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Underground coal mining destroys overlying strata, and phreatic aquifer above the panel is destabilized, causing phreatic water level (PWL) variation. On-site monitoring of the PWL variation throughout the mining period is of great significance to the management and conservation of groundwater resources in arid and semiarid mining areas. The research on the decline of the PWL when phreatic aquifer leakage is concentrated, but there is little research on the fluctuation characteristics of PWL under the condition of phreatic aquifer without leakage. Therefore, using the #108 coalface in the Jinjitan colliery of the Yushenfu mining area as a case study to carry out the research on PWL fluctuation induced by underground coal mining. First, phreatic water without leakage throughout the coal mining period in the #108 coalface was determined. Second, considering surface subsidence induced by mining activities and PWL in fluviograph comprehensively, true PWL fluctuation characteristics were analyzed throughout the whole coal seam mining period. It is concluded that the buried depth of PWL presented a trend of "decreasing sharply—increasing sharply—decreasing slowly—increasing slowly—becoming stable" in the monitoring period of 1 year. Furthermore, a well flow model was established to simulate the PWL variation process before and after coal mining and to predict the PWL recovery time after coal mining. On these bases, the error analysis of the measured and predicted PWL recovery time, the relationship between the PWL fluctuation and the residual aquiclude thickness, the impact of rainfall on PWL recovery, the response of surface vegetation eco-environment, and phreatic water resources management and conservation were discussed. These research results are important for achieving a win–win situation strategy that balances the exploitation of coal resources and the conservation of phreatic water resources, promoting the sustainable development of coal mining. [ABSTRACT FROM AUTHOR]

[Display omitted] • Tar induced severe deactivation of SCR catalyst is first reported in China. • Proposed pyrolysis effectively removes the poisoning substances. • Heating rate is the critical factor to keep a superior mechanical property. • The generated catalyst show activity as high as the fresh catalyst. • Regeneration of SCR catalyst shows favorable environmental and economic benefits. Tar species on catalyst's surface promote the deposition of NH 4 HSO 4 /(NH 4) 2 SO 4 leading to the complete deactivation of V 2 O 5 -MoO 3 /TiO 2 catalyst utilized in a glass kiln. The proposed pyrolysis method in this work effectively removes the poisoning substances. TG-IR and TG-MS results indicate that the pyrolysis products are mainly CO 2 and SO 2 representing the pyrolysis of tar species and NH 4 HSO 4 /(NH 4) 2 SO 4. The heating rate and pyrolysis temperature are the critical factors to keep a superior mechanical property. The axial and transverse compressive strength remained 1.77 MPa and 0.53 Mpa falling only by 4.8% and 13.1% respectively through the optimized treatment at 420 °C for 2 h with heating rate of 3 K min−1. The characterizations indicated that the surface area, pore volume and acid property were apparently restored after the heat treatment. As a result, the regenerated powder catalyst showed 100% NO conversion and more than 94% N 2 selectivity at 250 – 300 °C and the regenerated honeycomb catalyst exhibited 91.6% NO conversion at 260 °C. The TPR and XPS results indicated changes of the redox behavior, which contracted the temperature range of excellent performance. Typically, the redox cycles shifting to high temperatures narrowed this temperature range, while the excessive oxidation ability decreased the N 2 selectivity. The schematic of tar induced deactivation and regeneration was proposed. Overall, the tar induced deactivated catalyst was successfully regenerated by proper pyrolysis and can be reutilized in the original glass kiln at 260 °C. [ABSTRACT FROM AUTHOR]