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1.
Kim KH Choi YJ Oh SI Sa JH Jeon EC Koo YS 《Environmental monitoring and assessment》2006,121(1-3):341-352
In order to explore the environmental behavior of reduced sulfur compounds (RSC) as malodorous components emitted from diverse source processes, the distribution characteristics of four sulfur (S) compounds - hydrogen sulfide (H2S), methyl mercaptan (CH3SH), dimethyl sulfide (DMS: (CH3)2S), and dimethyl disulfide (DMDS: (CH3)2S2) – were investigated in a municipal landfill area. In the course of this study, their ambient concentration levels were measured during two time periods from 13 individual spots selected as a function of distance from the center of the landfill site. The results generally indicated the absolute dominance of H2S over the other S compounds investigated (up to 5 km radius) such that their mean values were found as 1415 (H2S), 148 (DMS), 20.6 (CH3SH), and 14.4 ppt (DMDS). When our data were compared in terms of either varying distance from the source or relationship with meteorological conditions, the H2S data sets were most evident to reflect the potential effects of strong source processes in the landfill environment, relative to other S gases (or to volatile organic compounds measured concurrently). The results of this study further indicated the relatively good correspondence between the measured H2S concentration level and humans' intuitive sensory of odor and nuisance. 相似文献
2.
Pal R Kim KH Jeon EC Song SK Shon ZH Park SY Lee KH Hwang SJ Oh JM Koo YS 《Environmental monitoring and assessment》2009,148(1-4):109-125
The atmospheric concentrations of several reduced sulfur compounds (RSCs) including H(2)S, CH(3)SH, DMS, CS(2), and DMDS were measured concurrently from a series of field campaigns covering multiple locations in the surroundings of a large industrial region (August 2004 to September 2005). These field studies have been designed and undertaken to inspect the concentrations of RSCs in ambient air. The RSC concentrations were found to occur in a highly variable range. H(2)S (1.06 +/- 2.07 ppb) was found to be the most abundant RSC followed by CS(2) (0.84 +/- 0.54 ppb), DMDS (0.36 +/- 1.21 ppb), DMS (0.24 +/- 0.83 ppb), and CH(3)SH (0.11 +/- 0.23 ppb). The RSC levels measured at the study area were comparable to those observed previously from other polluted environmental settings. When these RSC data were examined further in terms of spatial (industrial vs. non-industrial sites) and seasonal (summer vs. winter seasons) grouping schemes, differences in their concentration levels were statistically insignificant in most cases. In contrast, there were fairly strong variations in temporal patterns over a diurnal cycle. If these RSC concentration data were converted to diagnose the malodor strengths, their effects were in most cases insignificant with minor contribution towards odor nuisances. 相似文献
3.
Yan K. Lau 《Environmental monitoring and assessment》1989,13(1):69-74
A gas chromatograph with a flame photometric detector is set up for the direct analysis of COS, H2S, CS2, SO2, CH3SH, C2H5SH in ambient air.Logarithmic transformation is used to counterbalance the non-linear nature of the detector response for the individual sulphur gases. A quality assurance procedure is described to compensate any variation of response during field measurement. The use of Tedlar bags for sampling COS, CS2, CH3SH, C2H5SH is acceptable despite the general conception that sulphur gases are unstable in Tedlar bags. 相似文献
4.
Characteristics of malodor pollutants and aromatic VOCs around an urban valley in Korea 总被引:2,自引:0,他引:2
Song SK Shon ZH Kim YK Kim CH Yoo SY Park SH 《Environmental monitoring and assessment》2009,157(1-4):259-275
In this study, the environmental behavior of malodor pollutants (MPs) [including reduced sulfur compounds (RSCs)] and aromatic volatile organic compounds (AVOCs) were investigated around urban valley areas during several field campaigns (February through December 2006). The MPs measured in the study area include the RSCs (H(2)S, CH(3)SH, DMS, and DMDS), ammonia (NH(3)), and styrene (STY); the AVOCs include benzene (BEN), toluene (TOL), ethylbenzene (EB), m,p-xylene (MPX), and o-xylene (OX). The variation of most MP concentrations (except for DMDS) was found to be larger than that of AVOCs. It was found that STY (2,346 +/- 4,867 ppbv) was the most dominant MP followed by NH(3) (447 +/- 285), CH(3)SH (16 +/- 41), and the others (<8). The magnitude of AVOCs was found in the following descending order: TOL (1.4 +/- 2.2 ppbv), EB (1.0 +/- 2.1), MPX (0.9 +/- 2.0), and the others (<0.8). The concentration levels of most MPs on industrial (I) and downwind (D) sites were up to an order of magnitude higher than those at non-industrial (N) and upwind (U) sites. For most AVOCs, the former was ~3 times higher than the latter. For malodor intensity in RSCs, CH(3)SH was the dominant contributor. The concentration difference in target compounds between the sites/periods is likely to be caused by the combined effects such as emission sources, geographical features (e.g., semi-closed topography), and meteorological conditions (e.g., wind directions) in and outside the urban valley. 相似文献
5.
Catalan L Liang V Johnson A Jia C O'Connor B Walton C 《Environmental monitoring and assessment》2009,156(1-4):37-49
Emissions of reduced sulphur compounds (RSCs) from the primary and secondary clarifiers at a Kraft mill were measured for respectively 8 and 22 days using a floating flux chamber. In the primary clarifier, dimethyl disulphide (DMDS) had the highest mean flux (0.83 microg s(-1) m(-2)) among all RSCs, and the mean flux of total reduced sulphur (TRS) was 1.53 microg s(-1) m(-2). At the secondary clarifier, dimethyl sulphide (DMS) had the highest mean flux (0.024 microg s(-1) m(-2)), and the mean flux of total reduced sulphur (TRS) was 0.025 microg s(-1) m(-2). Large variations in fluxes as a function of sampling date were observed in both clarifiers. Emission fluxes of DMS from the secondary clarifier were correlated with temperature in the flux chamber and with the biological and chemical oxygen demands (BOD and COD) of the wastewater. Emission rates of RSCs from the clarifiers were found to be insignificant by comparison with other mill sources. 相似文献
6.
Manual closed chamber methods are widely used for CH4 measurement from rice paddies. Despite diurnal and seasonal variations in CH4 emissions, fixed sampling times, usually during the day, are used. Here, we monitored CH4 emission from rice paddies for one complete rice-growing season. Daytime CH4 emission increased from 0800 h, and maximal emission was observed at 1200 h. Daily averaged CH4 flux increased during plant growth or fertilizer application and decreased upon drainage of plants. CH4 measurement results were linearly interpolated and matched with the daily averaged CH4 emission calculated from the measured results. The time when daily averaged emission and the interpolated CH4 curve coincided during the daytime was largely invariant within each of the five distinctive periods. One-hourly sampling during each of these five periods was utilized to estimate the emission during each period, and we found that five one-hourly samples during the season accurately reflected the CH4 emission calculated based on all 136 hourly samples. This new sampling scheme is simple and more efficient than current sampling practices. Previously reported sampling schemes yielded estimates 9 to 32% higher than the measured CH4 emission, while our suggested scheme yielded an estimate that was only 5% different from that based on all 136-h samples. The sampling scheme proposed in this study can be used in rice paddy fields in Korea and extended worldwide to countries that use similar farming practices. This sampling scheme will help in producing more accurate global methane budget from rice paddy fields. 相似文献
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9.
Recep Kulcu Kamil Ekinci Fatih Evrendilek Can Ertekin 《Environmental monitoring and assessment》2010,167(1-4):545-558
This study quantified spatiotemporal patterns of CH4 and N2O emissions from livestock and poultry production in Turkey between 1961 and 2007. CH4(enteric) (from enteric fermentation), CH4(manure) (from manure management), and N2O(AWM) (from animal waste management) emissions in Turkey were estimated at 1,164, 216, and 55 Gg in 1961 and decreased to 844, 187, and 39 Gg in 2007, contributing a share of roughly 2% to the global livestock-related CH4 emissions and %1.5 to the global N2O(AWM) emissions, respectively. Total CO2-eq emissions were estimated at 50.7 Tg in 1961 and declined from a maximum value of 60.7 Tg in 1982 to a minimum value of 34.5 Tg in 2003, with a mean emission rate of 48 Tg year???1 due to a significant reduction in the number of ruminant livestock. The highest mean share of emissions belonged to West Black Sea (14% and 16%) for CH4(enteric) and CH4(manure) and to North East Anatolia (12% and %13) for N2O(AWM) and total CO2-eq emissions, respectively. The highest emission density was 1.7 Mg km???2 year???1 for CH4(enteric), 0.3 Mg km???2 year???1 for CH4(manure), and 0.07 Mg km???2 year???1 for the total CO2-eq emissions in the West and North East Anatolia regions and 0.09 Mg km???2 year???1 for N2O(AWM) in the East Marmara region. Temporal and spatial variations in CH4(enteric), CH4(manure), and N2O(AWM) emissions in Turkey were estimated using regression models and ordinary kriging at a 500-m resolution, respectively. 相似文献
10.
Diurnal variation of methane emissions from an alpine wetland on the eastern edge of Qinghai-Tibetan Plateau 总被引:1,自引:0,他引:1
Huai Chen Ning Wu Shouping Yao Yongheng Gao Yanfen Wang Jianqing Tian Xingzhong Yuan 《Environmental monitoring and assessment》2010,164(1-4):21-28
Alpine wetland is a source for CH4, but little is known about methane emission from such wetland, especially about its diurnal pattern. In this study we tried to probe the diurnal variation in methane emission from alpine wetland vegetation. The average methane emission rate was 9.6 ± 3.4 mg CH4 m???2 h???1. There was an apparent diurnal variation pattern in methane emission with one minor peak at 06:00 and a major one at 15:00. The sunrise peak was consistent with a two-way transport mechanism for plants (convective at daytime and diffusive at night-time). CH4 emission was found significantly correlated with redox potentials. The afternoon peak could not be explained by diurnal variation in soil temperature, but could be attributable to changes in CH4 oxidation and production driven by plant gas transport mechanism. The results have important implications for sampling and scaling strategies for estimating methane emission from alpine wetlands. 相似文献
11.
Empirical gas emission and oxidation measurement at cover soil of dumping site: example from Malaysia 总被引:1,自引:0,他引:1
Mohammed F. M. Abushammala Noor Ezlin Ahmad Basri Hassan Basri Abdul Amir H. Kadhum Ahmed Hussein El-Shafie 《Environmental monitoring and assessment》2013,185(6):4919-4932
Methane (CH4) is one of the most relevant greenhouse gases and it has a global warming potential 25 times greater than that of carbon dioxide (CO2), risking human health and the environment. Microbial CH4 oxidation in landfill cover soils may constitute a means of controlling CH4 emissions. The study was intended to quantify CH4 and CO2 emissions rates at the Sungai Sedu open dumping landfill during the dry season, characterize their spatial and temporal variations, and measure the CH4 oxidation associated with the landfill cover soil using a homemade static flux chamber. Concentrations of the gases were analyzed by a Micro-GC CP-4900. Two methods, kriging values and inverse distance weighting (IDW), were found almost identical. The findings of the proposed method show that the ratio of CH4 to CO2 emissions was 25.4 %, indicating higher CO2 emissions than CH4 emissions. Also, the average CH4 oxidation in the landfill cover soil was 52.5 %. The CH4 and CO2 emissions did not show fixed-pattern temporal variation based on daytime measurements. Statistically, a negative relationship was found between CH4 emissions and oxidation (R 2?=?0.46). It can be concluded that the variation in the CH4 oxidation was mainly attributed to the properties of the landfill cover soil. 相似文献
12.
Khaparde VV 《Environmental monitoring and assessment》2006,116(1-3):217-231
A workshop on analytical quality control (AQC) of ambient air quality measurement methods for nitrogen dioxide (NO2) and sulphur dioxide (SO2) was conducted by Central Pollution Control Board (CPCB) for officials involved in National Ambient Air Quality Monitoring
(NAAQM) in India. Concentrations of NO2 and SO2 were generated by dynamic dilution system under laboratory conditions at low and high levels and measured using static dilution
system and wet chemical methods laid down by CPCB under section 16(2)(h) of the air act 1981. CPCB provided the measured values
as reference values for comparing the means obtained by the officials participated from thirteen organizations. A tolerance
limit of ±15% of the reference values was specified to accept the results. Generated concentrations, which were unknown to
the participants, were measured using gaseous sampling assembly (Envirotech APM 411, New Delhi, India), and wet chemical methods
laid down by CPCB i.e. the same methodology which is used by the organizations to generate the data of NO2 and SO2 in ambient air. Simultaneously, concentrations were checked by CPCB using automatic analyzers as a check on reference concentration.
It is observed that results of automatic analyzers for NO2 and SO2 were within a tolerance of ±5% with %RSD below 3. On the other hand, results of most of the participants showed variability
in the measurements with %RSD ranging between ±0.8 and ±88.6 and exceedences of means from the tolerance limit with bias ranging
between 1.4 and −59%. To check the cause of high variability in the measurements obtained under identical conditions, duplicate
sampling was performed by one of the participants for SO2 at low concentration level. In this study, results of wet chemical methods, automatic analyzers and results of duplicate
sampling are analysed statistically to assess the cause of high variability in the measurements. Analysis of t-test and analysis of variance (ANOVA) showed highly significant results for NO2 and SO2 at high concentration levels (α 0.05) and for SO2 at both the levels (α 0.01) respectively indicating some bias is existing either in the sampling or in analytical technique.
Duplicate sampling performed to check precision in parallel measurements showed high %RSD indicating the presence of systematic
error in sampling technique as the same calibration factor (CF) was used to measure the concentration of duplicate samples.
Statistical analysis of flow rates of duplicate sampling showed that the sampling assembly could not maintain the constant
flow rate within the ±10% with that measured at the start of the sampling. This resulted in high %RSD and deviation from the
reference values for the results of most of the participants, even after accepting ±15% tolerance limit. There is a need to
improve and evaluate this gaseous sample collection device under laboratory conditions to generate reliable database of NO2 and SO2 in ambient air. 相似文献
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14.
Methane fluxes in aerobic soils 总被引:9,自引:0,他引:9
K. W. T. Goulding T. W. Willison C. P. Webster D. S. Powlson 《Environmental monitoring and assessment》1996,42(1-2):175-187
Aerobic soils are an important sink for methane (CH4), contributing up to 15% of global CH4 destruction. However, the sink strength is significantly affected by land management, nitrogen (N) fertilizers and acidity. The rates of uptake from the atmosphere of both enhanced (10 ppmv) and ambient (2 ppmv) concentrations of CH4 were measured in laboratory incubations of soil cores under controlled conditions taken from sites in the U.K. and Germany. The most rapid rates of uptake were measured in soil from deciduous woodland at pH 4 (measured in water). Extended (150 years) cultivation of land for arable crops reduced uptake rate by 85% compared to that in the same soil under an adjacent woodland. The long-term application of ammonium (NH4)-based fertilizer, but not nitrate (NO3)-based fertilizer, completely inhibited CH4 uptake, but the application for the same period of farmyard manure (FYM) that contained more N than the fertilizer had no inhibitory effect. Where a combination of FYM and inorganic fertilizer was applied there was a reduction in methane uptake rate compared to plots receiving solely FYM.Autoclaving showed that the uptake of CH4 was microbially mediated. The most likely causes of the inhibitory effects seen are (i) insufficient concentrations of CH4
in situ to activate methane monooxygenase; (ii) the direct inhibition of CH4 oxidation by NH
inf4
sup+
ions; (iii) the suppression of methanotrophs by NH4-based fertilizers; (iv) the requirement of methanotrophs for a stable soil architecture which is incompatible with the disturbance caused by regular arable cultivation. 相似文献
15.
B. C. Nguyen J. P. Putaud N. Mihalopoulos B. Bonsang C. Doan 《Environmental monitoring and assessment》1994,31(1-2):131-137
Atmospheric samples collected during rice straw burning at four different locations in Viet-Nam during the dry (March 1992, February 1993) and wet season (August 1992) were analysed for CO2, CO, and CH4. The emission ratios relative to CO2 for CO and CH4 for rice straw burning during the dry season were comparable to those observed on samples collected during burning of savanna in Africa or forest in the USA. During the wet season, however the emission ratios for CO and CH4 relative to CO2 were 3 to 10 times higher. With these emission ratios and estimates of rice production from Southeastern Asia, we estimated that burning of rice straw emits annually about 2.2 Tmol of CO (26 TgC) and 0.2 Tmol of CH4 (2.4 TgC) to the atmosphere. Taking into account these new results, CO and CH4 fluxes from biomass burning could be reevaluated by 5–21% and 5–24%, respectively, in respect with previous estimates of these gas emissions from all biomass burning activities. 相似文献
16.
Marand A Dahlin J Karlsson D Skarping G Dalene M 《Journal of environmental monitoring : JEM》2004,6(7):606-614
A method for determination of technical grade isocyanates used in the production of polyurethane (PUR) is presented. The isocyanates in technical grade products were characterised as di-n-butylamine (DBA) derivatives using LC-MS and LC-chemiluminescent nitrogen detection (CLND) and the total isocyanate content was compared to a titration assay. For collection of isocyanates in air, an impinger-filter sampling technique with DBA as derivatisation reagent was used. Characterised DBA and nonadeuterium labelled DBA derivatives of isocyanates in technical products were used as calibration standards and internal standards, respectively, in the analysis of air samples. Three workplaces were studied where PUR products were produced either by spraying or by moulding. In both technical products and in air samples, a number of monomeric, oligomeric and prepolymeric isocyanates of e.g. methylenebisphenyl diisocyanate (MDI) and hexamethylene diisocyanate (HDI) were characterised. Several of these have not previously been described in workplace atmospheres. In the technical isocyanate products, between 69 and 102% of the NCO content determined by titration was accounted for by LC-CLND. Quantifications of a wide range of isocyanates in air samples were performed with correlation coefficients in the range 0.988-0.999 (n= 8) and the instrumental detection limits were 0.7-25 pg. At the two workplaces where MDI- and HDI isocyanurate-based products were sprayed, the isocyanate composition in the air reflected the composition in the technical product. At the workplace where a MDI-based product was used in a moulding process, only the monomeric isocyanates were found in the air. The advantage of using characterised technical grade isocyanates as analytical standards was clearly demonstrated and the possibility of using index compounds when monitoring isocyanate exposure is discussed. 相似文献
17.
Mohammed F. M. Abushammala Noor Ezlin Ahmad Basri Rahmah Elfithri 《Environmental monitoring and assessment》2013,185(12):9967-9978
Methane (CH4) emissions and oxidation were measured at the Air Hitam sanitary landfill in Malaysia and were modeled using the Intergovernmental Panel on Climate Change waste model to estimate the CH4 generation rate constant, k. The emissions were measured at several locations using a fabricated static flux chamber. A combination of gas concentrations in soil profiles and surface CH4 and carbon dioxide (CO2) emissions at four monitoring locations were used to estimate the CH4 oxidation capacity. The temporal variations in CH4 and CO2 emissions were also investigated in this study. Geospatial means using point kriging and inverse distance weight (IDW), as well as arithmetic and geometric means, were used to estimate total CH4 emissions. The point kriging, IDW, and arithmetic means were almost identical and were two times higher than the geometric mean. The CH4 emission geospatial means estimated using the kriging and IDW methods were 30.81 and 30.49 g m?2 day?1, respectively. The total CH4 emissions from the studied area were 53.8 kg day?1. The mean of the CH4 oxidation capacity was 27.5 %. The estimated value of k is 0.138 year?1. Special consideration must be given to the CH4 oxidation in the wet tropical climate for enhancing CH4 emission reduction. 相似文献
18.
M. Luisa Sánchez M. Ángeles García Isidro A. Pérez Nuria Pardo 《Environmental monitoring and assessment》2014,186(5):2823-2834
Continuous methane, CH4, concentrations were measured in a rural area of the upper Spanish plateau from June 2010 to May 2012 by cavity ring-down spectroscopy technique. The results obtained have proven the local impact of anthropogenic nearby sources on CH4 concentrations, and evidence a significant influence on the overall mean, averaged daily and seasonal patterns recorded at the measuring site. The positive anomalies in CH4 concentrations, statistically significant at 95 %, in the southeast sector, defined here as ESE, SE, SSE and S sectors, have been attributed to the contribution of the Valladolid urban plume and the urban landfill. Based on this finding, CH4 background levels were associated to the concentrations recorded in the remaining un-disturbed sectors. CH4 means of the overall data set, the southeast sector and background sectors yielded average means of 1,894.1, 1,927.9 and 1,887.1 ppb, respectively. The diurnal and seasonal patterns of the overall data set and background concentrations have shown that CH4 concentrations are mainly dominated by its reaction with OH radicals. Maximum hourly concentrations were reached during night-time and early morning, 5–7 h, whereas minimum concentrations were recorded at 16 h. Maximum and minimum monthly means were recorded in January and July, respectively. The diurnal and seasonal amplitudes, namely, peak-to-peak means, of background concentrations were 25.1 and 48.1 ppb, respectively. These values were significantly lower than those obtained for the overall data set, 42.9 and 58.1 ppb, revealing the significant role of local influences on CH4 concentrations despite the low frequency of southeast winds recorded at the measuring site, 16.9 %. 相似文献
19.
The anthropogenic emission sources of methane (CH4) and nitrous oxide (N2O) in the Federal Republic of Germany were investigated. The object of the recently completed first phase of this research project was to summarize the present knowledge about the emission sources, make a first rough estimate of the emissions, identify the need for further research in the field, and - as far as possible - discuss the existing possibilities to reduce emissions. The main CH4 emission sources identified are the landfills, stock farming and pit mining, the main N2O sources are agriculture (including a minor contribution from animal wastes) and the production of adipic acid, the latter possibly being reducible by means of a new catalytic process. The total anthropogenic emissions of CH4 from Germany are estimated at 5.4 – 7.7 million tonnes per year, contributing a share of roughly 2 % to the world-wide anthropogenic emissions (350 million t/a). Those of N2O are estimated at 200 000 – 280 000 tonnes per year (world-wide 1.4 – 6.5 million t/a). 相似文献
20.
Santosh Ranjan Mohanty Parul Rajput Bharati Kollah Dipanti Chourasiya Archana Tiwari Muneshwar Singh A Subba Rao 《Environmental monitoring and assessment》2014,186(6):3743-3753
There is worldwide concern over the increase use of nanoparticles (NPs) and their ecotoxicological effect. It is not known if the annual production of tons of industrial nanoparticles (NPs) has the potential to impact terrestrial microbial communities, which are so necessary for ecosystem functioning. Here, we have examined the consequences of adding the NPs particularly the metal oxide (CuO, ZnO) on CH4 oxidation activity in vertisol and the abundance of heterotrophs, methane oxidizers, and ammonium oxidizers. Soil samples collected from the agricultural field located at Madhya Pradesh, India, were incubated with either CuO and ZnO NPs or ionic heavy metals (CuCl2, ZnCl2) separately at 0, 10, and 20 μg g?1 soil. CH4 oxidation activity in the soil samples was estimated at 60 and 100 % moisture holding capacity (MHC) in order to link soil moisture regime with impact of NPs. NPs amended to soil were highly toxic for the microbial-mediated CH4 oxidation, compared with the ionic form. The trend of inhibition was Zn 20?>?Zn 10?>?Cu 20?>?Cu 10. NPs delayed the lag phase of CH4 oxidation to a maximum of 4-fold and also decreased the apparent rate constant k up to 50 % over control. ANOVA and Pearson correlation analysis (α?=?0.01) revealed significant impact of NPs on the CH4 oxidation activity and microbial abundance (p?<?0.0001, and high F statistics). Principal component analysis (PCA) revealed that PC1 (metal concentration) rendered 76.06 % of the total variance, while 18.17 % of variance accounted by second component (MHC). Biplot indicated negative impact of NPs on CH4 oxidation and microbial abundance. Our result also confirmed that higher soil moisture regime alleviates toxicity of NPs and opens new avenues of research to manage ecotoxicity and environmental hazard of NPs. 相似文献