The present study was conducted to characterize emission from a heavy duty diesel engine equipped with a particulate trap filter (DPF). A city bus with a wall-flow monolith particulate trap filter and bypass system was tested under steady state operating conditions for comparison of regulated and unregulated emissions. Furthermore, gas and particulate emissions during regeneration treatment with electric heater were measured. Diesel exhaust particulate and volatile organic matter were collected from the diluted exhaust gas with fluorocarbon coated glass fiber filters and amberlite XAD-2 resin respectively. The filters and resin were extracted with dichloromethane using Soxhlet extraction to collect the soluble organic fraction of particulate matter (SOF) and volatile organic matter (VOM). The SOF and the VOM were chemically analysed and their mutagenicity was evaluated with a modified Ames assay. DPF was effective for the reduction of particulate matter including PAH and mutagenic compounds. Particulate matter emitted during regeneration of DPF mostly consisted of SOF containing PAH, which showed mutagenicities.
Emissions inventories of suspended particulate matter (SPM) from anthropogenic sources in Japan were created based on the input-output tables covering about 400 sectors in 1990 and 1995. The SPM emissions from each sector were estimated as products of energy consumption by fuel type and SPM emission factors specific for fuel and industry. Total national emission was 34.0 × 104 t/y in 1995 and the contribution of stationary sources was 46 %. Emission from electricity and gas supply sector was the largest and occupied 14 % of the stationary sources. The emission from mobile sources including tire wear of cars was estimated to be 18.4 × 104 t/y. The tire wear greatly contributed to the national total emissions and was 9 % in total. We also made an analysis on a relationship between SPM emissions and the domestic final demand by the input-output approach. Direct emissions and the embodied emissions were calculated by sector and it was found that the indirect emissions were not negligible for service industries.
In order to utilize low-grade coals, which contain high concentrations of sulfur (2-6 wt. %) and ash (>15 wt. %, dry basis), controlling pollutant emissions during combustion in domestic stoves and small-capacity industrial boilers, a composite solid fuel “coal-biomass briquette” with sulfur fixation function was produced in a pilot plant in Chongqing city, China. It was composed of 80 wt. % of low-grade coal and 20 wt. % of biomass (e. g., wood chips and agricultural wastes) with a small fraction of sulfur-fixation additives. In this study, we investigated the ignition and combustion characteristics of the coal-biomass briquettes, and developed a new sulfur fixation additive made from sub-product in gas welding industries. It was found that the coal-biomass briquette has the lower ignition temperature and higher combustion efficiency than the usual coal briquettes, and that the newly developed additive was superior to limestone or scallop shells in sulfur fixation capability. This method is simple, economical, and efficient, in terms of emission control of SO2, CO and other particulate pollutants from the combustion of low-grade coals using the conventional domestic stoves and boilers without modification. The coal-biomass briquette can be applicable for pollution control of coal combustion in some developing countries.
In order to identify organic contaminants in cleanroom air, cleanroom air is passed through an adsorbent which entraps the organic contaminants. The organic contaminants are released from the adsorbent and introduced to a gas chromatography-mass spectrometer (GC-MS). This method enables 0.1 μg/m3 level analysis for organic compounds in cleanroom air with the Total Ion Monitoring Mode, and 0.02 μg/m3 with the Selective Ion Monitoring Mode. Qualitative and quantitative analysis of cyclosiloxanes, phosphates and phthalates are conducted by the use of standards, i. e., the comparison of retention time of the gas chromatogram and the mass spectrum of each peak. Other organic compounds are identified by the comparison of mass spectrum to the standard mass spectrum data. The peak areas of these organic compounds are converted to the concentrations with toluene calibration curve. Compounds detected are mainly aliphatic hydrocarbons and aromatic hydrocarbons and their delivatives, siloxanes, phosphates and phthalates. The source of these compounds are mainly the cleanroom itself and the intake air.