煤矸石基多孔材料对矿区复垦基质水分运动的影响
Effects of coal gangue-based porous materials on water movement in reclaimed substrates of mining areas
-
摘要: 针对矿区表土稀缺的复垦难题,为评估煤矸石基多孔材料作为土壤重构材料的可行性,通过一维垂直土柱试验,系统探究了不同掺量(10%~30%)的多孔材料对复垦基质水分入渗与蒸发的影响。结果表明,多孔材料能加快湿润锋运移速率,提高累积入渗量,且湿润锋运移距离始终大于对照组。累积入渗量随掺量增加呈先增后减趋势,在掺量为25%时达到最大值。湿润锋运移距离及累积入渗量与入渗时间的关系符合幂函数和Kostiakov模型。蒸发过程中,该材料在中期促进蒸发,后期在低掺量条件下具有保水作用。盆栽试验进一步验证,在水分胁迫下,该材料可提高黑麦草叶绿素含量,减轻土壤板结,增强植物抗旱性。环境安全性评估结果表明,该材料重金属含量及浸出毒性均低于国家相关标准限值。综合分析显示,煤矸石基多孔材料在掺量为25%时持水效果最优,具有矿区生态恢复应用潜力。研究结果阐明了多孔材料影响水分运动的作用机制,揭示了土壤孔隙结构与水分运动之间的构效关系,为矿区蓄水保墒与复垦实践提供科学依据。Abstract: To address the challenge of topsoil scarcity during mine reclamation and to evaluate the feasibility of coal gangue -based porous material as a soil reconstruction medium,one-dimensional vertical soil column experiments were conducted to systematically investigate the effects of different incorporation rates (10%-30%) of the porous material on water infiltration and evaporation in a reclaimed substrate. The results showed that the porous material accelerated wetting front migration rate and increased cumulative infiltration,with the wetting front migration distance consistently exceeding that of the control group. The cumulative infiltration exhibited an initial increase followed by a decrease with increasing incorporation rate,reaching a maximum at 25%. The relationships of wetting front migration distance and cumulative infiltration with infiltration time were well described by a power function and the Kostiakov model,respectively. During evaporation,the material promoted evaporation at the mid-stage but demonstrated moisture retention at low incorporation rates at the later stage. Pot experiments further verified that under water stress, the material enhanced chlorophyll content in ryegrass, reduced soil compaction, and improved plant drought resistance. Environmental safety assessment indicated that the heavy metal content and leaching toxicity of the material were below the relevant national standard limits. Comprehensive analysis suggests that the coal gangue-based porous material achieves optimal water retention performance at an incorporation rate of 25%,demonstrating considerable potential for application in the ecological restoration of mining areas. The findings clarify the mechanism by which the porous material influences water movement and reveal the structure-function relationship between soil pore characteristics and hydrological processes,providing a scientific basis for water conservation and reclamation practices in mining regions.
下载: