Luo Youfa, Xing Rongrong, Wan Zuyan, Chen Yulu
Key Laboratory of Kast Georesources and Environment, Ministry of Education, Guizhou University, Guiyang 550025, China; Guizhou Karst Environmental Ecosystems Observation and Research Station, Ministry of Education, Guizhou University, Guiyang 550025, China; Guizhou Hostile Environment Ecological Restoration Technology Engineering Research Centre, Guizhou University, Guiyang 550025, China.
College of Resource and Environmental Engineering, Guizhou University, Guiyang 550025, China.
Sci Total Environ. 2023 Jun 25;879:163206. doi: 10.1016/j.scitotenv.2023.163206. Epub 2023 Apr 1.
Direct revegetation is an important measure to immobilize heavy metals and improve the microecological properties of metal smelting slag sites. However, the vertical distribution of nutrients, microecological properties, and heavy metals at a directly revegetated metal smelting slag site remains unclear. Here, the distribution characteristics of nutrients, enzyme activities, microbial properties, and heavy metals in the vertical profile at a zinc smelting slag site directly revegetated with two herb species (Lolium perenne and Trifolium repens) for 5 years were investigated. The results showed that the nutrient contents, enzyme activities, and microbial properties decreased with increasing slag depth after revegetation with the two herb species. The nutrient contents, enzyme activities, and microbial properties of the surface slag revegetated with Trifolium repens were better than those in the surface slag revegetated with Lolium perenne The higher root activity in the surface slag (0-30 cm) resulted in relatively higher contents of pseudo-total and available heavy metals in the surface slag. Moreover, the contents of pseudo-total heavy metals (except for Zn) and available heavy metals in the slag revegetated with Trifolium repens were lower than those in the slag revegetated with Lolium perenne at most slag depths. Overall, the greater phytoremediation efficiency of the two herb species occurred mainly in the surface slag (0-30 cm), and the phytoremediation efficiency of Trifolium repens was higher than that of Lolium perenne. The findings are beneficial for understanding the phytoremediation efficiency of direct revegetation strategies for metal smelting slag sites.
直接植被恢复是固定重金属和改善金属冶炼渣场微生态特性的重要措施。然而，在直接植被恢复的金属冶炼渣场中，养分、微生态特性和重金属的垂直分布仍不清楚。在此，研究了用两种草本植物（多年生黑麦草和白三叶草）对锌冶炼渣场进行5年直接植被恢复后，垂直剖面中养分、酶活性、微生物特性和重金属的分布特征。结果表明，用这两种草本植物进行植被恢复后，养分含量、酶活性和微生物特性随渣层深度增加而降低。白三叶草植被恢复的表层渣的养分含量、酶活性和微生物特性优于多年生黑麦草植被恢复的表层渣。表层渣（0-30厘米）较高的根系活性导致表层渣中伪全量和有效重金属含量相对较高。此外，在大多数渣层深度，白三叶草植被恢复的渣中伪全量重金属（锌除外）和有效重金属含量低于多年生黑麦草植被恢复的渣。总体而言，这两种草本植物的植物修复效率较高主要发生在表层渣（0-30厘米），且白三叶草的植物修复效率高于多年生黑麦草。这些发现有助于了解金属冶炼渣场直接植被恢复策略的植物修复效率。
