新疆五家渠地区不同覆膜年限棉田土壤中邻苯二甲酸酯残留特征

Residual Characteristics of Phthalate Acid Esters(PAEs)in Cotton Fields with Different Mulching Film Years in Wujiaqu Area,Xinjiang

为探究新疆五家渠地区不同地膜使用年限棉田土壤中邻苯二甲酸酯(PAEs)残留特征,采集五家渠蔡家湖垦区9块不同覆膜年限棉田土壤样品,采用GC-MS对土壤PAEs含量及理化性质进行分析,并对其污染分布和污染程度进行评价。结果显示,不同覆膜年限棉田土壤中6种优先控制的PAEs总量(∑PAEs)范围为1.360~4.490 mg/kg,均值±标准差为(2.770±0.919)mg/kg。不同覆膜年限棉田土壤中PAEs以邻苯二甲酸二(2-乙基己基)酯(DEHP)、邻苯二甲酸二正辛酯(DnOP)为主,其中DEHP占PAEs总量的26.47%~34.97%,DnOP占17.82%~36.49%。参照美国优先控制PAEs化合物的控制标准,100%土壤样品邻苯二甲酸二正丁酯(DBP)含量均超过控制标准,66.67%的土壤样品邻苯二甲酸二乙酯(DEP)含量超过控制标准,表明调查区域土壤存在一定程度PAEs污染风险。随着覆膜年限的增加,PAEs总量并非呈现线性增长趋势,覆膜5年地块土壤PAEs总量最高,显著高于其他各覆膜年限棉田。土壤中PAEs总量与DEP、DBP、DEHP含量存在显著的正相关关系,DnOP含量与土壤含水率存在显著正相关关系,与pH值存在负相关性。

To explore the residual characteristics of phthalate esters(PAEs)in cotton fields with different plastic film service life in Wujiaqu,Xinjiang by collecting 9 soil samples of cotton fields with different film mulching years in Caijiahu Reclamation area of Wujiaqu.The soil PAEs content and physicochemical properties were analyzed by GC-MS,and the pollution distribution and pollution degree were evaluated.The results showed that PAEs content(∑PAEs)in soil of different film mulching years ranged from 1.360 to 4.490 mg/kg and the mean±standard deviation was(2.770±0.919)mg/kg.Diethyl hexyl phthalate(DEHP)and Di-n-octyl phthalate(DnOP)were the main components of PAEs in the soils,accounting for 26.47%-34.97%,and 17.82%-36.49%of the total content of PAEs.Based on the control standards of priority pollutants of PAEs(U.S.EPA),dinbutyl phthalate(DBP)content in all soil samples and diethyl phthalate ester(DEP)in 66.67%soil samples exceeded the control standard,implying that these soils had certain pollution risks.The total content of PAEs content in soils did not show significant correlation with different mulching film years of soil.The total content of PAEs content was the highest in 5year of film mulching cotton soil.The total content of PAEs had a significant positive correlation with DEP,DBP and DEHP;DnOP had a significant positive correlation with soil moisture content,but significantly negatively correlated with pH.