陕北石油区城市绿化树木枯落叶对油污土壤的修复效应

为了修复石油污染土壤和资源化利用城市绿化树木枯落叶,采集陕北典型石油污染土壤,施入19种常见城市绿化树木枯落叶粉碎样进行为期120 d的室内混合分解培养试验,检测不同枯落叶修复土壤化学和生物学性质及降解石油烃的能力,并以主成分分析法进行综合评价。结果表明:对油污土壤性质综合修复效应最好的是苦楝(Melia azedarach)和桃树(Prunus persica)枯落叶,较好的依次为桑树(Morus alba)、国槐(Sophora japonica)、垂柳(Salix babylonica)、五角枫(Acermono Maxim)和紫叶李(Prunus cerasifera)枯落叶,其他树木枯落叶效果不明显,有的甚至起到恶化作用。

Remediation Effects of Urban Greening-Tree Litters on Petroleum-Contaminated Soil in Oil Producing Region of Northern Shaanxi

Soil contamination by petroleum has become a serious environmental issue in oil-producing areas. Research has showed that organic residue additions could enhance the degradation of petroleum in soils. In a laboratory experiment, the effects of litters from 19 urban greening tree species on chemical and biological properties of petroleum-contaminated soil were evaluated. A petroleum contaminated soil was collected in Northern Shaanxi and incubated with the litters for 120 d. Additions of all foliar litters significantly increased the contents of organic matters, available K and available Zn in the contaminated soil. Most of litters significantly increased the contents of alkaline-soluble N and available Mn and Fe, and enhanced the activities of catalase, sucrose, phosphatase, dehydrogenase, urease and protease. Applying the litters also promoted the growth of fungi and actinomycetes. However, litter applications generally decreased soil pH values but did not increase available P and Cu contents. In the tested 19 litters, only several litters improved bacterial population and polyphenol oxidase activity. Except Acer mono, all tree litters accelerated petroleum degradation. Such effect was in order of Melia azedarach > Prunus persica > Morus alba > Sophora japonica > Salix babylonica > Acermono Maxim > Prunus cerasifera. The litters from the rest species had negligible or even negative effects on petroleum degradation.