South Coast Air Quality Management District Research Articles

Spatial trends and sources of PM2.5 organic carbon volatility fractions (OCx) across the Los Angeles Basin

In this study, we used the positive matrix factorization (PMF) model to apportion the sources of organic carbon volatility fractions (OCx) as well as total OC concentrations in five different locations across the Los Angeles Basin, including West Long Beach, Anaheim, central Los Angeles (CELA), Rubidoux, and Fontana over the period from July 2012 to June 2013. Total OC as well as OC volatility fractions (OC1-OC4), measured with the thermal-optical analysis as part of the fourth Multiple Air Toxics Exposure Study (MATES IV) by the South Coast Air Quality Management District (SCAQMD), in combination with gaseous and particulate source tracers (such as NOx, O3, particulate sulfate, K+/K ratio, and biomass-burning originated black carbon (BCbb)) were used as inputs to the PMF model. A 3-factor solution, including traffic, secondary organic aerosols (SOA), and biomass burning, was found to be the most physically interpretable solution. Average total OC concentrations showed an upward trend from the sites closer to the coast (i.e., 3.7 ± 1.9 μg m−3 at West Long Beach) to inland downwind sites (i.e., 4.8 ± 1.8 μg m−3 at Fontana), especially in the warm season, suggesting the major impact of SOA formation on total OC concentrations. Source apportionment results indicated that traffic is the dominant contributor to OC2 and OC3 fractions, especially at the sites that are near major primary sources such as CELA and West Long Beach, with corresponding contributions of 60 ± 1.0% and 79 ± 1.7% to OC2 and 53 ± 0.9% and 64 ± 1.3% to OC3, respectively. On the other hand, SOA was found to be the dominant contributor to OC4 fraction, especially at the receptor sites located further inland, with corresponding contributions of 66 ± 1.0% in Rubidoux and 56 ± 0.7% in Fontana. Our results also indicated that traffic is the dominant source of total OC concentrations, with an average contribution of 53 ± 2.4% at all the sites, followed by SOA formation and biomass burning, contributing to 40 ± 1.8% and 7 ± 0.8% of total OC concentrations, respectively. The contribution of traffic and biomass burning to total OC concentrations increased during the cold season, while that of SOA became more significant during the warm season when photochemical activities peak. Results from the present study provided important insight on the sources and spatio-temporal variations of OC volatility fractions as well as total OC concentrations in PM2.5 across the Los Angeles Basin.

Projected changes in particulate matter concentrations in the South Coast Air Basin due to basin-wide reductions in nitrogen oxides, volatile organic compounds, and ammonia emissions

ABSTRACTAn ozone abatement strategy for the South Coast Air Basin (SoCAB) has been proposed by the South Coast Air Quality Management District (SCAQMD) and the California Air Resources Board (ARB). The proposed emissions reduction strategy is focused on the reduction of nitrogen oxide (NOx) emissions by the year 2030. Two high PM2.5 concentration episodes with high ammonium nitrate compositions occurring during September and November 2008 were simulated with the Community Multi-scale Air Quality model (CMAQ). All simulations were made with same meteorological files provided by the SCAQMD to allow them to be more directly compared with their previous modeling studies. Although there was an overall under-prediction bias, the CMAQ simulations were within an overall normalized mean error of 50%; a range that is considered acceptable performance for PM modeling. A range of simulations of these episodes were made to evaluate sensitivity to NOx and ammonia emissions inputs for the future year 2030. It was found that the current ozone control strategy will reduce daily average PM2.5 concentrations. However, the targeted NOx reductions for ozone were not found to be optimal for reducing PM2.5 concentrations. Ammonia emission reductions reduced PM2.5 and this might be considered as part of a PM2.5 control strategy.Implications: The SCAQMD and the ARB have proposed an ozone abatement strategy for the SoCAB that focuses on NOx emission reductions. Their strategy will affect both ozone and PM2.5. Two episodes that occurred during September and November 2008 with high PM2.5 concentrations and high ammonium nitrate composition were selected for simulation with different levels of nitrogen oxide and ammonia emissions for the future year 2030. It was found that the ozone control strategy will reduce maximum daily average PM2.5 concentrations but its effect on PM2.5 concentrations is not optimal.

Monitoring the 2016 LA County Sand Fire with Multiple Early Detection Systems

ObjectiveTo detect increases in health complaints resulting from the July2016 Sand Fire near Santa Clarita, CA using syndromic surveillanceand complementary systems.IntroductionOn July 22, 2016, the Sand Fire began burning in the Santa ClaritaValley of Los Angeles County (LAC), CA. This urban-adjacentwildfire breached the city limits of Santa Clarita (population 180,000).Fueled by record heat and an ongoing exceptional drought, the SandFire burned over 40,000 acres in 13 days1and caused a large increasein the air concentration of fine particulate matter2. The syndromicsurveillance team was tasked with reporting on possible health effectsfrom the fire. Fire, asthma, and heat related data were monitoreduntil the fire was reported as 98% contained. The team prepared anddistributed a daily special summary report to key stakeholders in theLAC Department of Public Health.MethodsEmergency department (ED) data were queried for cases relatedto fire, asthma, cardiac events, eye irritation, heat, and total volume.These queries consisted of key word searches within chief complaint(CC), diagnosis and triage note data fields. Queries were conductedon all participating syndromic EDs in LAC, and also restricted to nineEDs closest to the fire. The resulting line lists were reviewed dailyto rule out visits that were unrelated to the Sand Fire. The fire querywas refined periodically with additional exclusion terms. Complaintsrelated to asthma were tallied in a second query. In order to assessheat-related ED visits and temperature trends, existing queries andreport templates were modified to focus on the nine fire-area EDs.Local temperatures were taken from the Weather Undergroundwebsite. Complementary systems were also monitored, includingover-the-counter medication sales and nurse hotline call data. Trendgraphs for hospital admissions and ED visits were produced daily toassess volume from 19 Reddinet participating hospitals. In additionto internal data sources, the South Coast Air Quality ManagementDistrict website was checked daily to monitor air quality in the SantaClarita Valley.ResultsThere were 48 syndromic ED patient records with direct mention ofthe fire in LAC’s syndromic hospitals in 13 days. Of these, 26 did notinclude asthma, and 32 came from the nine hospitals in the Sand Fireregion; 32 were identified from the CC, six by diagnosis and ten bytriage note. Despite an increase in fire-related visits, overall trends inED data were not affected; no increase was found for cardiac events,eye irritation, heat-related illness or total volume. Asthma visitsincreased at the time of the fire, which correlates with a sharp increasein the concentration of fine particulate matter in the Santa ClaritaValley following the start of the fire2. However, these increases wereno higher than other peaks observed in previous months3. No increasesin calls to a nurse hotline or over-the-counter medication sales wereobserved. Among Reddinet hospitals, admissions increased slightlybut ED visits remained unchanged.ConclusionsFor the Sand Fire, ED volume alone was not enough to estimatethe subsequent health effects on residents of LAC; instead a specificfire query was needed. Several factors could explain why overalltrends were not affected. In a region where air quality is alreadycompromised, it is challenging to distinguish between asthmaincreases from air pollution from those exacerbated by wildfiresmoke. It is also likely that residents heeded warnings about air qualityduring active fires, thus reducing their outdoor exposure. Althoughthe majority of cases were identified using the CC field, additionaldata fields such as triage notes available from some hospitals improvethe ability to elicit fire related visits. Regardless of the challengespresented in measuring health effects related to wildfires, syndromicsurveillance and complementary systems continue to be the primarytools for near real-time assessments in LAC.

Particulate matter emissions and gaseous air toxic pollutants from commercial meat cooking operations

This study assessed the effectiveness of three novel control technologies for particulate matter (PM) and volatile organic compound (VOC) removal from commercial meat cooking operations. All experiments were conducted using standardized procedures at University of California, Riverside's commercial test cooking facility. PM mass emissions collected using South Coast Air Quality Management District (SCAQMD) Method 5.1, as well as a dilution tunnel-based PM method showed statistically significantly reductions for each control technology when compared to baseline testing (i.e., without a catalyst). Overall, particle number emissions decreased with the use of control technologies, with the exception of control technology 2 (CT2), which is a grease removal technology based on boundary layer momentum transfer (BLMT) theory. Particle size distributions were unimodal with CT2 resulting in higher particle number populations at lower particle diameters. Organic carbon was the dominant PM component (>99%) for all experiments. Formaldehyde and acetaldehyde were the most abundant carbonyl compounds and showed reductions with the application of the control technologies. Some reductions in mono-aromatic VOCs were also observed with CT2 and the electrostatic precipitator (ESP) CT3 compared to the baseline testing.

PM2.5 and ultrafine particulate matter emissions from natural gas-fired turbine for power generation

The generation of electricity from natural gas-fired turbines has increased more than 200% since 2003. In 2007 the South Coast Air Quality Management District (SCAQMD) funded a project to identify control strategies and technologies for PM2.5 and ultrafine emissions from natural gas-fired turbine power plants and test at pilot scale advanced PM2.5 technologies to reduce emissions from these gas turbine-based power plants. This prompted a study of the exhaust from new facilities to better understand air pollution in California. To characterize the emissions from new natural gas turbines, a series of tests were performed on a GE LMS100 gas turbine located at the Walnut Creek Energy Park in August 2013. These tests included particulate matter less than 2.5 μm in diameter (PM2.5) and wet chemical tests for SO2/SO3 and NH3, as well as ultrafine (less than 100 nm in diameter) particulate matter measurements. After turbine exhaust was diluted sevenfold with filtered air, particle concentrations in the 10–300 nm size range were approximately two orders of magnitude higher than those in the ambient air and those in the 2–3 nm size range were up to four orders of magnitude higher. This study also found that ammonia emissions were higher than expected, but in compliance with permit conditions. This was possibly due to an ammonia imbalance entering the catalyst, some flue gas bypassing the catalyst, or not enough catalyst volume. SO3 accounted for an average of 23% of the total sulfur oxides emissions measured. While some of the SO3 is formed in the combustion process, it is likely that the majority formed as the SO2 in the combustion products passed across the oxidizing CO catalyst and SCR catalyst.The 100 MW turbine sampled in this study emitted particle loadings of 3.63E-04 lb/MMBtu based on Methods 5.1/201A and 1.07E-04 lb/MMBtu based on SMPS method, which are similar to those previously measured from turbines in the SCAQMD area (FERCo et al., 2014), however, the turbine exhaust contained orders of magnitude higher particles than ambient air.

Heterogeneity among motorists in traffic-congested areas in southern California

Estimation of congestion costs, presumed to be one of the largest external costs of automobile travel, is typically based on a single value of time delay for motorists in metropolitan areas. However, the estimation may be wrong if the profiles of motorists are different at different times of day. This study uses a survival model to examine the demographic and socioeconomic profiles of motorists at different times of day at congested locations in southern California, by using on-road remote-sensing measurements and license plates images obtained in 2007 and 2008 by the California South Coast Air Quality Management District (SCAQMD). More than 80,000 vehicles were observed from fifteen selected study sites over fifteen days. Their plates, through anonymized registration records, revealed addresses at the census block group level, which have homogenous profiles by construction. Motorists’ profiles at different times of day display large variation, however, according to extended Cox model with a non-parametric baseline hazard, which is used to accommodate both the time-invariant and time-varying effects of the covariates. This study thus proposes a new approach to examine heterogeneity among motorists.

The evolution and impact of testing baghouse filter performance

In 1995, the U.S. Environmental Protection Agency (EPA) initiated the Environmental Technology Verification (ETV) program for the purpose of generating both independent and credible performance verification of innovative technologies and helping to accelerate acceptance of these products into the marketplace to further benefit the environment and protect public health. The EPA has approved a testing protocol under this program to verify the performance of commercially available filtration products for pulse-jet baghouses in removing fine particulate matter (aerodynamic diameter <2.5 μm; PM2.5). This verification testing protocol was later used as a basis for the development of the American Society for Testing and Materials (ASTM) Method D6830-02 and the International Organization for Standardization (ISO) Method 11057. The South Coast Air Quality Management District (SCAQMD) in California and the EPA's Office of Air Quality Planning and Standards (OAQPS) highly encourage the use of ETV/ASTM-verified filtration media. This paper highlights the evolution of the standard test methods, the EPA's and SCAQMD's regulatory activities, the benefits of using verified filtration media, and the importance of including the filter performance testing in future consideration of baghouse permitting, baghouse operation and maintenance (O&M) plans, quality assurance/quality control (QA/QC), and bag monitoring plans. Implications: Environmental engineers, managers, and the public will benefit from the information related to the PM2.5 emissions documented in the EPA's Environmental Technology Verification (ETV) program for baghouse filtration products. The South Coast Air Quality Management District and the EPA's Office of Air Quality Planning and Standards are in support of the ETV program. Baghouse users are recommended to use the ETV-verified filtration products and incorporate the performance testing in their baghouse monitoring program. This action will reduce air pollution and create a positive impact on public health and public relations.

Environmental Justice and Green‐Technology Adoption

AbstractThis paper presents an analysis of an environmental justice (EJ) program adopted by the South Coast Air Quality Management District (SCAQMD) as a part of its regulation to phase out a toxic chemical used by dry cleaners. SCAQMD provided financial incentives to switch early and gave establishments in EJ neighborhoods priority in applying for grants. Despite this pro‐EJ policy, available data show that dry cleaners in low‐income, predominantly minority, and EJ‐designated areas were less likely to be an early adopter of green technologies, and this finding holds even after accounting for firm and market characteristics. Dry cleaners in disadvantaged neighborhoods were also less likely to receive a grant to switch technology despite the district's effort to set aside half of the funding for applicants from EJ areas.

Traffic-Related Air Toxics and Term Low Birth Weight in Los Angeles County, California

Background: Numerous studies have linked criteria air pollutants with adverse birth outcomes, but there is less information on the importance of specific emission sources, such as traffic, and air toxics.Objectives: We used three exposure data sources to examine odds of term low birth weight (LBW) in Los Angeles, California, women when exposed to high levels of traffic-related air pollutants during pregnancy.Methods: We identified term births during 1 June 2004 to 30 March 2006 to women residing within 5 miles of a South Coast Air Quality Management District (SCAQMD) Multiple Air Toxics Exposure Study (MATES III) monitoring station. Pregnancy period average exposures were estimated for air toxics, including polycyclic aromatic hydrocarbons (PAHs), source-specific particulate matter < 2.5 μm in aerodynamic diameter (PM2.5) based on a chemical mass balance model, criteria air pollutants from government monitoring data, and land use regression (LUR) model estimates of nitric oxide (NO), nitrogen dioxide (NO2) and nitrogen oxides (NOx). Associations between these metrics and odds of term LBW (< 2,500 g) were examined using logistic regression.Results: Odds of term LBW increased approximately 5% per interquartile range increase in entire pregnancy exposures to several correlated traffic pollutants: LUR measures of NO, NO2, and NOx, elemental carbon, and PM2.5 from diesel and gasoline combustion and paved road dust (geological PM2.5).Conclusions: These analyses provide additional evidence of the potential impact of traffic-related air pollution on fetal growth. Particles from traffic sources should be a focus of future studies.

SCAQMD may impose fees on coatings products

SCAQMD may impose fees on coatings products

SCAQMD may impose fees on coatings products

SCAQMD may impose fees on coatings products

Source apportionment of VOCs in the Los Angeles area using positive matrix factorization

Eight 3-h speciated hydrocarbon measurements were collected daily by the South Coast Air Quality Management District (SCAQMD) as part of the Photochemical Assessment Monitoring Stations (PAMS) program during the summers of 2001–03 at two sites in the Los Angeles air basin, Azusa and Hawthorne. Over 30 hydrocarbons from over 500 samples at Azusa and 600 samples at Hawthorne were subsequently analyzed using the multivariate receptor model positive matrix factorization (PMF). At Azusa and Hawthorne, five and six factors were identified, respectively, with a good comparison between predicted and measured mass. At Azusa, evaporative emissions (a median of 31% of the total mass), motor vehicle exhaust (22%), liquid/unburned gasoline (27%), coatings (17%), and biogenic emissions (3%) factors were identified. Factors identified at Hawthorne were evaporative emissions (a median of 34% of the total mass), motor vehicle exhaust (24%), industrial process losses (15%), natural gas (13%), liquid/unburned gasoline (13%), and biogenic emissions (1%). Together, the median contribution from mobile source-related factors (exhaust, evaporative emissions, and liquid/unburned gasoline) was 80% and 71% at Azusa and Hawthorne, respectively, similar to previous source apportionment results using the chemical mass balance (CMB) model. There is a difference in the distribution among mobile source factors compared to the CMB work, with an increase in the contribution from evaporative emissions, though the cause (changes in emissions or differences between models) is unknown.

Laboratory and Field Evaluation of Instrumentation for the Semicontinuous Determination of Particulate Nitrate (and Other Water-Soluble Particulate Components)

Studies conducted at the U.S. Environmental Protection Agency facility in Research Triangle Park, NC, and at a field study in Southern California have demonstrated the capability for the semicontinuous determination of particulate nitrate (and other water-soluble ionic species). Two instruments, an R&P Series 8400N Ambient Particulate Nitrate Monitor (8400N) and an ion chromatography (IC)-based prototype monitor developed at Texas Tech University, were evaluated both in the laboratory using aqueous standards and simulated ambient aerosols and in the field during a 3-week (July 1–21, 2003) joint ambient comparison study with Brigham Young University and the South Coast Air Quality Management District (SCAQMD). The field study was conducted at the SCAQMD Rubidoux field site near Riverside, CA. During initial (before the field study) laboratory studies, both instruments were responsive to changes in the simulated aerosol concentration. However, potential problems were discovered involving both instruments during the laboratory-based studies both before and after the Rubidoux study, and these problems are currently being addressed. During the 3-week field study period, 15-minute average particulate nitrate concentrations approaching 30 μg/m3 were observed. Because of malfunctioning IC components (concentrator columns) of the Texas Tech University prototype monitor, limited data were obtained from this instrument during the 3-week sampling period. Initial ambient comparisons show general agreement between the 8400N and IC-based prototype instrument for the semicontinuous determination of ambient particulate nitrate at lower nitrate concentrations (<15 μg/m3) and an underdetermination by the 8400N at higher concentrations (>15 μg/m3). A decreased molybdenum converter efficiency in the pulse analyzer of the 8400N discovered during postfield study laboratory evaluation may explain the negative bias observed at higher nitrate concentrations. Semicontinuous results obtained from U.S. Environmental Protection Agency-operated instruments were averaged and compared with integrated sampler results obtained by Brigham Young University and SCAQMD.

SCAQMD votes to ban perc drycleaners

SCAQMD votes to ban perc drycleaners

Characterization of PM25 and PM10 in the South Coast Air Basin of Southern California: Part 2—Temporal Variations

ABSTRACT The South Coast Air Quality Management District (SCAQMD) conducted a 1-year special particulate monitoring study from January 1995 to February 1996. This monitoring data indicates that high PM10 and PM2 5 concentrations were observed in the fall (October, November, and December), with November concentrations being the highest. During the rest of the year, PM2.5 and PM10 masses gradually increased from January to September. Monthly PM10 mass varied from 20 to 120 |ig/m3, and monthly PM25 mass varied from 13 to 63 |j.g/m3. The PM2.5-to-PM10 ratio varied daily and ranged between 22 and 96%. Two types of high-PM days were observed. The first type was observed under fall stagnation conditions, which lead to high secondary species concentrations. The second type was observed under high wind conditions, which lead to high primary coarse particles of crustal components. The highest 24-hr average PM10 concentration (226.3 |ig/m3) was observed at the Fontana station, while the highest PM25 concentration (129.3 |ig/m3) was observed at the Diamond Bar station.

Characterization of PM25 and PM10 in the South Coast Air Basin of Southern California: Part 1—Spatial Variations

ABSTRACT In December 1994, the South Coast Air Quality Management District (SCAQMD) initiated a comprehensive program, the PM10 Technical Enhancement Program (PTEP), to characterize fine PM in the South Coast Air Basin (SCAB). A 1-year special particulate monitoring project was conducted from January 1995 to February 1996 as part of the PTEP. Under this enhanced monitoring, HNO3, NH3, and speciated PM10 and PM2.5 concentrations were measured at five stations (Anaheim, downtown Los Angeles, Diamond Bar, Fontana, and Rubidoux) in the SCAB and at one background station at San Nicolas Island. PM2.5 and PM10 mass and 43 individual species were analyzed for a full chemical speciation of the particle data. The PTEP data indicate that the most abundant chemical components of PM10 and PM25 in the SCAB are NH4+ (8-9% of PM10 and 14-17% of PM25), NO3 - (23-26% of PM10 and 28-41% of PM25), SO4= (6-11% of PM10 and 9-18% of PM2 5), organic carbon (OC) (15-19% of PM10 and 18-26% of PM2.5), and elemental carbon (EC) (5-8% of PM10 and 8-13% of PM25). On an annual average basis, PM25 comprises 52-59% of the SCAB PM10. Annual average PM10 and PM2.5 concentrations showed strong spatial variations, low at coastal sites and high at inland sites. Annual average PM10 concentrations varied from 40.8 ug/m3 at Anaheim to 76.8 ug/m3 at Rubidoux, while annual average PM2.5 concentrations varied from 21.7 ug/m3 at Anaheim to 39.8 ug/m3 at Rubidoux. The chemical characterizations of the PM2.5 and PM10 concentrations, as well as their spatial variations, were examined; the important findings are summarized in this paper, and the temporal variations are discussed in the companion paper.1

Nitrate Artifacts during PM25 Sampling in the South Coast Air Basin of California

ABSTRACT In February 1993, the South Coast Air Basin (SCAB) was redesignated as a “serious” nonattainment area for PM10. To improve the understanding and characterization of fine particulate matter in the SCAB, the South Coast Air Quality Management District (SCAQMD) initiated a comprehensive PM10 Technical Enhancement Program (PTEP). Using enhanced PTEP monitors (specially designed multichannel/multifilter samplers), a one-year fine particulate matter (PM) monitoring program was initiated in January 1995. As part of the special monitoring program, nitric acid, ammonia, and speciated PM10 and PM2.5 concentrations were measured at five locations in the SCAB (downtown Los Angeles, Anaheim, Diamond Bar, Fontana, and Rubidoux) and at one background station (San Nicolas Island). The PM2.5 data are the first spatially resolved speciated data collected in the SCAB on an annual basis. Within the SCAB, where nitrate is a major component of PM2.5, nitrate losses have been documented. The spatial and temporal variations of the nitrate losses during PM2.5 sampling and the uncertainties of the nitrate losses are discussed. Significant losses occur at a low mass range, between 10 and 50 ìg/m3. Significant gains occur at an even lower mass range of less than 30 ìg/m3. On an annual average basis, nitrate losses vary between 1.25 and 2.32 ìg/m3 and the SCAB-wide average value of nitrate loss is 1.8 ìg/m3 based on five PTEP stations in the SCAB. The maximum nitrate losses for each station vary from 6.4 ìg/m3 to 22.5 ìg/m 3. Theoretical prediction of the sampling efficiency of the nitrate during PM2.5 sam - pling was compared with the PTEP data. In general, theoretical prediction was in good agreement with measured values.

Population Density, Particulate Emission Characterization, and Impact on the Particulate Inventory of Smoking Vehicles in the South Coast Air Quality Management District

ABSTRACT The impact of high-particulate-emission vehicles on the total light-duty vehicle particulate emission inventory in the South Coast Air Quality Management District (SCAQMD) has been estimated by an analysis of the SCAQMD's CUT-SMOG database, a field survey of smoking vehicles, and particulate emissions testing of representative smoking vehicles. The field study, carried out at 61 sites throughout the SCAQMD, showed that 1.11%-1.75% of the vehicles in the light-duty fleet emit visible smoke. This fleet of smoking vehicles is composed mainly of older vehicles, 8 to 18 years of age. Particulate emission testing of 23 smoking vehicles gave an average Federal Test Procedure (FTP) weighted emission rate of 399 mg/mi with a range of 64-2,323 mg/mi, while the average IM240 emission rate was 346 mg/mi, with a range from 13-1,807 mg/mi. The contribution of light-duty smoking vehicles to the particulate emissions inventory in the SCAQMD is estimated to be 0.51-0.81 tons per day.

South Coast Air-Quality Management District (SCAQMD)

Current landfills emit copious quantities of methane, which is typically flared on-site. Such flaring results in significant emissions of oxides of nitrogen (NOx), as well as potentially serious levels of toxics, greenhouse gases, and other flare gas contaminants. The district has worked closely with TeraMeth Industries (TMI) to establish the first demonstration plant in the world that will divert the gaseous waste stream from the BKK Landfill, located in West Covina, CA, through a syngas synthesis process, and produce 50 metric tons/d of methanol. Multiple replication of this technology is projected by TMI to be commercially competitive with worldwide methanol production economics. For example, contractual commitments for the long-term purchased product have been obtained. Permitting issues unique to landfills, such as site-specific gas composition, have also been addressed as part of this project. This article identifies: 1. The air-quality context of this facility; 2. The key permitting issues being addressed to facilitate the construction and operation of this facility; and 3. The commercial and economic implications of the plant design, including the potential future markets for this conversion technology.

Determination of the Size Distribution and Chemical Composition of Fine Particulate Semivolatile Organic Material in Urban Environments Using Diffusion Denuder Technology

AbstractCollection of particles on a filter results in underestimation of particulate organic compounds due to losses from the semivolatile organic fraction during sample collection, that is, a “negative sampling artifact.” This sampling-induced change in the phase distribution of semivolatile organic material resulted in the loss of an average of 35% of the particulate organic material in samples collected at the South Coast Air Quality Management District (SCAQMD) sampling site at Azusa, CA, in the Los Angeles Basin. These semivolatile organic compounds lost from particles were measured using two diffusion denuder sampling systems. A multichannel diffusion denuder sampling system (BOSS) was used to determine the concentrations of fine particulate carbonaceous material, and a multisystem, multichannel, high-volume diffusion denuder sampler (BIG BOSS) was used for the determination of the particle size distribution and chemical composition of semivolatile organic compounds in fine particles. Results obtai...