三叶草和黑麦草修复对炼锌废渣剖面养分及重金属分布特征的影响

为评价两种草本植物修复5年后的土法炼锌废渣剖面上养分及重金属分布特征，以废渣堆场上人工种植的三叶草（Trifolium repens）和黑麦草（Lolium perenne）为研究对象，分析两种草本植物剖面（0~60 cm）上不同粒径废渣中养分和重金属的分布特征.结果表明：随着废渣剖面深度增加，废渣中全氮、碱解氮、全磷、有效磷含量逐渐降低，表层废渣（0~10 cm）中有机质含量大多显著（p<0.05）低于深层废渣（10~60 cm）；而表层废渣（0~20 cm）的有效态氮磷含量大多显著（p<0.05）高于深层废渣（20~60 cm）.有机质和全氮含量随着废渣粒径增大呈先增加后降低的趋势，其含量在粒径为0.25~0.5 mm的废渣中最高，而碱解氮和有效磷含量则随废渣粒径增大逐渐降低.三叶草修复作用下其剖面不同粒径废渣中有机质、全氮、碱解氮、全磷含量高于黑麦草.As、Cu、Pb、Zn含量随着废渣深度增加呈先降低后增加的趋势，且其在表层废渣（0~20 cm）中的含量高于深层废渣（20~60 cm）.除As外，Cd、Cu、Pb、Zn的含量总体表现为随废渣粒径增大而降低.两种植物修复作用下，酸可交换态As、Cd、Cu、Zn占比均随废渣剖面深度增加而增加，酸可交换态Cd、Cu、Pb、Zn占比均随废渣粒径增大而增加.综上，三叶草和黑麦草参与下垂直剖面上不同粒径废渣养分及重金属含量分布特征具有明显的差异.

Effect of Trifolium repens and Lolium perenne restoration on distribution characteristics of nutrient and heavy metals in zinc smelting slag profiles

In order to evaluate the distribution characteristics of nutrient and heavy metals in indigenous zinc smelting slag profiles after 5 years of two herbs restoration, Trifolium repens and Lolium perenne cultivated in zinc smelting slag were studied, and the distribution characteristics of nutrient and heavy metals in slag of different sizes in profiles (0~60 cm) of two herbs were analyzed. The results showed that the content of total nitrogen, hydrolysis nitrogen, total phosphorus and available phosphorus decreased as the depth of slag increased. The content of organic matter in surface slag (0~10 cm) were significantly lower than in bottom slag (10~60 cm); and the content of available nitrogen and phosphorus in surface slag (0~20 cm) were significantly higher than in bottom slag (20~60 cm). The content of organic matter and total nitrogen in slag increased firstly and decreased at last with the increasing particle size, and the highest content was 0.25~0.5 mm, and the content of hydrolysis nitrogen and available phosphorus in slag decreased with the increasing particle size. The content of organic matter, total nitrogen, hydrolysis nitrogen and total phosphorus in the slag with different particle size in the profile under the Trifolium repens restoration is higher than Lolium perenne. The content of As, Cu, Pb, and Zn decreased firstly and then increased with the increased of slag depth, and its contents in surface slag (0~20 cm) were higher than in bottom slag (20~60 cm). Additionally, the content of As, Cd, Cu, Pb, and Zn in slag decreased with increasing particle size. The proportion of acid exchangeable As, Cd, Cu, and Zn in slag increased as the depth of slag increased, the proportion of acid exchangeable Cd, Cu, Pb, and Zn in slag increased with the increasing of particle size. In conclusion, the content of nutrient and heavy metals in slag of different sizes in the vertical profile have obvious spatial differentiation under the influence of Trifolium repens and Lolium perenne.