不同复垦年限煤矸山土壤重金属有效态含量及其影响因素分析

Available heavy metal content and its influence factors in soil of gangue hill with different reclamation years

研究煤矸山不同年限复垦土壤重金属有效态含量及其影响因素对指导煤矸山植被复垦及复垦地利用具有重要意义。以山西省典型煤矸山复垦3、10、16年灌草地为研究对象,分析了3种复垦土样的理化性质及重金属Cd、Pb、Cu的总量、有效态含量、生物有效性系数。结果表明:(1)3种复垦土样电导率(EC)、有机质和碱解氮含量均随复垦年限的增加而增加,但黏粒和有效磷含量呈下降趋势;(2)总体看来,3种复垦土样Cd、Pb、Cu有效态含量随复垦年限的增加而增加,Cd、Pb生物有效性系数在0~40cm土层、Cu生物有效性系数在20~40cm土层也有此趋势;(3)土壤pH、EC、有机质、黏粒质量分数均不同程度地影响煤矸山复垦土壤Cd、Pb、Cu有效态含量,其中有机质和黏粒含量是关键影响因子。

The investigation of available heavy metals in reclamation soil of gangue hill with different years as well as the influencing factors was of great importance to the plant reclamation and utilization of gangue hill.The grasslands reclaimed for 3,10 and 16 years were collected in typical gangue hill of Shanxi,and the physical and chemical characteristics,total heavy metal content,available heavy metal content and bioavailability coefficient of the 3 reclaimed soil samples were analyzed.The results showed that:(1)electrical conductivity(EC),organic matter and alkali-hydrolyzable nitrogen content in 3 reclamation soil samples were increased with the increasing of reclamation time,but clay and phosphorus content decreased by years;(2)the available contents of Cd,Pb and Cu in the 3 reclaimed samples increased with the increasing reclamation years,and the bioavailability coefficients of Cd and Pb in the 0-40 cm soil layers,the Cu bioavailability coefficient in 20-40 cm soil layers presented the same tendency;(3)the soil pH,EC,organic matter content,clay content affecting the available heavy metals content in the reclamation soil in different degree,and organic matter and clay content were the main influencing factors.