离子交换纤维对麦田土壤铅污染的修复效果

为探讨土壤Pb污染的治理方法,通过盆栽试验,比较了离子交换纤维的两种不同放置方式(分层放置与混匀放置)对麦田土壤Pb污染的修复效果。结果表明,在土壤1 000 mg·kg~(-1) Pb污染水平下,Pb污染处理(T1:Pb胁迫;T2:Pb+在土壤中分三层放置纤维;T3:Pb+在土壤中混匀剪碎的纤维)的土壤pH值、总有机碳含量较对照(CK:未添加Pb和离子交换纤维)有所降低。在小麦成熟期,T2、T3处理下土壤和植株各部位的Pb含量均低于T1处理,其中T3处理变化显著;T2、T3处理中纤维吸附的Pb含量则分别达到115.01和128.26 mg·kg~(-1)。T2、T3处理的Pb富集系数低于T1处理及CK。由此说明,离子交换纤维能够有效吸附土壤中的Pb,降低Pb从土壤向植株的转运能力,且离子交换纤维混匀放置方式的修复效果较好。

Remediation Effect of Ion-Exchange Fiber on Lead Pollution in Wheat Field

In order to repair the Pb pollution in wheat field soil, a experiment was conducted to investigate the effects of two kinds of placement methods of ion-exchange fibers:placed in three layers and mixed evenly with soil. The results showed that soil pH and total organic carbon(TOC) content of three Pb pollution treatments(including T1:Pb stress, T2:Pb stress and ion-exchange fibers placed in three layers in the soil, T3:Pb stress and ion-exchange fibers mixed evenly with soil) were all lower than those of the control(CK) at the Pb pollution level of 1 000 mg·kg^-1. In the maturity stage of wheat, Pb content of soil under T2 and T3 were 1.36 mg·kg^-1and 18.52 mg·kg^-1, respectively, lower than that under T1. Pb content in plants under T2 and T3 was also lower than that under T1. In the other hand, the Pb content adsorbed by the ion-exchange fibers under T2 and T3 reached to 115.01 mg·kg^-1and 128.26 mg·kg^-1, respectively. According to the calculation, the enrichment coefficients of Pb under T2 and T3 were all lower than those under T1 and CK without fibers. In short, the ion-exchange fibers effectively adsorbed Pb in soil and reduced the transfer capacity of Pb from soil to plants. In addition, in terms of the placement of ion-exchange fibers, the adsorption capacity of Pb under T3 is higher than that under T2. The remediation effect of ion-exchange fibers mixed placement is better than that of the layer placement.