while avoiding sources of local emissions such as towns, mines and highways. The field campaign was conducted between August 2005 and September 2007. Spatial distributions and temporal trends for these pollutant gases were assessed. Critical levels analysis comparisons were made against applicable air quality standards, guidelines and limits to evaluate the potential for adverse atmospheric pollution impacts on regional environments. The assessment indicates that only in the central source area of the South African industrial Highveld are some levels exceeded. In remote areas, including the sensitive forested regions of the Drakensberg escarpment, pollutant concentrations are below the critical thresholds for environmental damage.     

Growth impact of O3, NO2 and/or SO2 on pinus taeda

Seedlings of two full-sib families of loblolly pine expressing different degrees of sensitivity to O₃ were exposed to 0.05 ppm O₃, 0.10 ppm NO₂, and/or 0.14 ppm SO₂ for 6 hr/day for 28 consecutive days. The treatments were O₃, NO₂, SO₂ (each used alone), O₃+SO₂, O₃+NO₂, and O₃+NO₂+SO₂. Significant growth suppressions were noted with the relatively sensitive family in all but the the NO₂ alone treatments. The O₃+SO₂ treatment had a more significant effect than O₃ alone, but adding NO₂ had an inconsistent effect. Significant growth suppressions were noted for the relatively non-sensitive family only in the O₃+SO₂ and O₃+SO₂+NO₂ combination treatments. Adding NO₂ to O₃+SO₂ had a slightly stimulatory effect. The relatively sensitive pine family suffered a 30% height growth suppression versus a 14% height growth suppression for the relatively insensitive family when exposed to the 3 pollutant combination. Symptoms were noted on less than 4% of the foliage in the most severe treatments. The pollutant concentrations used in this study were below the National Ambient Air Quality Standards (NAAQS) for each pollutant.     

Measurements of SO2, NO X and SPM in an industrial area at the Aegean coast of Turkey

Data from continuous measurements of SO₂ NO _x , suspended particulate matter (SPM) and meteorological parameters at seven sites around a highly industrialized region in the Aegean coast of Turkey, between July 15, 1991 to July 31, 1992 were used to evaluate spatial and temporal variations of air quality parameters. Low annual averages and insignificant differences between day and night concentrations were observed at stations far from sources. At stations close to sources, annual average concentrations were high and diurnal patterns were significant. Annual average SO₂ and SPM concentrations in all stations used the Krigging technique to assess the impact of industries on air quality in the surrounding airshed. Results have demonstrated that Turkish air quality standards for SO₂ were exceeded in a circle with a radius of 4 km and which was centered on the petrochemical complex and refinery. Similarly, standards for SPM were exceeded in a circle with a radius of 1.2 km and which was centered on the ironwork plants. Both SO₂ and SPM showed well defined diurnal variations, particularly in stations close to sources. The SO₂ concentrations showed a maximum during day-time, while SPM concentrations peaked after midnight. Although annual average SO₂ and SPM concentrations were highly variable depending on distances between stations and sources, background concentrations of the same pollutants, calculated by stripping episodes from data, did not change significantly from one station to another. Long range transport and resuspension of local soil were suggested as sources of background SO₂ and SPM, respectively. The difference between observed and background concentrations of SO₂ and SPM in each station was related to the impact of industries on air quality at that particular site.     

Aircraft mass budgeting to measure CO2 emissions of Rome,Italy

Aircraft measurements were used to estimate the CO₂ emission rates of the city of Rome, assessed against high-resolution inventorial data. Three experimental flights were made, composed of vertical soundings to measure Planetary Boundary Layer (PBL) properties, and circular horizontal transects at various altitudes around the city area. City level emissions and associated uncertainties were computed by means of mass budgeting techniques, obtaining a positive net CO₂ flux of 14.7?±?4.5, 2.5?±?1.2, and 10.3?±?1.2 μmol m^?2 s^?1 for the three flights. Inventorial CO₂ fluxes at the time of flights were computed by means of spatial and temporal disaggregation of the gross emission inventory, at 10.9?±?2.5, 9.6?±?1.3, and 17.4?±?9.6 μmol m^?2 s^?1. The largest differences between the two dataset are associated with a greater variability of wind speed and direction in the boundary layer during measurements. Uncertainty partitioned into components related to horizontal boundary flows and top surface flow, revealed that the latter dominates total uncertainty in the presence of a wide variability of CO₂ concentration in the free troposphere (up to 7 ppm), while it is a minor term with uniform tropospheric concentrations in the study area (within 2 ppm). Overall, we demonstrate how small aircraft may provide city level emission measurements that may integrate and validate emission inventories. Optimal atmospheric conditions and measurement strategies for the deployment of aircraft experimental flights are finally discussed.     

Reduction of SO2 emissions by ammonia gas during unstaged combustion

The reduction of SO₂ by the addition of ammonia gas has been studied in a 2 m high fluidized bed combustor having a 30 cm static bed height and a freeboard height of 170 cm. Ammonia gas was injected at 52 cm above the distributor where the temperature is ca. 700° C by an uncooled stainless steel tube injector. Experiments were carried out to investigate the effects of amminia gas injection on sulphur dioxide emissions at unstaged conditions of: (i) excess air level, (ii) NH₃:SO₂ molar ratio, (iii) fluidizing velocity and (iv) bed height.A maximum reduction of 75% in SO₂ emissions was found at 40% excess air, at an NH₃:SO₂ molar ratio of 5.4. The onset of SO₂ reduction occurred at an NH₃:SO₂ ratio of 1.5 However, the most effective ratio was found to be between 3 and 5. Fluidizing velocity and bed height were also found to have significant influence on SO₂ reduction.It is difficult to determine how the SO₂ reduction varied with operating conditions. When ammonia is added in the main combustor zone, the temperature is much higher than that required for the occurrence of sulphur dioxide-ammonia and sulphur trioxide-ammonia reactions. However, this paper points out the significance of ammonia addition in the reduction of sulphur dioxide.     

CO and NO2 pollution in a long two-way traffic road tunnel: investigation of NO2/NOx ratio and modelling of NO2 concentration

The CO, NO and NO2 concentrations, visibility and air flow velocity were measured using continuous analysers in a long Norwegian road tunnel (7.5 km) with traffic in both directions in April 1994 and 1995. The traffic density was monitored at the same time. The NO2 concentration exceeded Norwegian air quality limits for road tunnels 17% of the time in 1994. The traffic through the tunnel decreased from 1994 to 1995, and the mean NO2 concentration was reduced from 0.73 to 0.22 ppm. The ventilation fan control, based on the CO concentration only, was unsatisfactory and the air flow was sometimes low for hours. Models for NO2 concentration based on CO concentration and absolute air flow velocity were developed and tested. The NO2/NOx ratio showed an increase for NOx levels above 2 ppm; a likely explanation for this phenomenon is NO oxidation by O2. Exposure to high NO2 concentrations may represent a health risk for people with respiratory and cardiac diseases. In long road tunnels with two-way traffic, this study indicates that ventilation fan control based on CO concentration should be adjusted for changes in vehicle CO emission and should be supplemented by air flow monitoring to limit the NO2 concentration.     

International CO2 emissions targets and timetables: An analysis of the AOSIS proposal

In this paper, we use a two-region version of the CETA model to analyze international CO₂ emission control policies. The policies we consider are all substantially equivalent to a policy recently proposed by the Alliance of Small Island States (AOSIS). The AOSIS proposal requires the OECD alone to reduce emissions, while the alternatives we consider achieve equivalent reductions via emission rights traded (1) between regions, (2) between time periods, or (3) both. We find that tradeable rights systems provide significant overall cost savings relative to the AOSIS proposal. Cost reductions may be roughly 60% for rights tradeable between regions, 50% for rights tradeable between time periods, and 95% for rights tradeable between regions and time periods. The benefits of these cost reductions accrue to both the OECD and the Rest of the World. Our results underscore the importance of using an efficient policy to achieve any given atmospheric concentration objective.     

Electricity and emission-permits trade as a means of curbing CO2 emissions in the Nordic countries

The four Nordic countries Sweden, Denmark, Finland and Norway have fully integrated electricity grids, implying that electricity trade hitherto has accounted for a crucial part of each country’s power balance. Electricity trade also provides cost-efficient opportunities for the Nordic countries to either jointly or separately fulfil their CO₂ obligations. Assuming the targets that were agreed upon in (the aftermath of) the Kyoto negotiations in 1997, and establishing scenarios where CO₂-emission-permits trade among the Nordic countries is allowed, it is shown that the value of emission trading is somewhat larger than the corresponding value of electricity trade. Furthermore, if both electricity and emission permits can be traded on a common Nordic market this can lead to amplified economic benefits yielding a gain that exceeds the sum of the separate values of electricity and emission permits trade. It is also shown that the additional costs of fulfilling the Kyoto protocol are small compared to the total costs of the Nordic energy system. This revised version was published online in July 2006 with corrections to the Cover Date.     

Prediction models of CO, SPM and SO2 concentrations in the Campo de Gibraltar Region, Spain: a multiple comparison strategy

The 'Campo de Gibraltar' region is a very industrialized area where very few air pollution studies have been carried out. Up to date, no model has been developed in order to predict air pollutant levels in the different towns spread in the region. Carbon monoxide (CO), Sulphur dioxide (SO(2)) and suspended particulate matter (SPM) series have been investigated (years 1999-2000-2001). Multilayer perceptron models (MLPs) with backpropagation learning rule have been used. A resampling strategy with two-fold crossvalidation allowed the statistical comparison of the different models considered in this study. Artificial neural networks (ANN) models were compared with Persistence and ARIMA models and also with models based on standard Multiple Linear Regression (MLR) over test sets with data that had not been used in the training stage. The models based on ANNs showed better capability of generalization than those based on MLR. The designed procedure of random resampling permits an adequate and robust multiple comparison of the tested models. Principal component analysis (PCA) is used to reduce the dimensionality of data and to transform exogenous variables into significant and independent components. Short-term predictions were better than medium-term predictions in the case of CO and SO(2) series. Conversely, medium-term predictions were better in the case of SPM concentrations. The predictions are significantly promising (e.g., d (SPM 24-ahead) = 0.906, d (CO 1-ahead) = 0.891, d (SO2 1-ahead) = 0.851).     

Case studies on summertime measurements of O3, NO2, and SO2 with a DOAS system in an urban semi-industrial region in Athens, Greece

The objective of this study is to analyze the concentrations of SO₂, NO₂, and O₃ measured by a Differential Optical Absorption Spectroscopy (DOAS) system that was operating at the campus of Technological Education Institute of Piraeus during 2008 and 2009 warm periods (July to September) in relation to the prevailing meteorological conditions. The DOAS system was operating in a particularly polluted area of the West part of Attica basin on a continuous basis, measuring the concentration levels of the main pollutants (O₃, NO₂, and SO₂) as well as aromatic hydrocarbon substances (benzene, toluene, and xylene). According to the analysis, the SO₂ concentration levels at this measuring site are rather high and this may be attributed to the characteristics of this measuring site. Proximity of roadways and local circulation are just some of the factors that can affect the concentration levels of monitoring of pollutant concentrations such as NO₂ and surface ozone. The results provide evidence for the occurrence of an atmospheric phenomenon that produces higher ozone concentrations during weekends despite lower concentrations of ozone precursors. This phenomenon is known as the weekend effect.     

Emissions of SO2, NO x and particulates from a pipe manufacturing plant and prediction of impact on air quality

Integrated pipe manufacturing industry is operation intensive and has significant air pollution potential especially when it is equipped with a captive power production facility. Emissions of SO₂, NO _x , and particulate matter (PM) were estimated from the stationary sources in a state-of-the-art pipe manufacturing plant in India. Major air polluting units like blast furnace, ductile iron spun pipe facility, and captive power production facility were selected for stack gas monitoring. Subsequently, ambient air quality modeling was undertaken to predict ground-level concentrations of the selected air pollutants using Industrial Source Complex (ISC 3) model. Emissions of SO₂, NO _x , and particulate matter from the stationary sources in selected facilities ranged from 0.02 to 16.5, 0.03 to 93.3, and 0.09 to 48.3 kg h^???1, respectively. Concentration of SO₂ and NO _x in stack gas of 1,180-kVA (1 KW = 1.25 kVA) diesel generator exceeded the upper safe limits prescribed by the State Pollution Control Board, while concentrations of the same from all other units were within the prescribed limits. Particulate emission was highest from the barrel grinding operation, where grinding of the manufactured pipes is undertaken for giving the final shape. Particulate emission was also high from dedusting operation where coal dust is handled. Air quality modeling indicated that maximum possible ground-level concentration of PM, SO₂, and NO _x were to the tune of 13, 3, and 18 μg/m³, respectively, which are within the prescribed limits for ambient air given by the Central Pollution Control Board.     

Effect of national-level spatial distribution of cities on national transport CO2 emissions

Most research regarding the relationship between cities and transportation carbon emission is focused on intra-city travel, and it has been found that compact patterns tend to emit less carbon. Yet, little is known about the impact of national-level spatial distribution of cities and inter-city transportation on transportation CO₂ emissions. Further, most studies regarding the impact of urbanization on CO₂ emission directly examine the relationship between urbanization rate and CO₂ emission with little consideration of the national spatial pattern of urbanization. This study hypothesizes that the national-level spatial distribution of cities – in a dispersed or polarized pattern – affects national transport CO₂ emissions due to the varying intensity of inter-city transportation. This study uses the Gridded Population of the World v3 and v4 from Socioeconomic Data and Applications Center (SEDAC) of NASA to examine the national-level spatial distribution of urban agglomerations. It applies the Stochastic Impacts by Regression on Population, Affluence, and Technology (STIRPAT) model. The analysis shows that, among 60–90% of urbanized countries, spatially dispersed urbanized countries (e.g., countries with many medium-sized cities scattered over the territory) show a lower national transportation CO₂ emission than spatially polarized urbanized countries (e.g., there are only a few large cities). The urban system elasticity of transportation CO₂ emissions is 0.4 or 0.6. That is, if the degree of polarization decreases by 1%, national transportation CO₂ emissions decrease by approximately 0.4–0.6%. This effect is similar to the effect of GDP per capita of around 0.5%. Because it is particularly difficult to disperse people and economic activities across a country once spatial polarization is set, this study's findings have the most significant implications for urbanizing countries. If urbanizing countries adopt national urban policy and territorial plans to form dispersed cities, it could reduce transportation carbon emissions and promote sustainable development. For already urbanized countries, national urban policy development is recommended to promote spatially dispersed rather than polarized national urban systems.     

A novel wet-scrubbing process using Fe(VI) for simultaneous removal of SO2 and NO

The objective of this work was to develop a novel wet-scrubbing process using Fe(VI) for the simultaneous removal of gaseous NO and SO(2). The oxidation of SO(2) and NO with Fe(VI) was studied in aqueous solution at alkaline pH (9.0-11.0). A stoichiometric molar ratio for NO and SO(2) oxidation with Fe(VI) was determined to be nearly 3.0. Sulfate and nitrate was identified as final products by ion chromatography from the reaction at pH 9.0-11.0. The feasibility of simultaneous removal of multiple gas pollutants with the continuous feeding of ferrate in lab-scale was investigated from the view of industrial application. It was found that the removal efficiency of NO and SO(2) was enhanced with the increase of Fe(VI) concentration, more than 90% NO removal efficiency and 100% SO(2) removal efficiency were achieved by wet-scrubbing process using Fe(VI) at room temperature and ambient atmosphere. The results demonstrate that Fe(VI) could be an effective wet-scrubbing agent for the simultaneous removal of NO and SO(2).     

The environmental Kuznets curve of CO2 emissions in the manufacturing and construction industries: A global empirical analysis

The manufacturing and construction industries have significantly contributed to the increase of carbon dioxide (CO₂) emissions. Environmental Kuznets curve (EKC) hypothesis is widely leveraged to analyze the peak of CO₂ emissions, which is considered as a pivotal step for the effective CO₂ emission reduction in previous studies. This study tests the EKC hypothesis using the data of CO₂ emissions of manufacturing and construction industries from 121 countries throughout 1960–2014, and turning points (TPs) are calculated for the countries where EKC hypothesis is validated. The results show that the EKC hypothesis was validated by 95 out of 121 countries, among which, 13 countries have not reached any of the three TPs, 11 countries have reached the first-step TP (TP_CI), 21 countries have reached the second-step TP (TP_PC), and 50 countries have reached the third-step TP (TP_TC). Moreover, the result of examination of the EKC existence at four income levels indicates the higher-income nations own a higher proportion of countries validates the EKC hypothesis and reach the TP. These findings help policy-makers analyze the TP status quo and generate step-wise strategies for national CO₂ emission reduction of manufacturing and construction industries.