Air pollution at the Bily Kriz mountains in the Czech Republic

An evaluation of air pollution at the Bily Kriz mountains in the Czech Republic is given. Annual daily concentrations of sulphur dioxide (SO₂), nitrogen oxides (NO_x), particulate matter of size 10 mm (PM₁₀) and ozone (O₃) measured in the years 1994–2000 are presented. Air pollution at Bily Kriz is assessed with the reference to the European Union Directives and the standards adopted by the Czech Republic. In general, the concentrations of air pollutants were lower in 1996 for ozone and decreased for SO₂, NO_x and PM₁₀ from 1994. The daily values of SO₂ and PM₁₀ exceeded the European Union limits in approximately 0.0% and 5.5% of cases, respectively. The values of ozone exceeded the limits for the considered period.     

Influence of meteorological factors on air pollution concentration for a coastal region in India

A long-term study of measurement of concentration of NO_x, SO₂ and TSP pollutants have been done in a port and harbour region in India. Monthly measurements of gaseous and particulate pollutants were made at six monitoring stations from January 1997 to December 2000. Meteorological data was also simultaneously collected. In this study, the relationship between monitored ambient air quality data and meteorological factors, such as wind speed, temperature, is statistically analysed, using the SPSS package. The monthly mean concentrations of NO_x, SO₂ and TSP were in the range of 19.5–59.0 μg/m3, 8.6–51.3 μg/m3 and 88.2–199.3 μg/m3, respectively. The results show that TSP is strongly correlated with NO_x and SO₂ with a correlation coefficient of 0.83 and 0.82, respectively. The correlation coefficients for TSP, NO_x, and SO₂ with wind are –0.78, –0.78, and –0.88, respectively.     

Treatment of reactive dyes and textile finishing wastewater using Fenton's oxidation for reuse

Fenton's oxidation (FO) was used to decolourise and degrade some reactive dyes (Remazol Black 5, Remazol Red, Remazol Blue, Remazol Yellow) and raw textile finishing industry effluents (S1, S2, S3) containing mainly reactive dyes. The operational conditions for pH varied between 2.5 and 4.0 while temperature ranged from 30°C to 50°C. The concentrations of FeSO₄ and H₂O₂ varied to a wide range (200–600 mg/l of FeSO₄, 300–1000 mg/l of H₂O₂) depending on the type of the dyes and their mixture and textile additives used in the process. FO is highly effective for colour removal (>99%) for reactive dyes and (87–94%) for textile finishing wastewater. It can be applied as a pretreatment and the remaining total dissolved solids (TDS) can be removed by an additional advanced process, e.g. membrane process.     

Measurement of atmospheric particles and anionic species across central Taiwan

The ambient air concentrations and fluxes of various anionic species were sampled by MOUDI, TSP and dry deposition plates at a traffic sampling site in Taichung, central Taiwan. In the sampling period, from September to December 2000, the ambient air particle concentrations (PM₁, PM_2.5, PM₁₀ and TSP) were lower in the September than in the other three months (October to December). The reason is that the northwest wind brought more particles (diameter less than 10 μm) and the higher wind speed caused higher dry deposition fluxes and TSP concentrations in the last three months. The anion species percentages of TSP were 0.24%, 13.7%, 0.52%, 12.0%, 18.9'% and 54.6% for F^-, Cl^-, Br^-, NO₂^-, NO₃^- and SO₄^2-, respectively. The results revealed that SO₄^2-, NO₃^-, Cl^- and NO₂^- were the dominant species at the traffic sampling site. The ion-size distributions of Cl^-, NO₂^- and NO₃^- were unimodal, the main peak being between 3.2 and 5.6 μm. In contrast, the size distribution of SO₄^2- was bimodal, with the main peaks in the particle size ranges 0.32.0.56 μm and 3.2.5.6 μm. The ambient average particle dry deposition flux was 6.28 μg/m2/s, and the dry deposition fluxes were 0.01, 94.6, 0.05, 34.7, 72.2 and 376.4 ng/m2/s for F^-, Cl^-, Br^-, NO₂^-, NO₃^- and SO₄^2-, respectively. The dry deposition velocities were 3.10, 0.03, 3.67, 0.05, 1.54, 2.03 and 3.67 cm/s for F^-, Cl^-, Br^-, NO₂^-, NO₃^- and SO₄^2-, respectively.     

Monitoring of phytoplankton biomass and nutrients in a polluted stream

The spatial and temporal variations in the concentrations of nutrients (NH₄⁺, NO₂⁻, PO₄³⁻, SiO₄⁻) and chlorophyll a were monitored simultaneously in a slow-flowing watercourse (Saricay Stream, Turkey), which runs in a rural–urban gradient. Chlorophyll a concentrations ranged between 0.044 μg l^-1 and 206.15 μg l^-1 and, in general, the higher concentrations of chlorophyll a and ammonium were measured downstream of the raw sewage outfalls. Nitrate was by far the most abundant form of inorganic nitrogen, and its concentration ranged between 411.71 μM and 87.25 μM. Silicates and phosphates were always potentially limiting to biomass relative to nitrogen. Agricultural run-off and point discharges from urban sources greatly affected the chemical composition of the water in the Saricay Stream and drove the system towards eutrophication.     

Flow-rate and pollution characteristics of domestic wastewater

The characteristics of the flow-rate and pollution parameters of the domestic wastewater of a medium-size city (Sivas, Turkey) have been investigated. The design and the operating parameters of a wastewater treatment plant appropriate to such a settlement were also studied. Daily and monthly flow-rate measurements and wastewater samples were taken at the outlet. Peak values of the flow-rate were observed between the hours 09:00 and 14:00. Domestic wastewater production per capita was determined as 170.6 litres per day. The wastewater biological reaction ratio coefficient (k), the BOD₅/COD ratio and the BOD₅/N ratio varied in the ranges 0.113–0.312, 0.44–0.67 and 3.1–9.5 per day, respectively. Daily pollution load parameters per capita were determined as follows: 47.3 g for BOD₅, 85.3 g for COD, 34.9 g for suspended solids, 7.9 g for nitrogen and 1.32 g for phosphorus.     

Roadside particulate levels at 30 locations in the Kathmandu Valley, Nepal

Roadside particulate levels (PM₁₀) at 30 locations throughout the Kathmandu Valley, Nepal are reported. There were seven sampling cycles from January to December 1999. PM₁₀ levels ranged between 1000 and 6000 μ/m3 for 1-h sampling. There was no consistent trend in PM10 levels with respect to monitoring cycle, average precipitation or wind speed. There is no WHO guideline for PM₁₀ (no safe exposure threshold), but the EPA 24-h standard is 150 μ/m3. The major sources of roadside PM₁₀ include dust re-suspension from vehicular movement and human activity, and particulate emissions from old vehicles. Other sources of PM₁₀ in the valley include cement and brick factories. Studies are currently being conducted to determine the lead content of PM₁₀ from roadside samples. Additional studies are warranted to assess the potential adverse human health effects of acute or chronic exposure to high particulate levels reported in this study.     

Sensitivity analysis of the CERES-wheat model for variations in CO2 and meteorological factors in Northwest Turkey

Plant growth is very sensitive to variations in atmospheric factors. Possible effects of climate change on plant growth can be estimated and evaluated using the crop growth simulation models. In this study, the CERES (Crop Environment Resource Synthesis)-wheat model was applied to two consequent growing seasons (1997–1998 and 1998–1999) in order to determine the model sensitivity on the changes in several meteorological factors such as air temperature, precipitation, solar radiation and carbon dioxide (CO₂) concentration. In the model, the air temperature variations were applied from ±1°C up to ±2°C and CO₂ were changed in the range of 20% to 100%, while the solar radiation, precipitation were varied between 10% and 20%. Biomass and the grain yield of the wheat crop were influenced positively by the increased combination of the solar radiation, air temperature and CO₂. However, low crop responses to the variations in precipitation were unexpected.     

Source contribution of atmospheric aerosols in Bangkok metropolitan area by CMB8 receptor model

The CMB₈ model was applied for source apportionment of particulate matter in Bangkok area. The 24 h of ambient data were collected and analysed for elemental composition during December 1996 to January 1997 by high volume air samplers at a station in Bangkok, Thailand. Seven source profiles and the average mass concentrations of 42 ambient data were used to run the chemical mass balance (CMB₈) model. The source apportionment by CMB₈ gave similar results comparing with factor analysis – multiple regression (FA–MR) model of the same data. The results revealed that major sources of particulate matter in Bangkok were: soil (33%), road dust (33%) and automobile (15%). The minor source contributions were: sea salt (4.34%), refuse incineration and biomass burning (0.84%), steel mill (0.62%) and fuel oil combustion (0.35%). The lack of source profile for biomass or open burning in Bangkok resulted in much lower predicted contribution of this source when compared to that from FA–MR. When apply this CMB₈ model with daily ambient data, the result revealed that one fourth of daily CMB₈ source apportionment had high value of ² (>4). These exceedance values of Chi² also point out that one of the selected sources (biomass burning) may not be the true contributing sources. Presumably, accurate biomass burning source profile is needed to improve the CMB calculation of source contributions for particulate matter in Bangkok metropolitan area.     

Study of the weekday-weekend variation of air pollutants in a typical Mediterranean coastal town

A study of the air pollution in the Greek coastal town Volos was performed using the available data of the last ten years. Quantile analysis showed that ozone concentrations during weekends were higher by 5–10% in comparison to those on weekdays, while the inverse was observed for the other pollutants, indicating the occurrence of the so called 'weekend effect'. Analysis of the maximum values of the high ozone period showed even higher differences. The pollutants NO, NO₂, CO, and SO₂ were lower during weekends compared to weekdays, by about 30%, 20%, 25% and 10% respectively.     

Time-resolved ammonia measurement in vehicle exhaust

The objective of this study was to identify the influence of sampling and analytical approach on the quality of NH3 emission data of a gasoline-fuelled three-way catalyst vehicle. NH₃ concentration measurements have been performed in the tailpipe and in the diluted exhaust after a constant volume sampling (CVS) system during five different test cycles. Chemical ionisation mass spectrometry (CI-MS) and Fourier transform infrared spectroscopy (FTIR) were used to acquire ammonia concentrations in real-time. Independently, NH₃ emission rates were determined by continuous absorption of a flow-proportional sample of exhaust gas in diluted sulphuric acid and subsequent ion chromatography (IC). Ammonia emission rates ranged from 22–94 mg km^-1. The results of the three compared techniques are in good agreement. Furthermore, time-resolved ammonia emission profiles recorded by CI-MS and FTIR coincided with respect to emission levels as well as emission dynamics. However, in the dilution tunnel, severe ammonia adsorption was observed leading to long lasting memory effects or even analyte loss. Therefore, neither ammonia real-time emission data nor NH₃ emission rates should be acquired after a CVS system.     

Air pollution modelling of the Calabrian pine forests withered by the Yatagan thermal power plant, Turkey

The emissions from the chimney of the Yatagan thermal power plant have caused a 3050-hectare forest to wither. Such air pollutants as sulfur dioxide, nitrogen oxides and fly ash are carried towards the Bencikdagi Calabrian pine forests on the prevailing north-east winds. To study these effects, the Q-Basic computer program developed for the Gaussian puff model was used with meteorological data provided by the Yatagan Meteorological Office and the pollutant loads formed by the thermal power plant. In the grid system on the map showing the surroundings of the thermal power plant, the concentrations of the pollutants in each grid square were determined. The Yatagan plant has three units containing 9000 mg/m3 sulfur dioxide, 1800 mg/m3 nitrogen oxides and 680 mg/m3 fly ash in its chimneys. The minimum pollutant emissions were found to be 100 μg/m3 SO₂, 20 μg/m3 NO_x2, and 77 μg/m3 NO_x     

Trends in air quality and population exposure in Santiago, Chile, 1989–2001

This study focused on establishing trends in the period 1988–2001 in PM_2.5, PM₁₀ and ozone concentrations in Santiago, Chile, and linking those to population exposure. There is strong seasonality in the concentration levels, driven by prevailing meteorological conditions, with the concentration of particulates peaking at the beginning of winter, whereas the ozone concentration is highest during the summer. The levels of PM_2.5 and PM₁₀ have substantially decreased since the late 1980s and so has the population exposure. Nevertheless, the majority of the population is still exposed to annual average levels that are above standard values. The situation with ozone exposure is different; no substantial decrease can be observed in the data. If anything, certain parts of Santiago, notably the south-east, have shown increased levels of ozone. Overall population exposure indicates that the average person was more at risk of ozone in the year 2000 than they were in 1993.     

VOC composition and ozone-forming potential of the exhaust gas of in-use motorcycles

The emission profile of volatile organic compounds (VOC) and the ozone-forming potential (OP) of the exhaust gas of six in-use motorcycles (four 4-stroke- and two 2-stroke-engines) were determined. The motorcycles were tested on a chassis dynamometer in a real-world driving cycle. The analysis involved the C2–C12-hydrocarbons as well as the aldehydes and ketones. Additionally, the regulated THC and NO_x emissions were measured according to the test procedure for type approval (ECE 40). Two vehicles did not fulfil the THC emission standard, whereas all vehicles met the requirements for NO_x emission. The aromatic fuel components toluene and xylene, and the combustion products ethene and propene contributed most to the OP of the VOC emission. The highest OP was found with the 2-stroke engines. The VOC profile of the emissions varied with vehicle and driving conditions. The reactivity of the exhaust gas, defined as gram ozone per gram of non-methane organic gases (NMOG), increased with vehicle speed.     

Characteristic study of particulates and metallic elements at an urban sampling site in Taichung, central Taiwan

Atmospheric total suspended particulate concentrations and metallic element concentrations were measured at three locations, characteristic of urban, suburban and rural sites. The sampling period was from July 2000 to August 2000. The results indicated that the urban sampling site had the highest total suspended particulate concentrations (average 108.61μ1m3), followed by the suburban site (average 60.11μ1m3) and the rural site (average 53.31μ1m3). The average PM_2.5 concentrations (24.11μ1m3) were higher than the PM_2.5-10 concentrations (12.81μ1m3) at the urban site. The average distributed ratios for PM_2.5/PM_2.5-10 were about 1.29, 1.53, 0.12, 1.12 and 2.31 for Pb, Zn, Fe, Ni and Cr, respectively. The average total suspended particulate mass ratios for daytime and nighttime were about 1.72. As for the elements Cu, Pb, Zn, Fe, Ni and Cr, these ratios were about 0.63, 0.97, 0.54, 1.66, 0.53 and 1.12, respectively. The total suspended particulate daytime concentrations of Pb and Zn were positively correlated (R = 0.925) at the urban sampling site. The elements Ni and Cr were positively correlated both during the daytime (R = 0.648) and the nighttime (R = 0.511), revealing that they came from the same emission source during daytime and nighttime, at the urban sampling site.     

Assessment of particulates in the urban atmosphere of Sao Carlos, Brazil

A survey on the concentration of particulate matter in the urban atmosphere was carried out in the city of Sao Carlos, Brazil. Five sites were selected for data collection one in the city centre (high concentration of people and automotive vehicles), three in industrial areas, and one at the interface with the countryside. The particle size distribution and mass concentration, temperature, humidity and wind velocity were measured at each site. In the city centre, the concentration of the particles smaller than 10 μm (PM₁₀) was also measured. The particle size distribution was obtained with a laser scattering particle counter. The total and PM₁₀ concentrations were obtained with high volume samplers. The tests were performed for 75 consecutive weeks. The results show that the particle concentration is sensitive to seasonal conditions. During autumn and winter, which is the drier and windy period of the year, larger particles were dispersed, leading to higher concentrations, both total and PM₁₀. The relative humidity varied with the schedule of sampling and with the season the autumn and winter weeks were much drier than the other periods. Higher rainfall levels coincided with lower particle concentrations. All these results are statistically significant.     

Evaluation of air pollution trends in Istanbul

Previously, SO2 = SO₂ and PM₁₀ (particulate matter less than 10 Bm in size) concentration distributions have been investigated in order to assess air pollution in Istanbul during the winter season (November–March) in which the concentration of these pollutants had reached formidably high levels due to the consumption of low-quality fuels (mainly coal) for residential heating. In this study, the effect of the increased share of natural gas and high-quality coal consumption in residential areas on air pollution levels was investigated. Modelling employing the method of kriging by spherical interpolation was used to obtain the concentration distribution of these pollutants, and spatial distributions of concentrations were generated. The pollution map obtained by this method indicated that increased usage of natural gas and high-quality coal in residential areas significantly improved air quality.     

Metallic elements in particulates released during incense-burning at Tzu Yun Yen temple, Taichung, Taiwan

Concentrations of ambient suspended particulates were measured at Tzu Yun Yen temple (120°, 34′ 10”E; 24°, 16′, 12”N), using a Universal sampler and dry deposition plates. The temple is a characteristic incense-burning and semi-open sampling site. PM_2.5 concentrations for Period 1 (average 901μg/m3) were higher than those for Period 2 (average 701μg/m3). Results for average PM_2.5-10concentrations showed equal distributions in Period 1 and Period 2. Average ratios of PM_2.5/ PM₁₀ were higher in Period 1 (74%) than Period 2 (71%). In addition, the suspended particulate (PM₁₀) elements concentrations during Zhong Yuan Jie, and the first and 15th days of nong li for each month (Chinese lunar calendar) were all higher than during non-Zhong Yuan Jie and non-first and non-15th days. Furthermore, the dry deposition velocities of manganese in fine particulates (PM_2.5) and suspended particulates (PM₁₀) were 1.43 and 0.751cm/s, respectively, and the dry deposition velocities of cadmium in fine particulates (PM_2.5) and suspended particulates (PM₁₀) were 1.86 and 0.991cm/s, respectively.     

Short-term prediction of means of artificial neural urban NO2 pollution by networks

A neural network model for the short-term prediction of concentrations of urban pollutants was developed and applied to the Turin (Northern Italy) air quality network. In particular, the study was focused on NO₂ concentrations measured at five stations; t + 3 and t + 24 hour NO₂ concentration forecasting based on hourly meteorological and concentration data gave good agreement with observed concentrations. This is particularly true for the mean concentration values and concentration distribution. The time of occurrence of peak values was correctly forecast but the amounts were generally underestimated. To reduce this underestimation, an empirical step function was applied in the t + 24 case. This allowed an accurate estimate to be obtained of the few cases in which 50% of the air quality monitoring stations exceeded the attention level (200 μg m^-3) during the following day for at least one hour.     

Photochemical air pollutant levels and ozone phytotoxicity in the region of Mesogia–Attica, Greece

The levels of photochemical air pollutants: O₃, NO and NO₂, were monitored in Athens and in the neighbouring region of the Mesogia plain (Spata, Artemis and Markopoulo) from 1 May–31 August 2000. Phytodetection of ozone was also conducted using bioindicator plants of Bel-W3 and Zichnomirodata (KK6/5) tobacco varieties. The average maximum daily O3 concentration was 60–75 ppb, while the 24 hour average ranged from 40–65 ppb. The AOT40 (ppb hours) index was very high in Athens (16 679 over 121 days), Spata (16 325 over 110 days), Artemis (8093 over 22 days) and Markopoulo (18 646 over 113 days), suggesting potentially phytotoxic ozone levels. The ozone bioindicator plants of Bel-W3 and KK6/5 tobacco varieties were highly injured in all regions confirming the phytotoxicity of those ozone levels. The levels of NO and NO₂ recorded at the three stations, in the Mesogia plain, were considerably lower than those occurring in Athens. The data presented here provide important background information concerning pollution levels in the Mesogia plain shortly before the operation of the new international airport 'Eleftherios Venizelos' in this region (March 2001).