Study On Influence Characteristics Of Temperature Field And Reclamation Effect By Filling Coal Gangue Substrate

For studying the characteristics of temperature field under the influence of weathering process and the effect of reclamation plots by filling coal gangue,different types reclamation land were constructed as the research area,soil moisture monitoring base station was established and high precision temperature and humidity sensors were embed on different layers in each plots.Dynamic monitoring the soil temperature and moisture of the reconstructed soil on vertical and horizontal gradient,the change mechanism of temperature field and the water spatial distribution were analyzed,the heat transfer model is established by using the mathematical method.Through the physical and chemical properties of soil,physiological and ecological characteristics and heavy metal content of the crop were measured,the quality of reclamation plots was evaluated,and the crop safety was analyzed,the spatial distribution of pollutants in crops and accumulation characteristics,to further determine the best effect of reclamation of coal gangue particles and the greatest thickness of cover soil.Experimental results show that:(1)The coal gangue will release heat in the process of physical and chemical reactions with water and atmosphere,the internal temperature of coal gangue as fill substrates is also constantly accumulating.The change of temperature field which has used coarse coal gangue as filling substrate was the most intense;with the analysis of soil temperature and moisture data,there was significant correlation between the soil temperature and moisture in the reclamation plots.In a certain temperature range,the soil moisture increased with the increase of temperature,exceed the limit value,soil moisture decreases with the increase of the soil temperature.(2)The water content and available nutrients in six kinds of reclamation plots were lower than undisturbed plots.As the filling substrate,it is difficult to release the available nutrients of coal gangue.Considering the comprehensive index of soil quality,the height of wheat plant height,the yield and the ecological and environmental benefits of the reclamation project,the results show that the soil thickness of the coal gangue reclamation site is 50cm,which can meet the crop growth demand;Coal gangue particle size in the medium coarse ratio is more reasonable.(3)As,Cu,Zn,Cd content in wheat grain of six kinds reclamation plots in safe level,were lower than the heavy metal concentration limit values.In addition to the Cr content in wheat grains of the VI reclamation plot less than 1.Omg/kg,the Cr content of wheat grains in the other reclamation plots exceeded the standard,and the maximum value was 1.83 times higher than the standard value.The enrichment degree of heavy metals in wheat grains was lower than that of other organs,and As,Cu,Pb,Zn,Cd,Cr enrichment characteristics were higher than those in other organs.