污泥施用下园林植物生长适应性和重金属吸收

【目的】分析污泥施用下园林植物单种和混种的生长适应性以及对重金属的吸收积累，为污泥资源化利用和重金属修复的园林植物组合筛选提供理论依据。【方法】以园林树木秋枫Bischofia javanica、园林地被植物山菅兰Dianella ensifolia、合果芋Syngonium podophyllum和鹅掌柴Schefflera odorata为供试植物，以不种植物为对照，设置4种植物单种、秋枫分别与3种地被植物混种共7个处理，开展6个月的污泥添加盆栽试验，分析植物干生物量、根系活力、根系抗氧化酶活性、根系形态、植物重金属积累量和土壤重金属形态变化。【结果】与秋枫单种相比，混种合果芋显著降低了秋枫干生物量、根系超氧化物歧化酶(Superoxidase dismutase,SOD)活性和根系活力；与鹅掌柴混种则显著提高了秋枫根系总根长、总表面积、根体积、比根长以及根系过氧化物酶(Peroxidase,POD)和过氧化氢酶(Catalase,CAT)活性。与秋枫混种的合果芋干生物量、根体积和根系CAT活性显著高于合果芋单种。与秋枫单种相比，混种山菅兰的秋枫Cd积累量提高了238.73%，混种...

Plant adaptability and heavy metals accumulation of different landscape plants in soil applied with sewage sludge

Objective This study aimed to explore plant adaptability and heavy metals accumulation of different landscape plants and the co-planting system in sludge-amended landscape soil and provide a theoretical basis for the sewage sludge landscape utilization and the selection of landscape plants for heavy metals remediation.Method Landscape tree Bischofia javanica and landscape ground cover plant Dianella ensifolia, Syngonium podophyllum, and Schefflera odorata were selected as tested plants. The greenhouse pot experiment contained seven treatments, including four kinds of plant species monoculture, and co-planting of B. javanica with three kinds of landscape ground cover plant, respectively. In addition, substrate without planting was designated as control (CK). The seedlings were harvested after six months. Plant dry biomass, root activity, root antioxidative enzyme activity, root morphology, plant heavy metals accumulation, and the fraction changes of soil heavy metals were analyzed.Result Compared with monoculture treatment, the treatment co-planting with S. podophyllumt significantly reduced the dry biomass, root superoxidase dismutase (SOD) activity and root activity of B. javanica. In contrast, the treatment co-planting with S. odorata significantly increased the total root length, total surface area, root volume, specific root length, root peroxidase (POD) and catalase (CAT) activities of B. javanica. The treatment co-planting with B. javanica significantly increased the dry biomass, root total volume, and root CAT activity of S. podophyllum. Compared with monoculture treatment, the treatment co-planting with D. ensifolia increased the Cd accumulation of B. javanica by 238.73%. The treatment co-planting with S. odorata increased the Cd, Cu, and Ni accumulation of B. javanica by 278.76%, 53.68%, and 71.44%, respectively. The treatment co-planting with B. javanica increased the Cd, Cu, Zn, and Ni accumulation of S. podophyllum by 161.61%, 139.77%, 78.37%, and 65.70%, respectively. Also, the exchangeable and Fe-Mn oxides fractions of Cd were significantly reduced but the residual fractions of Cd, Cu, and Ni were significantly increased by co-planting of B. javanica and S. podophyllum.Conclusion Compared with monoculture treatment, co-planting of B. javanica with S. odorata and co-planting of B. javanica with S. podophyllum increased the accumulation of heavy metals in sludge-amended landscape soils.