Public Research Seminar by Sustainable Energy and Environment Thrust, Function Hub, HKUST(GZ) - 1. Microsensor Applications for Dispersed Particulate Emissions Monitoring in an Industrial Area丨2. Emission Rates and Compositions for Open Burning of Household Wastes
- Open burning of household solid waste is a large source of air pollutants worldwide, especially in developing countries. However, waste burning emissions are either missing or have large uncertainties in local, regional, or global emission inventories due to limited emission factor and activity data. Detailed particulate matter (PM) chemical speciation data is even scarcer. To meet this need, emission factors (EF) and source profiles were determined for ten waste categories common to household wastes, including paper, leather/rubber, textiles, plastic bottles, plastic bags, vegetation (with three different moisture content levels), food discards, and combined materials. Carbonaceous materials constituted more than 70% of PM2.5 mass. Plastic bags have the highest carbon content and the highest combustion efficiency, leading to the highest EFs for CO2. Textiles have the highest nitrogen and sulfur content, resulting in the highest EFs for nitrogen oxides (NOx ) and sulfur dioxide (SO2). Emissions are similar for vegetation with 0% and 20% moisture content; however, EFs for CO and PM from the vegetation with 50% moisture content are 3 and 20–30 times, respectively, those from 0% and 20% moisture content. Elemental carbon (EC) was most abundant from flaming materials (e.g., plastic bags, textile, and combined materials) and its climate forcing exceeded the corresponding CO2 emissions by a factor of 2–5. Chlorine had the highest EFs among elements measured by X-ray fluorescence (XRF) for all materials; vegetation emissions showed high abundances of potassium, consistent with its use as a marker for biomass burning emission. Fresh PM emitted from waste burning appeared to be acidic. Moist vegetation and food discards had the highest EFs of hydrogen fluoride (HF) and particulate fluoride due to fluorine accumulation in plants, while the rubber sample had the highest EFs of hydrogen chloride (HCl) and particulate chloride due to high chlorine in the rubber. Plastic bottles and bags, rubber, and food discards had the highest EFs for polycyclic aromatic hydrocarbons (PAHs) and nitro-PAHs as well as their associated toxicity. Particle size distributions show abundant ultrafine particles with modes in 14-170 nm. Flaming combustion particles (mostly unimodal) show higher concentrations and narrower distribution than smoldering combustion particles (some as bimodal). Data from this study will be useful for health and climate impact assessment, speciated emission inventory, source-oriented dispersion models, and receptor-based source apportionment.
- The ArcelorMittal integrated steel mill in Serra, Espírito Santo, Brazil, has installed and operates a unique real-time particulate matter (PM) monitoring system to estimate real-world fugitive dust emissions, quantify off-site transport, and provide real-time feedback to implement remedial actions. The system consists of 45 towers that monitor PM and 15 towers that monitor PM wind speeds and wind directions at 3 m, 10 m, and 20 m above ground level. Several stations are located around suspected emission areas that include materials handling, stockpiling, and industrial processes such as coking and sintering. Other stations are located around the facility periphery to determine on-site and off-site transport. The stations are equipped with EcoSoft ECOPR-N3 monitors using Alphasense NG3 optical particle counters to sense PM concentrations owing to their ability to count individual particles which are translated to mass concentrations assuming a 2 g/cm3 PM density and spherical shape. These are further calibrated in a test chamber using a mixture of fugitive dust samples typical of the facility. Total Suspended Particulate (TSP, aerodynamic diameters < ~30 µm) are currently reported, but the detailed size distributions permit modification to regulated size fractions such as PM2.5 and PM10 (particles with aerodynamic diameters ≤ 2.5 and ≤ 10 µm aerodynamic diameters, respectively). PM emission rates are derived by defining boundaries around source areas and calculating horizontal fluxes into and out of these regions. Data are acquired in real time, with 10 min averages and made accessible through temporal and spatial displays. Action levels are set that result in messages to environmental managers and source area supervisors to implement control measures. This novel system is still under development, but it holds potential to improve emission inventories and direct remediation measures where and when they are most needed.
1. Dr. John G. Watson, Nevada System of Higher Education (NSHE)
Dr. John G. Watson, Research Professor in the Division of Atmospheric Sciences (DAS) at the Desert Research Institute (DRI), part of the Nevada System of Higher Education (NSHE), has over 50 years of experience in physics, environmental sciences, air quality network design and measurement, and source/receptor modeling. He received his Ph.D. in Environmental Sciences from Oregon Graduate Institute (now Oregon Health and Science University) in 1979. Dr. Watson has conducted and managed >120 air quality studies. He is known for formulating conceptual models as well as organizing and planning large-scale, multi-year air quality studies in the U.S. Dr. Watson established DRI’s Source Characterization Laboratory and developed an in-plume sampling system for real-time measurement of vehicle exhaust. Dr. Watson is the principal author or co-author of more than 500 peer-reviewed publications and book chapters and has been recognized by ISIHighlyCited.com in ecology and environment with over 31,000 citations of his work and an h-index of 92. He can be reached at john.watson@dri.edu.
2. Dr. Judith C. Chow, Nevada System of Higher Education (NSHE)
Dr. Judith C. Chow, Nazir and Mary Ansari Chair in Entrepreneurialism and Science and Research Professor in the Division of Atmospheric Sciences (DAS) at the Desert Research Institute (DRI), part of the Nevada System of Higher Education (NSHE), has over 40 years of experience conducting air quality studies and performing statistical data analysis. She received her Doctor of Science degree in Environmental Health Science and Physiology from Harvard University in 1985. As leader of DRI’s Environmental Analysis Facility (EAF), Dr. Chow supervises a group of 20 research scientists and technicians in developing and applying advanced analytical methods to characterize suspended atmospheric particles. She served as chartered committee member of the U.S. EPA’s Clean Air Scientific Advisory Committee (CASAC) for setting national ambient air quality standards. Dr. Chow is the principal author or co-author of more than 500 peer-reviewed articles and book chapters and has been recognized by ISIHighlyCited.com in ecology and environment with over 32,000 citations of her work and an h-index of 96. She can be reached at judith.chow@dri.edu.
For inquiries, please contact Miss Suggi WU (+86-20-88332966, suggilswu@ust.hk )