Wind Erosion Dust Research Articles

Localization of Soil Wind Erosion Dust Emission Factor in Beijing

Soil wind erosion dust is one of the primary sources of fine particulate matter (PM2.5). Compared with the fugitive dust emission inventory of typical domestic provinces and cities, we found that the maximum among the contribution rates of soil wind erosion dust to the local total fugitive dust PM2.5 emission inventory was about 4 orders of magnitude higher than the minimum. This study provided a wind erosion equation and a determination method of parameter values. The remote sensing interpretation, China soil dataset, and meteorological data of each district in Beijing were used to achieve the spatial distribution of the vegetation coverage factor (V), soil erodibility index (I), and climatic factors (C) in the plain area of Beijing. This study also estimated the emission factor of soil wind erosion dust and its spatial distribution. The main conclusions are as follows: ① Taking 2017 and Beijing city as an example, it was found that the climatic factor (C) was underestimated to different extents by domestic scholars, and PM2.5 emission factors were overestimated or underestimated. ② V, I, and C showed apparent spatial differences and the average values of them were 0.63±0.09, 188±73, and 0.029±0.009, respectively. The maximum values of V, I, and C were 1.5, 2.1, and 4.5 times the minimum among all districts, respectively. ③ The PM2.5 emission factor of soil wind erosion dust in Beijing showed a high spatial distribution in the northwest and southeast. The average emission factor of the city was (0.0018±0.0008) t·(hm2·a)-1, which is 0.54 times the highest emission factor (Xicheng District) and 3.12 times the lowest (Pinggu District). The area proportions of standardized emission factors with higher intensity (0.6 to 0.8] and high intensity (0.8 to 1.0] was 0.72% and 0.04%, respectively.

A quantitative assessment of atmospheric emissions and spatial distribution of trace elements from natural sources in China

Natural sources, such as soil and wind-erosion dust (SWD), biomass open burning (BOB), sea salt spray (SSAS) and biogenic source (BIO), are major contributors to atmospheric emissions of trace elements (TEs) globally. In this study, we used a comprehensive approach to account for area-, production- and biofuel consumption-based emission factor calculation methods, and thus developed an integrated high-resolution emission inventory for 15 types of TEs (As, B, Cd, Co, Cr, Cu, Hg, Mn, Mo, Ni, Pb, Sb, Se, V and Zn) originated from natural sources in China for the year 2015. The results show that national emissions of TEs in 2015 range from 7.45 tons (Hg) to 1, 400 tons (Zn) except for the extremely high emissions of Mn (10, 677 tons). SWD and BIO are identified as the top two source contributors, accounting for approximately 67.7% and 26.1% of the total emissions, respectively. Absolute emissions of TEs from natural sources are high in the Xinjiang, Inner Mongolia and Tibet autonomous regions with large areas of bare soil and desert. However, emission intensity of TEs per unit area in the Southern provinces of China is higher than those in Northern China and Southwestern China, with the Yunnan and Sichuan provinces displaying the highest emission intensity. Our results suggest that controlling SWD can play a significant role in reducing fugitive particulate matter and the associated emissions of TEs from natural sources in China; and desertification control is particularly critical in the Northwest provinces where the majority of deserts are located.

Application of Test Method for Dust Suppression Efficiency of Wind Erosion Dust Suppressant

Wind erosion dust suppressant is an effective measure for controlling wind erosion dust. This study used the Portable In-Situ Wind Erosion Laboratory (PI-SWERL) to evaluate the efficiency of domestic and foreign dust suppressants and to compare their control efficiency of PM2.5 in terms of spraying methods, dilution factors, and wind speed. The following results were noted.① According to the recommended dilution factor, G and Enviroseal (ES) dust suppressant solutions were treated and tested, respectively. The control efficiency of particulate matter with diameters less than 2.5 μm (PM2.5) corresponding to the droplet spraying method was better than the atomized spraying method; the G dust suppressant efficiency, at 99.5%, was better than ES and water, at 94.0% and 77.5%, respectively, at 17.2 m·s-1, which is equivalent to grade 8 wind. ② The G dust suppressant with dilution factors of 50, 100, 150, 200, and 400 times was tested. The dust suppression efficiency at a wind speed of 17.2 m·s-1 was 99.7%, 99.5%, 99.7%, 98.1%, and 95.9%, respectively. The best cost-effective dilution factor of G dust suppressant was 150 times. The efficiency of dust suppressants increased when the wind speed increased between 13.1 m·s-1 and 17.2 m·s-1. ③ The method of using PI-SWERL to test the efficiency of wind erosion dust suppressant can quantify the suppression efficiency of dust suppressant on PM2.5. It is recommended to conduct dust suppression during effective periods and to practice environmentally friendly methods of wind erosion dust suppression.

Emission Characteristics of Wind-Eroded Dust from Concrete Batching Plants in Beijing

Concrete batching plants are a typical source of fugitive dust in Beijing. In this study, two concrete batching plants in Beijing were used to test wind erosion of dust with a Portable In-suit Wind Erosion Laboratory (PI-SWERL) designed by the Desert Research Institute (DRI). Sand and aggregate storage piles and paved roads in concrete batching plants were tested to determine the emission characteristics of wind eroded dust. Combining the frequencies of disturbance of storage piles and paved road surface with local meteorological data, localized wind erosion dust emission factors of PM2.5 were established. Results demonstrate that:①There are small differences in daily average emission factors for PM2.5 between the aggregate warehouse entrance area, concrete loading area, social road import area, and concrete batching plant entrance area, with these being 0.45, 0.41, 0.31, and 0.30 kg·(hm2·d)-1, respectively. ②Daily average emission factors for PM2.5 of coarse stone, fine stone, coarse sand, and fine sand storage piles are 0.10, 0.12, 0.26, and 2.02 kg·(hm2·d)-1, respectively. Emission factors of fine sand storage piles are 20.5, 16.8, and 7.7 times greater than those of coarse stone, fine stone, and coarse sand, respectively, and spring emission factors are 6.4, 3.4, and 1.3 times greater than those of summer, autumn, and winter, respectively. ③Daily average emission factors for PM2.5 of storage piles and paved roads are 1.13 and 0.37 kg·(hm2·d)-1, respectively 3.9 and 1.3 times higher than the wind erosion factor from storage piles from AP-42 files (c11s12 concrete batching, 1995); the uncertainty range of the emission factor is 34%-92%. ④It is recommended to strengthen watering, sweeping, and cleaning of paved roads, and to ensure fully enclosed storage and use of spray water to reduce wind erosion of dust from storage piles, especially from fine sand piles.

Emission Characteristics of Wind Erosion Dust from Topsoil of Urban Roadside-Tree Pool

This study characterized the wind erosion dust emissions from topsoil of urban roadside-tree pool. The study area is the Xicheng District of Beijing and uses GIS to obtain the spatial distribution of various road mileages. A full bore investigation method was carried out to survey tree pool in the Zhanlanlu Subdistrict to obtain the activity level of tree pool in the Xicheng district. The portable in situ wind erosion laboratory (PI-SWERL) was used to determine the emission factors of PM2.5 from the wind erosion dust from tree pool and to estimate the PM2.5 emission inventory of tree pool in the Xicheng District in 2016. The results showed that:①The annual emission factors per unit area of PM2.5 from tree pool of freeways' frontage roads, major roads, minor roads, and alleys are 47.9, 7.9, 14.9, and 29.9 g·(m2·a)-1, respectively. The reduction rate of PM2.5 emission factors from tree pool by precipitation was about 30.3% in 2016. ②The annual emission factors per unit mileage of PM2.5 from the tree pool of freeways' frontage roads, major roads, minor roads, branch roads, and alleys are 2.57, 2.33, 4.04, 7.31, and 5.44 kg·(km·a)-1, respectively, and the factors for branch roads are 1.3, 1.8, 2.8, and 3.1 times as much as those for alleys, minor roads, freeways' frontage roads, and major roads, respectively. Taking the emission factor for minor roads as an example, the winter emission factor is 1.3, 7.3, and 8.7 times greater than that in the spring, summer, and autumn, respectively. ③PM2.5 emissions from the tree pool in the Xicheng District of Beijing are 1.60 t·a-1, and the uncertainty range of the emission inventory is -143%~184%. The emissions in winter are 0.68 t·a-1, which are 1.1, 1.42, and 5.1 times greater than that in the spring, summer, and fall, respectively. The emission values for freeways' frontage roads, major roads, minor roads, collectors, and alleys account for 5.6%, 8.7%, 23.2%, 4.1%, and 58.4% of the total emissions, respectively. It is recommended that the urban roadside-tree pool be covered to reduce wind erosion dust emissions with materials that do not affect the growth of trees as soon as possible.

Study on Discharge and Diffusion of Raised Dust during Subgrade Construction in the Yellow River Flood Area

The construction process of subgrade construction was divided into several operating units：oil material loading and unloading, vehicle transportation and wind erosion dust. For each operational unit during each stage of subgrade construction, different Gaussian diffusion models were chosen respectively according to the transmission and diffusion of raised dust from different source (point source, line source and area source). Finally, based on one contract section on a freeway in the Yellow River flood area, the concentration distribution was calculated using atmospheric estimation software in different pattern of point source, line source and area source. It was shown that with the increasing of distance, point source and area source emission increased to the maximum value and then decreased to the stable value, while line source emission presented a distribution pattern which changed decreasingly.