含油污水灌区土壤污染特征研究

Soil Properties and Pollution Status in Oily Sewage Irrigation Area

为了研究含油污水灌区土壤污染特征,以TPH为研究对象,对污灌区土壤中TPH的空间分布特征进行探究,并考察污灌引起的TPH污染对土壤基本理化性质的影响。结果表明,污灌引起土壤中油-盐复合污染,污灌区土壤TPH含量显著高于对照组,变化范围为120.01~578.32 mg kg^(-1);各监测单元差异性显著,说明长期污灌会造成不同程度的石油烃污染,TPH含量随采样深度增加而降低,表层土0~20 cm是石油烃的主要累积层位,污染物在剖面上的分布与土壤粘粒含量及有机质有关;污灌区土壤中含盐量为1.25~6.57 g kg^(-1),显著高于对照组,只有约3%的样品属于轻度盐化,约36%的样品属于中度盐化,近61%属于强度盐化,污灌土壤油-盐复合污染特征明显;与对照组相比,pH与氨态氮变化不显著,电导率、有机质、速效磷显著升高,C/N、C/P比例失衡。

In order to study the characteristics of soil pollution by oily sewage, the spatial distribution characteristics of TPH in sewage irrigated area were investigated, and the effect of TPH pollution on soil physical and chemical properties was investigated. The results showed that the pollution of oil and salt in the soil was caused by the sewage irrigation. TPH content in polluted irrigated area was significantly higher than that in control group, with variation range of 120.01-578.32 mg kg^-1. The monitoring units showed significant difference, indicating that long-term sewage irrigation could cause different levels of petroleum hydrocarbon pollution. The content of TPH decreased with the increase of sampling depth. The surface soil（0-20 cm） was the main accumulation layer of petroleum hydrocarbons. The distribution of pollutants on the profile was related to the contents of soil clay and organic matter.The soil salinity in the sewage irrigation area was 1.25-6.57 g kg^-1, which was significantly higher than that in the control group. Only about 3% of the samples belonged to mild salinization, about 36% moderate salinization, and nearly 61% intensity salinization. Compared with the control group, the change of pH and ammonia nitrogen was not significant, the electrical conductivity, organic matter and available phosphorus increased significantly, and the proportion of C/N and C/P was unbalance.