含砷水滴灌对小白菜砷累积的影响

Effect of Drip Irrigation with Arsenic Water on Arsenic Accumulation in Pakchoi

为探究含砷(As)水滴灌对小白菜中As累积及无机砷赋存形态的影响,通过改变灌溉方式(漫灌、滴灌)、灌溉液中总砷含量或滴灌液中As(Ⅲ)/As(V)的比例等条件,进行了盆栽土培模拟实验。结果表明:滴灌方式下小白菜地上部和根部中总As含量、As(Ⅲ)与As(V)的比例(As(Ⅲ)/As(V)比例)均大于漫灌方式;随着滴灌液中As(Ⅲ)/As(V)比例的增加,小白菜体内总As含量及As(Ⅲ)/As(V)比例均不断增大。与灌灌相比,滴灌方式促进了小白菜中总As的累积,且增加了总As中As(Ⅲ)赋存形态的比例;滴灌液中As(Ⅲ)赋存形态比例的增加促进了小白菜对总As的累积,同样增加了总As中As(Ⅲ)赋存形态的比例。滴灌方式能够造成含砷水灌溉的生态和健康风险放大效应。

In order to explore the effects of arsenic water drip irrigation on As accumulation and inorganic arsenic form in pakchoi,by changing the irrigation methods(flood irrigation,drip irrigation),total arsenic content in the irrigation water,and the ratio of As(Ⅲ)to As(V)in irrigation water,a potted experiment was carried out.The results showed that under the same As contaminated level,the accumulation of total As content and the ratio of As(Ⅲ)to As(V)in pakchoi shoots and pakchoi roots under drip irrigation were far more than those under flood irrigated.The total As content and the ratio of As(Ⅲ)to As(V)in pakchoi increased with the increase of the ratio of As(Ⅲ)to As(V)in the drip irrigation solution.Thus,both the drip irrigation model and the increase of the As(Ⅲ)proportion in the drip irrigation solution promoted the accumulation of total As in pakchoi and the distribution coefficient of As(Ⅲ)form in pakchoi.The ecological and health risk of water arsenic bearing can be amplified by drip irrigation model.