改良剂与油菜对土壤重金属有效态的影响

The Influence of Amendments and Rape on Available Heavy Metals Content in Soil

通过连续三季盆栽试验,研究利用粉煤灰、膨润土、腐殖酸3种改良剂特性及油菜的富集作用强化修复效果,阐明改良剂与油菜对土壤重金属有效态的影响。油菜收获后测定土壤重金属有效态浓度。结果表明,粉煤灰浓度为12,18g/kg时,可明显降低第1季土壤Cd有效态浓度,但对土壤有效态Cu、Zn浓度未产生明显影响,第2季浓度为6g/kg及第3季各处理可明显降低Pb有效态浓度。粉煤灰降低Cd有效态第1季效果较好,降低Pb有效态浓度第3季效果较好。只有当膨润土浓度为18g/kg时可明显降低第1季土壤Cd有效态浓度,第2季浓度为18g/kg和第2,3季浓度为6g/kg时,可降低土壤Cu有效态浓度,第2季浓度为12,18g/kg及第3季所有处理均可有效抑制Pb的活性,对Zn活性未表现出明显的抑制作用。膨润土降低土壤Cd有效态浓度的第1季效果较好,降低Cu、Pb有效态浓度第2,3季效果较好。腐殖酸浓度为2,3g/kg时可降低第2季有效态Cd浓度,第2季浓度为3g/kg及第3季浓度为2,3g/kg时土壤Cu有效态浓度明显降低,第2季浓度为3g/kg及第3季所有处理可降低Pb有效态浓度,而腐殖酸对Zn活性未起到明显的抑制作用。腐殖酸降低土壤Cd有效态浓度第2季效果较好,降低Cu、Pb有效态浓度效果第3季效果较好。3种改良剂对吸附、固定Cd、Pb、Cu、Zn的作用程度不同,粉煤灰降低土壤Cu有效态浓度、3种改良剂降低土壤Zn有效态浓度的效果不理想。因此,在生产实践中,根据实际情况适时、适量施入改良剂,可降低重金属对生产、环境带来的危害。

Based on current situation of heavy metals contamination in China, a 3-season experiment was carried out in greenhouse to evaluate the potential of coal fly ash, bentonite, and humic acid added to the soil with Cd, Pb, Cu, and Zn on inhibiting availability of these heavy metals in soil. The concentrations of available Cd, Pb, Cu and Zn in soil with application amendments were determined after rape harvest. The treatments were arranged： 0（control） as three amendments, 6, 12, 18 g/kg as coal fly ash and bentonite, and 1, 2, 3 g/kg as humic acid. Results showed that coal fly ash markedly inhibited the mobility of Cd in soil at 12, 18 g/kg in the first season, did not clear effect on decreasing available Cu and Zn content, and reduced Pb mobility at 6 g/kg in the second season and at all treatments in the third season. For bentonite, only addition of 18 g/kg bentonite significantly reduced available content of Cd in the first season, the doses of 6, 18 g/kg in the second season and the doses of 6 g/kg in the third season reduced the content of available Cu significantly, the doses of 12, 18 g/kg in the second season and all treatments in the experiment inhibited Pb mobility effectively, and all dosages could not decrease available Zn content significantly in the experiment. For humic acid, the mobility of Cd was inhibited at 2, 3 g/kg only in the second season, available Cu concentration was affected effectively at 3 g/kg in the second season and at 2, 3 g/kg in the third season, the available Pb contents reduced effectively at 3 g/kg in the second season and at all treatments in the third season, and the immobilizing Cd available Zn c , Pb, Cu and ontent could not Zn were different be reduced in the experiment. The effect of amendments on from each other, so in practice, these amendments should be input into soil according to their characteristics in proper time in order that they could absorb heavy metals in soil completely.