鸟粪对同里湿地公园土壤重金属及其形态的影响

为了解鸟粪对同里湿地公园土壤重金属全量及形态转化的影响,测定了公园内有鸟粪土壤、无鸟粪土壤、鸟粪沉积物的理化性质,Co、Cr、Cu、Ni、Zn全量及其形态分布,并进行统计分析。结果显示:同里湿地公园土壤及沉积物p H值平均含量达4.5,N、C、H、S和TP平均含量分别达到3.69、38.07、10.97、0.52、1.43g/kg,有鸟粪土壤中N、C、H和S含量显著高于无鸟粪土壤。Cu、Zn、Co平均含量呈现出鸟粪沉积物有鸟粪土壤无鸟粪土壤;Cr的平均含量表现为鸟粪沉积物无鸟粪土壤有鸟粪土壤;Ni呈现出有鸟粪土壤鸟粪沉积物无鸟粪土壤。总体上,鸟粪的进入增加了土壤Cu、Zn、Co、Ni含量。因此应及时清理土壤上覆鸟粪,降低对当地重金属污染风险。相对于无鸟粪土壤中不同重金属形态的分布,有鸟粪土壤中Co、Cr、Cu、Zn的活性态占全量的百分比均略有下降,非活性态呈上升趋势。鸟粪的加入,虽然会在一定程度上降低活性态重金属占总量的比例,但因总量和活性态含量均上升,向植物系统的迁移量会呈现增加趋势,因此对鸟粪施肥再利用应慎重。

Heavy metal concentrations and speciation of soil affected by bird droppings in Tongli Wetland Park, East China

The heavy metal content and speciation in soil and bird droppings from Tongli National Wetland Park were determined. The main purpose was to understand the impact of bird droppings on wetland soil heavy metal contentraions and their speciationchanges. Soil with and without bird droppings was collected from Tongli Wetland. The metal concentrations were determined by inductively coupled plasma-optical emission spectrometry. The result suggested that the average pH for soil was 4.5, and the contents of N, C, H, S, and TP were 3.69, 38.07, 10.97, 0.52, and 1.43g/kg, respectively. Thus, the N, C, H, and S levels in soil containing bird dropping were significantly higher than those in soil without bird droppings. The average contents of Cu, Zn, and Co were in the order guano sediments > soil with bird dropping > soil without bird droppings. The average content of Cr was in the order guano sediments > soil without bird droppings > soil with bird dropping. The average content of Ni was in the order soil with bird droppings > guano sediments > soil without bird droppings. In general, the Cu, Zn, Co, and Ni contents in soil increased with the presence of bird droppings. Bird droppings should be cleaned in a timely manner to reduce the local pollution risk of heavy metals in soil. The percentages of total active Co, Cr, Cu, and Zn fractions in soil containing bird droppings were slightly lower than those in soil without bird droppings. The inactive state showed an upward trend. The proportion of the total activity of heavy metals in soil reduced with the presence of guano, but the content of total and active heavy metals in the soil increased; therefore, the amount of migration of plant systems will increase, and fertilization using bird droppings should be applied carefully.