毛竹、银杏凋落叶对酸雨缓冲作用的研究

Buffer action of deciduous leaves of Phyllostachys heterocycla and Ginkgo biloba on acid rain

以浙江省常见树种毛竹(Phyllostachys pubescens)和银杏(Ginkgo biloba)的凋落叶作为研究对象,在pH 2.5、4.0、5.6模拟酸雨梯度下,分别对凋落叶进行淋洗及浸泡处理,研究不同处理方式下凋落叶对酸雨缓冲能力的差异。结果表明:不同处理方式下凋落叶均表现出酸缓冲能力;浸泡处理比淋洗处理凋落叶对酸雨的缓冲效果明显。在pH 5.6处理下,毛竹和银杏的凋落叶浸泡液与淋洗液差异不显著。在pH 4.0处理下,毛竹凋落叶浸泡液与淋洗液差异不显著,但银杏凋落叶浸泡液与淋洗液差异显著。在重酸条件(pH 2.5)下,尽管凋落叶对酸缓冲的效果不明显,但不同处理方式差异显著。因此,可推测凋落叶与酸发生充分反应,从而提高酸液pH。

Deciduous leaves of P. heterocycla and G. biloba （common tree species in Zhejiang Prov- ince） were used as test materials and their soaking and leaching experiments were carried out in simu- lated acid rains respectively at pH 2.5,4.0 and 5.6 to study their buffer action on acid rain. The re- sults showed that the deciduous leaves had a buffer action on the acid rain and the buffer action was more obvious in the soaking experiment than in the leaching one. At pH 5.6 both leacheate and soak of both tree species＇ leaves were not significantly different. At pH 4.0 both leacheate and soak of P. heterocycla leaves were not significantly different but both leacheate and soak of G. biloba leaves were significantly different. At pH 2.5 both leacheate and soak of both tree species~ leaves were sig- nificantly different though the deciduous leaves had not an obvious buffer action on the acid rain. From the above results it was concluded that the deciduous leaves fully reacted with the acid and thus raised the pH value of the acid liquor.