CRETUS Institute, Departamento de Edafoloxía e Química Agrícola, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Spain.
Int J Environ Res Public Health. 2020 Apr 22;17(8):2887. doi: 10.3390/ijerph17082887.
Interest in using urban waste composts as amendments in urban agriculture is growing nowadays. However, concerns about the potential transference of pollutants present in urban waste to the food chain are very relevant when they are recycled for food or animal feed production. Thus, for the safe use of urban waste composts, it has to be assured that no risk of metal transference to plants from compost exists. In this work, the transference of heavy metals from urban waste composts to plants has been studied in an experiment with lettuce and Italian ryegrass, grown in substrates based on five metal-rich composts and a manure vermicompost (included for comparison). A two-month pot experiment was performed under controlled light and temperature conditions, and plant growth and uptake of Cu, Pb, Cd and Zn were analyzed. For both species, the concentration of metals in plant tissue followed the sequence Zn > Cu >> Pb ≈ Cd, the same as the metal concentrations in four out of the five composts. Plant concentrations of Zn, Cu and Cd increased with their concentrations in compost, whereas this relation was not observed for Pb. The ratio between element concentration in plant and compost were much higher for Zn, Cd and Cu than for Pb, showing the lower bioavailability of Pb with respect to other metals.
现如今，人们对将城市垃圾制成堆肥用作城市农业改良剂越来越感兴趣。然而，当城市垃圾被回收用于食品或动物饲料生产时，其中存在的污染物是否有可能转移到食物链，这是一个非常值得关注的问题。因此，为了安全使用城市垃圾堆肥，必须确保堆肥中的重金属不会转移到植物中。在这项工作中，研究了在生菜和黑麦草的实验中，重金属从城市垃圾堆肥转移到植物的情况，实验中使用的基质基于五种富含金属的堆肥和一种粪肥蚯蚓堆肥（包括进行比较）。在受控的光照和温度条件下进行了为期两个月的盆栽实验，分析了植物生长和对 Cu、Pb、Cd 和 Zn 的吸收。对于这两个物种，植物组织中金属的浓度顺序为 Zn > Cu >> Pb ≈ Cd，与五种堆肥中的四种金属浓度相同。对于 Zn、Cu 和 Cd，植物浓度随着堆肥浓度的增加而增加，而对于 Pb 则没有观察到这种关系。元素在植物和堆肥中的浓度比值对于 Zn、Cd 和 Cu 远高于 Pb，表明 Pb 的生物可利用性相对于其他金属较低。
