Fugitive dust is an important source of particulate matters (PM) emission in the air. Vegetation barriers (VBs) can be an effective way to mitigate PM from fugitive dust sources. It is meaningful to choose appropriate plants to establish VBs that can efficiently capture PM from various sources. This study was conducted to establish comparable and repeatable conditions to evaluate the capability of different VB species in mitigating PM emission from certain fugitive dust source. The airflow around two VBs and their PM interception mechanism was studied in a wind tunnel with simulated PM emission source of animal feeding operations. The species used for the two VBs were conifers represented by Pinus Sylvestris var. mongolica Litv. (PS) and the broad-leaved species represented by Syringa Oblate Lindl. (SOL). The results showed that the interception efficiency of the PS vegetation barrier was only slightly lower than that of SOL vegetation, while the PS had a lower effect on the wind speed at the similar leaf surface area. On the other hand, there were a large number of disordered “ridged” stripes on the microscopic structure of the hydrophilic leaves of SOL and PS, and a large amount of fine particles deposited on the leaves were observed, indicating that the microscopic geometric surface structure increased the deposition efficiency of the particles. These findings help to better understand the potential of tree species to reduce PM in environments. Implications: To evaluate the capability of different VB species in mitigating PM emission from certain fugitive dust source, airflow around the two VBs and their PM interception mechanisms were studied in wind tunnels with comparable and repeatable conditions. The results showed that the interception efficiency of the Pinus Sylvestris var. mongolica Litv. (PS) was only slightly lower than that of the Syringa Oblate Lindl. (SOL) vegetation, while the PS had a lowering effect on the wind speed at the same low leaf surface area. Microscopic analysis of leaves surface indicated that the microscopic characteristics increased the deposition efficiency of the particles.
1 May 2020 in International Journal of Agricultural and Biological Engineering
With the development of concentrated animal feeding operations in China, the air pollution problem has drawn widespread public attention. Residents living near farms are suffering from the emissions of particulate matter (PM) and odors. However, scientific data on the characteristics of these emissions are limited to the establishment and evaluation of mitigation strategies in China. This study was conducted to provide fundamental information on the concentrations of PM inside and outside a typical ventilated laying hen house in northeastern China. The results showed that outdoor PM concentrations of this laying hen house did not meet the requirements of the environmental quality standard of China's livestock and poultry farms in the two days out of six sampling days in summer, while indoor PM concentrations met the environmental requirements during this study. The indoor and outdoor PM concentrations were highly correlated in summer, and over 60% of particles indoor were emitted outside via mechanical ventilation. There were more fine particles dominated both inside and outside of the laying hen house. Besides, twelve and nine elements were measured from the PM sources inside and outside laying hen house, respectively. PM control strategies may be adjusted based on the status of exhaust fans, the ages of laying hens, atmospheric conditions, and routine house management to well reduce PM emissions and improve control efficiency.
Air pollutants, such as particulate matter (PM) and ammonia (NH3), generated by intensive animal farming pose considerable threats to human health, animal welfare, and ecological balance. Conventional materials are often ineffective at simultaneously removing multiple pollutants, maintaining a low pressure drop, and ensuring durability in heavily polluted environments. Inspired by the dust-retention properties of Pinus sylvestris var. mongolica (PS) needles, this study developed a biomimetic grooved ribbon fiber using electrospinning technology. These fibers were further assembled into a three-dimensional bioinspired aerogel structure through freeze-forming technology to achieve efficient dust capture. Additionally, the introduction of UiO-66-NH2 nanoparticles significantly enhanced the properties of the aerogels for NH3 adsorption. Among the various prepared aerogels (PG, UPG-5, UPG-10, UPG-15, and UPG-20), UPG-10 demonstrated the best performance, achieving a filtration efficiency of 99.24% with a pressure drop of 95 Pa. Notably, it exhibited a remarkable dust-holding capacity of 147 g/m2, and its NH3 adsorption capacity reached 99.89 cm3/g, surpassing PG aerogel by 31.46 cm3/g. Additionally, UPG-10 exhibited outstanding elasticity, maintaining over 80% of its original shape after 30 compression cycles. This biomimetic aerogel presents a promising solution for air purification, contributing to improved agricultural efficiency and environmental sustainability.