Air quality. Certification of automated dust arrestment plant monitors for use on stationary sources. Performance criteria and test procedures

2015 ◽  
Keyword(s):  
Air Quality ◽  
Performance Criteria ◽  
Test Procedures ◽  
Quality Certification ◽  
Stationary Sources

Application of Electron Optics to Characterization of Particulate Pollutants

1972 ◽  
Vol 30 ◽  
pp. 364-365
Author(s):  
J. B. Moran ◽  
J. L. Miller
Keyword(s):  
Air Quality ◽  
Quality Standards ◽  
Ambient Air ◽  
Hazardous Substances ◽  
Fuel Additives ◽  
Ambient Air Quality ◽  
Air Quality Standards ◽  
Emission Standards ◽  
Stationary Sources ◽  
Ambient Air Quality Standards

The Clean Air Act Amendments of 1970 provide the basis for a dramatic change in Federal air quality programs. The Act establishes new standards for motor vehicles and requires EPA to establish national ambient air quality standards, standards of performance for new stationary sources of pollution, and standards for stationary sources emitting hazardous substances. Further, it establishes procedures which allow states to set emission standards for existing sources in order to achieve national ambient air quality standards. The Act also permits the Administrator of EPA to register fuels and fuel additives and to regulate the use of motor vehicle fuels or fuel additives which pose a hazard to public health or welfare.National air quality standards for particulate matter have been established. Asbestos, mercury, and beryllium have been designated as hazardous air pollutants for which Federal emission standards have been proposed.

scholarly journals Evaluating wildfire emissions projection methods in comparisons of simulated and observed air quality

2019 ◽  
Author(s):  
Uma Shankar ◽  
Donald McKenzie ◽  
Jeffrey P. Prestemon ◽  
Bok Haeng Baek ◽  
Mohammed Omary ◽  
...  
Keyword(s):  
Air Quality ◽  
Regional Differences ◽  
Dynamical Downscaling ◽  
Projection Methods ◽  
Performance Criteria ◽  
Yield Model ◽  
Secondary Chemistry ◽  
Emissions Inventory ◽  
Socioeconomic Changes ◽  
Modeling Uncertainties

Abstract. Climate warming has been implicated as a major driver of recent catastrophic wildfires world-wide but analyses of regional differences in U.S. wildfires show that socioeconomic factors also have a large role. We previously leveraged statistical projections of annual areas burned (AAB) over the fast-growing Southeastern U.S. that include both climate and socioeconomic changes from 2011 to 2060, and developed wildfire emissions estimates over the region at 12-km × 12-km resolution to enable air quality (AQ) impact assessments for 2010 and selected future years. These estimates employed two AAB datasets, one using statistical downscaling (statistical d-s), and another using dynamical downscaling (dynamical d-s) of climate inputs from the same climate realization. This paper evaluates these wildfire emissions estimates against the U.S. National Emissions Inventory (NEI) as a benchmark in contemporary (2010) simulations with the Community Multiscale Air Quality (CMAQ) model, and against network observations for ozone and particulate matter below 2.5 µm in diameter (PM2.5). We hypothesize that our emissions estimates will yield model results that meet acceptable performance criteria, and are comparable to those using the NEI. The three simulations, which differ only in wildfire emissions, compare closely, with differences in ozone and PM2.5 below 1 % and 8 % respectively, but have much larger maximum mean fractional biases (MFBs) against observations (25 % and 51 % respectively). The largest biases for ozone are in the fire-free winter, indicating that modeling uncertainties other than wildfire emissions are mainly responsible. Statistical d-s, with the largest AAB domain-wide, is 7 % more positively biased and 4 % less negatively biased in PM2.5 on average than the other two cases, while dynamical d-s and the NEI differ only by 2 %–3 % partly because of their equally large summertime PM2.5 underpredictions. Primary species (elemental carbon, and ammonium from ammonia) have good-to-acceptable results, especially for the downscaling cases, providing confidence in our emissions estimation methodology. Compensating biases in sulfate (positive), and in organic carbon and dust (negative) lead to acceptable PM2.5 performance. As these species are driven by secondary chemistry or non-wildfire sources, their production pathways can be fruitful avenues for CMAQ improvements. Overall, the downscaling methods match, and sometimes exceed the NEI in simulating current wildfire AQ impacts, while enabling such assessments much farther into the future.

scholarly journals Model Performance Differences in Sulfate Aerosol in Winter over Japan Based on Regional Chemical Transport Models of CMAQ and CAMx

Atmosphere ◽  
2018 ◽  
Vol 9 (12) ◽  
pp. 488 ◽  
Author(s):  
Syuichi Itahashi ◽  
Kazuyo Yamaji ◽  
Satoru Chatani ◽  
Kunihiro Hisatsune ◽  
Shinji Saito ◽  
...  
Keyword(s):  
Air Quality ◽  
Deposition Velocity ◽  
Model Performance ◽  
Chemical Transport ◽  
Sulfate Aerosol ◽  
Performance Criteria ◽  
Second Phase ◽  
Transport Models ◽  
Chemical Transport Models ◽  
So2 Concentration

Sulfate aerosol (SO42−) is a major component of particulate matter in Japan. The Japanese model intercomparison study, J-STREAM, found that although SO42− is well captured by models, it is underestimated during winter. In the first phase of J-STREAM, we refined the Fe- and Mn-catalyzed oxidation and partly improved the underestimation. The winter haze in December 2016 was a target period in the second phase. The results from the Community Multiscale Air Quality (CMAQ) and Comprehensive Air quality Model with eXtentions (CAMx) regional chemical transport models were compared with observations from the network over Japan and intensive observations at Nagoya and Tokyo. Statistical analysis showed both models satisfied the suggested model performance criteria. CMAQ sensitivity simulations explained the improvements in model performance. CMAQ modeled lower SO42− concentrations than CAMx, despite increased aqueous oxidation via the metal catalysis pathway and NO2 reaction in CMAQ. Deposition explained this difference. A scatter plot demonstrated that the lower SO42− concentration in CMAQ than in CAMx arose from the lower SO2 concentration and higher SO42− wet deposition in CMAQ. The dry deposition velocity caused the difference in SO2 concentration. These results suggest the importance of deposition in improving our understanding of ambient concentration behavior.

Grinding With Abrasive Disks: Part 1—Test Procedures and Performance Criteria

1962 ◽  
Vol 84 (4) ◽  
pp. 431-441 ◽  
Author(s):  
W. A. Mohun
Keyword(s):  
Performance Criteria ◽  
Test Procedures ◽  
Cutting Rate ◽  
And Performance ◽  
Effective Life

Equipment and procedures for test grinding abrasive disks and for coating such disks in the laboratory are described. Criteria useful in evaluating performance are defined and discussed. Discard criteria for worn disks are analyzed and the suggestion made that the effective life of the disk ends when the cutting rate is some specified percentage of its initial cutting rate. This paper is the first of a series dealing with the mechanism of the cutting action of abrasive disks.

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