煤矸石堆存对土壤盐分空间分布特征的影响及主要因子的研究

Effect of coal gangue stockpiling on spatial distribution characteristics and main factors of soil salinity

以潘一矿煤矸石山和周边复垦土壤为研究对象,重点研究煤矸石堆存过程中对周边土壤盐分空间分布特征的影响,并模拟雨水酸度进行煤矸石风化物静态浸泡实验,分析研究影响煤矸石风化物盐分溶解释放的主要因子。结果表明,复垦区土壤的盐分含量均值略高于土壤背景值,水平分布上在煤矸石山周边4 m范围内,土壤的盐分含量受煤矸石山淋溶运移等作用的影响较大,且距离煤矸石山脚处1和2 m处土壤盐分呈轻度盐渍化水平。土壤盐分含量垂直分布特征上,土壤盐分含量均值在垂直方向上呈V字型分布,不同深度土壤的盐分含量均值略高于土壤背景值。研究区土壤盐分组成中阳离子主要为K++Na+,阴离子主要为HCO-3,土壤盐分组成特征以NaHCO3为主,不同深度之间同一盐基离子含量显著性差异不大。煤矸石风化物静态浸泡实验表明,粒度越小,TDS的溶解释放速率越快,浸泡液中盐分含量值越大;不同固液比浸泡液中TDS值变化幅度比较大,呈现出TDS1∶5>TDS1∶3>TDS1∶15>TDS1∶10的变化规律;在不同酸度浸泡下,煤矸石风化物呈现出TDS5.6>TDS6.8>TDS6.0>TDS6.4的变化规律;随着浸泡液温度的逐渐升高,煤矸石风化物粒径越小受温度影响越大。最后,探讨了盐渍化土壤的植物修复技术和防控措施。

This study selected coal gangue piles and reclaimed soil of Panyi coal mine in Huainan as research object,the spatial distribution characteristics of soil salinity were investigated during the stockpiling of coal gangue. Mean while,the simulated rainwater acidity was also determined to test the static immersion. The main factors affecting the dissolution and release of weathered coal gangue were disclosed. The results showed that the average soil salinity con tent was slightly higher than that of soil background value. In the horizontal direction,the soil salinity content was af fected by the leaching and migration of the coal gangue piles in the 4 m range around the coal gangue piles. The soil salinity was at slightly salinization level between the 1 m and 2 m at the foot of coal gangue piles. It shaped as V distri bution in vertical direction and the average salt contents of soil at different depths were slightly higher than background value. The cations were mainly composed of k＋＋Na＋and the anion was mainly HCO-3. The composition of soil salinity was characterized by NaHCO3,and no significant differences were found for the contents of the same ions between dif ferent depths. Static immersion experiment of weathered coal gangue showed that the smaller the size of the particle,the faster the TDS dissolution rate,and the salt content in the solution was higher. The variation of TDS value in the immersion was great at different solid liquid ratios,followed the order of TDS1 ∶ 5〉 TDS1 ∶ 3 〉TDS1 ∶ 15〉 TDS1 ∶ 10. While at different acidities,those values followed the order of TDS5. 6 〉TDS6. 8 〉TDS6. 0 〉TDS6. 4. With the increasing tempera ture of the soaking solution,the smaller the size of the particle it was more influenced by the temperature. Finally,the phytoremediation technology and control measures of soil salinization were discussed. This study provides an important theoretical basis for the ecological reclamation and comprehensive utilization of coal gangue,and also provides an im portant reference for solving the soil environmental problems in similar mining areas.