再生水灌溉冬小麦的铅和镉累积分布研究

Heavy Metal Pb and Cd Distribution in Winter-wheat with Reclaimed Water Irrigation

再生水灌溉对作物重金属含量的影响,是再生水能否安全利用的重要基础问题。通过冬小麦的盆栽试验,研究了再生水灌溉对土壤和冬小麦植株铅、镉含量的影响。结果表明,再生水灌溉对土壤铅、镉含量没有明显的影响,而混灌和轮灌较再生水纯灌可以降低土壤铅含量,但对土壤镉含量没有明显的减低作用。再生水灌溉处理小麦各器官的镉含量分布是根>叶>茎>籽粒,铅含量分布是叶>根>茎>籽粒,叶片铅含量较其他器官高可能与大气铅污染有关。再生水灌溉后,小麦各器官镉含量较清水对照有一定的提高,但铅、镉含量和对照相比差异不显著。应用再生水灌溉,小麦籽粒中铅、镉含量均符合国家食用安全标准,但镉含量较清水灌溉有升高现象,在生产应用中要有所注意。

The effect of reclaimed water irrigation on crops metal accumulation is a crucial issue for sewage water safely utilization on agriculture.The research studied heavy metal Pb and Cd content and distribution in soil and winter wheat under reclaimed water irrigation by using pot planting trails.The results showed that there was no significant difference in soil Pb,Cd content with reclaimed water irrigation compared with fresh water control treatment.Meanwhile,mixed and alternative irrigation of reclaimed water and fresh water could little reduce Cd and Pb soil content compare with purely using reclaimed water.Cd content order in different organ of winter wheat was root leaf stem grain,and it had somewhat increase compared with fresh water treatment.The Pb content order in different organ of winter wheat was leaf root stem grain,the higher Pb content in leaves was likely related with air pollution of experiment trail site.Both Pb and Cd content in different organ had no significant difference between reclaimed water irrigation and fresh water treatment.The Pb and Cd content in grains were lower than National Restriction of Pb and Cd content for food consumption,but Cd content was little higher with reclaimed water irrigation than fresh water which should be noticed in field practice.