This study presents a method for remediating soils contaminated by organic pollutants through the selective blocking of pores. This technique is based on the use of yield stress fluids, specifically concentrated biopolymer solutions, which, due to their distinctive rheological properties, preferentially flow through high-conductance flow paths. Following the injection of yield stress fluid, its presence redirects subsequent water flow towards the pores that are typically unswept during standard waterflooding. Laboratory experiments at the pore scale were conducted to validate this method and confirm previous findings from core-flooding experiments. Aqueous xanthan gum solutions were used as microscopic blocking agents in well-characterized micromodels exhibiting microscopic heterogeneities in pore size. The impact of polymer concentration, soil wettability and operating conditions (injection pressure and flow rate) on the residual pollutant saturation following treatment was analyzed, enabling the optimization of the remediation strategy. The use of xanthan gum as a blocking agent led to a significant improvement in pollutant removal compared to conventional waterflooding, delivering consistently better results across all cases studied. The method demonstrated strong performance in water-wet medium, with the average polymer concentration yielding the highest efficiency in pollutant removal.

In recent years, prominent spacefaring nations have redirected their attention towards the Moon as potential avenue for economic prospects and as a pivotal waypoint for extended space exploration endeavors. Nonetheless, a notable concern has emerged regarding the dispersion of lunar dust during lunar landings, a phenomenon that has been associated with documented instances of equipment damage during prior missions. To mitigate these challenges, leading research institutions are actively engaged in endeavors aimed at minimizing the adverse effects of dust dispersal during lunar and extraterrestrial landings. This review paper provides a comprehensive overview of ongoing research and development endeavors focusing on the interaction dynamics between rocket plumes and lunar surfaces, along with the resultant dispersion of lunar dust triggered by rocket plume impingement. Additionally, it presents research efforts aimed at developing lunar dust mitigation technologies.

To ensure the mud discharge performance of the atmospheric cutterhead and reduce the risk of clogging, it is necessary to consider the distribution of soil in the cutterhead opening under different tunneling parameters. Taking the Haizhuwan tunnel project as an example, the rheological properties of soil and slurry samples were collected and analyzed. The full-scale mud discharge model of cutterhead was established for the first time by using the Euler multiphase flow model. By examining the pressure value of the monitoring point of the excavation chamber, the simulation parameters agree with the field-measured data. The simulation results show that the soil content in the center area and the edge area of the cutterhead is more than 60% and 15% respectively, which is much higher than that in other areas. The mathematical model of soil content and tunneling parameters was established, and the measures to reduce the soil content were explored. By comprehensively analyzing the variation law of soil content in the central and edge areas, it is beneficial to improve the mud discharge performance of the cutterhead by reducing the penetration rate and increasing the cutterhead rotation speed and grouting rate.