Water And Salt Migration Mechanism And Study On Reclamation Effect In Reclaimed Land By Filling Gangue

Reclaimed land by filling gangue of zhangji coal mine in Huainan city was researched.The soil physical properties and chemical properties and crop growth information were studied.Heavy metal content of soil and crop was researched. Soil column model was founded to simulate the soil water and salt migration rule under the condition of capillary rise and rainfall and evaporation. The best reclamation mode of filling reclamation with gangue was explored. Soil and crop safety was estimated. The change law of soil water and salt was explored. Theoretical foundation of reclamation engineering were provided. It turned out that soil fertility of plots of land reclamation was less than the control block.70-80cm was the greatest thickness of cover soil.The quality of land reclamation and wheat samples were explored by Nemerow multifactor index method.10samples were monitored. Eight samples belonged to the class level Ⅰ.One sample belonged to the class level Ⅱ.One sample belonged to the class level Ⅲ.10samples were monitored.1sample was in middle level pollution levels. Four samples were mild concentration.Two samples belonged to the cleaning level.3samples were completely clean.Cu、Zn、Cd、Cr、As of crop in reclamation area were evaluated by exposure to the health risk assessment method. The risk of exposure index of Cu、Zn、As were less than1.They were in the security level. The risk of exposure index of Cd、Cr were more than1.There were health risk.Three different column model was established. Thickness of mulching soil was45,65,85cm.Soil column capillary water rise maximum height was47.00,46.37,44.81cm.Crop growth was limited. Soil water potential of three soil column decreased with rainfall time when it rained. The change of water potential was delayed. Changes of water potential of every soil column was same in the process of evaporation. Soil water potential increased slowly ten days ago. Soil water potential increased rapidly after ten days. Soil salt had a cumulative effect under the condition of capillary rise and rainfall. The position of salt accumulation related to the capillary water rising height. Soil salt had upward migration phenomenon under the condition of evaporation.