In-Field Ambient Fine Particle Monitoring of an Outdoor Wood Boiler: Public Health Concerns

Outdoor wood boilers (OWBs) are detached wood-fired units that heat water used for domestic consumption and heating. The increasing use of OWBs has prompted regulatory concern because of escalating public complaints. Few field studies of OWB ambient emissions have been conducted, limiting efforts to assess this air quality problem. A screening level evaluation was conducted to characterize ambient fine particle (PM_2.5) levels nearby an OWB device and to overview operating and design factors that could influence PM_2.5 levels. High hourly (186 μ g/m³ 4.3 h mean, 665 μg/m³ 95th percentile) and peak continuous (8,880 μg/m³ 15 s avg) PM_2.5 concentrations were found within 50–150 ft of an OWB relative to background levels throughout the course of nearly routine operating conditions. Values were highest during air intake within 1 h of fuel loading (416 μg/m³ 1 h mean) compared to air-starved 22–24 h after loading (115 μg/m³ 3.3 h mean). OWB features that could affect PM_2.5 levels include exemption from federal wood stove standards, poor combustion design, large firebox capacity, trash burning use, low stack height, and four-season utility. In view of cardiac and respiratory health risks associated with transient exposure to ambient PM_2.5 at levels well below those reported here, this pilot study contributes to the risk assessment field by identifying an emerging problem of potential public health significance.     

The promotive effect of combustion products from plant vegetation on the release of seeds from dormancy

In darkness, dormancy was imposed on seeds of lettuce (Lactuca sativa L. cv. Grand rapids) by high temperature and on seeds of oilseed rape (Brassica napus L. cv. Apex) by osmotic stress using polyethylene glycol (PEG 8000). In both cases, dormancy was broken by incubating the seeds in aqueous extracts of combustion products from Salix viminalis wood chips or Themeda triandra leaves. Dormancy of rapeseed, but not lettuce, was also broken by a solution of smoke from burnt straw of Triticum aestivum. The greatest stimulation from burnt vegetation was achieved with an aqueous extract of pyrolysed willow wood chips, which had been subjected to temperatures of up to 800 °C during combustion in a down-draught gasifier. This suggests that some biologically active substances obtained from combustion of plant tissues are highly heat-stable.     

BEVSIM: Battery electric vehicle sustainability impact assessment model

To achieve climate neutrality ambitions, greenhouse gas emissions from the transport sector need to be reduced by at least 90% by 2050. To support industry and policy makers on mitigating actions on climate goals it is important to holistically compare and reduce life cycle environmental impacts of road passenger vehicles. A web-based sustainability assessment tool named battery electric vehicle sustainability impact assessment model, BEVSIM, is developed to assess the environmental, circularity, and economic performance of the materials, sub-systems, parts, and individual components of battery electric vehicles and internal combustion engine vehicles. This tool allows to measure and compare impacts resulting from recycling technologies, end-of-life scenarios, and future scenarios resulting from changes in grid mixes. This paper explains the purpose of the tool, its functionality and design as well as the underlying assumptions.     

Elevated standard metabolic rate in a freshwater shrimp (Palaemonetes paludosus) exposed to trace element-rich coal combustion waste

I conducted a transplant experiment to determine whether standard metabolic rate (SMR) of a freshwater shrimp (Palaemonetes paludosus) would be affected by exposure to trace element-enriched coal combustion waste (‘coal ash'). Shrimp were transplanted into replicate cages in a coal ash-polluted site and a reference site for 8 months. The coal ash-polluted site was characterized by elevated sediment concentrations of As, Cd, Cr, Cu, Ni, Pb, and Se compared to sediments in the reference site. After 8 months in the study sites, shrimp in the polluted site appeared to have accumulated As, Cd, and Se from the habitat, but there were no differences in survival between the study sites. However, mean SMR of shrimp (measured as O₂ consumption at rest) held in the polluted site was 51% higher than mean SMR of shrimp held in the reference site. The elevation in SMR indicates that the energetic costs of maintenance are greater for shrimp chronically exposed to the coal-ash polluted environment than shrimp in the reference site. It is likely, therefore, that other physiological or behavioral processes may be modified in the pollution-exposed individuals to compensate for the increased energy demands for maintenance. Recent studies have reported similar elevations in SMR in an amphibian and a reptile chronically exposed to coal ash. Analogous physiological responses in such taxonomically diverse animals (a crustacean, an amphibian, and a reptile) indicate that elevated SMR may be a general response by many types of organisms exposed to the mixture of trace elements characteristic of coal ash. The relationships among pollution-induced elevations in maintenance expenditures, long-term health of individuals, and population-level parameters require further attention.     

Spheroidal carbonaceous particles as a marker for recent sediment distribution

We have tested the hypothesis that spheroidal carbonaceous particles (SCP), emitted from oil and coal combustion, can be used as a marker for recent sediment distribution in lake basins. Sediment traps have been used to study when and how the particles are introduced into a lake, a laboratory experiment has been made to study the depositional behaviour of the particles in relation to other sedimentary constituents, and spatial SCP distributions have been surveyed in three lakes. The results support the hypothesis that SCP can be used as a marker, and also indicate that acidification can change sediment distribution in lakes.     

Preparation and Evaluation of Hybrid Composites of Chemical Fuel and Multi-walled Carbon Nanotubes in the Study of Thermopower Waves

When a chemical fuel at a certain position in a hybrid composite of the fuel and a micro/nanostructured material is ignited, chemical combustion occurs along the interface between the fuel and core materials. Simultaneously, dynamic changes in thermal and chemical potentials across the micro/nanostructured materials result in concomitant electrical energy generation induced by charge transfer in the form of a high-output voltage pulse. We demonstrate the entire procedure of a thermopower wave experiment, from synthesis to evaluation. Thermal chemical vapor deposition and the wet impregnation process are respectively employed for the synthesis of a multi-walled carbon nanotube array and a hybrid composite of picric acid/sodium azide/multi-walled carbon nanotubes. The prepared hybrid composites are used to fabricate a thermopower wave generator with connecting electrodes. The combustion of the hybrid composite is initiated by laser heating or Joule-heating, and the corresponding combustion propagation, direct electrical energy generation, and real-time temperature changes are measured using a high-speed microscopy system, an oscilloscope, and an optical pyrometer, respectively. Furthermore, the crucial strategies to be adopted in the synthesis of hybrid composite and initiation of their combustion that enhance the overall thermopower wave energy transfer are proposed.     

Novel blue‐emitting SrMg2Al16O27:Eu2+ phosphor for solid‐state lighting

Eu²⁺‐activated SrMg₂Al₁₆O₂₇ novel phosphor was synthesized by a combustion method (550°C furnace). The prepared phosphor was first characterized by X‐ray diffraction (XRD) for confirmation of phase purity. SEM analysis showed the morphology of the phosphor. The photoluminescence characteristics showed broad‐band excitation at 324 nm, which was monitored at 465 nm emission wavelength. The SrMg₂Al₁₆O₂₇:Eu²⁺ phosphor shows broad blue emission centred at 465 nm, emitting a blue light corresponding to 4f⁶5d¹ → 4f⁷ transition. Here we report the photoluminescence characteristics of the prepared phosphor and compare it with commercial BAM:Eu²⁺ phosphor. Copyright © 2011 John Wiley & Sons, Ltd.     

Time Dependent Strength and Stiffness of PCC Bottom Ash-Bentonite Mixtures

Utilization of bottom ash from burning of pulverized coal in construction-related applications has received some attention within the last decade. Its use in geotechnical engineering applications is still very limited, however. Within the last few years several studies have been completed to evaluate strength, stiffness, and durability properties of pulverized coal combustion (PCC) bottom ash mixed with various admixtures. Studies have shown that the physical properties of bottom ash obtained from burning of pulverized coal are similar to that of natural sand with particle sizes ranging from fine gravel to fine sand and low percentages of silt and clay sized particles. However, unlike sand, chemical composition of bottom ash results in change of strength and stiffness characteristics of the bottom ash-admixture mixtures with time. In this study, change in strength and stiffness characteristics of Illinois PCC bottom ash and bentonite mixtures with time are evaluated. A series of unconfined compression tests on bottom ash-bentonite mixtures at various curing ages was performed in the laboratory. Results presented show that strength and stiffness of bottom ash-bentonite mixtures changed significantly with time.     

Fuel-dependent,shape-selective,distinct blue and green photoluminescence from α-Bi2O3 and β-Bi2O3 synthesised using microwave combustion

In the current study, α-Bi₂O₃ and β-Bi₂O₃ were synthesised using a one-step, novel, solid–solid combustion technique. The reaction rate was increased with the use of microwaves (molecular heating) compared to direct or indirect heating. A strong relationship was observed between the fuel, polymorphic structure, shape and optical properties of the synthesised Bi₂O₃. Photoluminescence studies reveal that two major visible emissions are observed for all samples. The two emissions are distinct with a broad peak in blue and a narrow peak in green. The intensity of the green characteristic emission depends strongly on the heating method used for synthesis and is more intense for microwave-synthesised samples.     

Flue gas desulfurization gypsum improves orchardgrass root density and water extraction in an acid subsoil

In Appalachia, many soils are acidic, high in exchangeable aluminium, and low in calcium. Large amounts of high gypsum flue gas desulfurization (FGD) by-products are currently disposed of into landfills, although they have potential value as a soil amendment for the region. This study was conducted to determine if leaching an acid subsoil with a saturated solution of a FGD by-product can improve the subsoil as a rooting media for orchardgrass (Dactylis glomerata L.) which is widely used for pasture in the region. Orchardgrass was grown in soil from a pHc 3.8 (in 0.01 M CaCl₂) Lily loam Bt horizon (fine loamy siliceous, mesic, Typic Hapludult) leached with two different rates of a saturated FGD by-product aqueous solution, as well as in soil that was limed, and an unamended soil. Water use by a clipped and partially enclosed vegetative canopy was measured in a growth chamber during two drying cycles. Small but consistent increases in water use were correlated with decreases in aluminium saturation of the soil. The effect was greatest during the second drying cycle. Increases in root biomass were also correlated with decreases in aluminium saturation. The effect of treatment on the pattern of water use altered after the first drying cycle when water uptake became most restricted in the unamended treatment. The manganese content of leaf tissue increased from 208 mg kg^-1 to 570 mg kg^-1 between the unaltered and highest leaching rate treatment. The highest level was still below the 2000 mg kg^-1 that is considered toxic to grazing animals. These results suggest that the application of high gypsum FGD by-products to pastures in Appalachia has the potential to improve root growth and functioning in subsoil horizons, but some care may be needed to monitor forage quality.