Exhaust emission inventory of typical construction machinery and its contribution to atmospheric pollutants in Chengdu, China.

To study the emission characteristics of typical construction machinery in Chengdu, 12 construction machinery (excavators, bulldozers, loaders, and forklifts) under idling mode, moving mode, and working mode, were tested using a portable emission measurement system (PEMS). Under three operating modes, the typical construction machinery in the working mode was higher in the fuel-based average emission factors of PM2.5 and NOx, while the fuel-based average emission factors of HC and CO were higher in idling mode. Integrated the results of investigation on ownership and activity levels of construction machinery, an exhaust emission inventory of typical construction machinery of Chengdu in 2018 was established according to the recommendation method. The annual emission of PM2.5, NOx, HC, and CO were 1.67 × 106, 1.61 × 108, 3.83 × 106, and 1.26 × 107 kg, respectively, and the excavator contributed the maximum emissions, accounting for an average proportion of 43.95%. The emission of construction machinery in Chengdu exhibited a clear monthly trend, with the highest from April to October and the lowest from November to March. In addition, the exhaust emissions presented an obvious spot-like characteristics, and the high-value areas were mainly concentrated in the surrounding suburban counties such as Shuangliu Wenjiang etc. To reduce pollution from construction machinery and improve the quality of the atmospheric environment, more effective measures on housing construction and municipal construction should be taken in those districts in Chengdu.

[Trends in Vehicle Emissions in Sichuan Province, 2010-2017].

Vehicle pollution in Sichuan Province is becoming increasingly serious. Here, based on specific inventory calculation methods and multi-caliber activity level data, this study calculated vehicle exhaust emissions from 2010 to 2017 in Sichuan Province. The results show that the average growth rate of vehicle ownership in Sichuan is higher than the national trend. In 2017, vehicle emissions of CO, NOx, SO2, NH3, HC, PM2.5, PM10, BC, and OC were 706.9, 275.3, 0.3, 5.7, 164.8, 8.1, 8.9, 4.1, and 1.4 kt, respectively. Except for NH3, showed a downward trend, peaking in 2014-2016. Diesel vehicle ownership showed a strong correlation with the emission of NOx. Based on these observations, stricter vehicle emission standards offer the greatest potential for emissions reductions, with early implementation offering the greatest reduction potential. The improvement of fuel quality will also have more than a 6% emission reduction effect on pollutant emission each year. HC and NOx emissions reductions will be an important control on vehicle pollution in Sichuan Province in the future.

[Fine Particulate Matter Source Profile of Typical Industries in Sichuan Province].

An electrical low pressure impactor particle monitor was used to monitor typical industries in Sichuan Province, such as cement, glass, ceramic, brick-tile, coal-fired boiler, biomass boiler, power plant, and steel industry. Fine particulate matter source profiles of each industry were developed based on the laboratory analysis. The results showed that Si, Ca, and Mg were the major elements of building industry particulate matter emission. Sulfate emission from double sodium-calcium was higher than from other desulfurization technologies in the building industry. The main chemical components of PM2.5 from power plants were SO42-, Ca2+, NH4+, Mg, and Si, while OC, Al, Si, and Ca were the main chemical components of PM2.5 from coal-fired boilers. The content of OC was the most abundant in biomass briquette boiler particulate matter emissions, followed by K and EC. In term of the biomass fuel boiler PM2.5 source profile, OC, EC, and Cl- were the major chemical components. Ca was the largest component of PM2.5 from the steel industry, accounting for 18.11% of the total PM2.5 emission, followed by SO42-, Na+, and Fe.