珠三角城市群典型城市土壤邻苯二甲酸酯污染特征

Characteristics of pathalic acid esters in soils in typical cities of Pearl River Delta

选择了经济相对发达的珠江三角洲城市群中的典型中小城市的菜园和果园表层土壤(0～20cm)进行调查取样,采用气相色谱法,对土壤样品中的16种邻苯二甲酸酯(PAEs)进行了测定,分析了其分布特征,并初步探讨了本区域的PAEs的污染控制问题。结果表明:在珠三角城市中,东莞土壤的PAEs含量最高,各地土壤中的PAEs均值高低顺序依次为东莞>深圳(珠海)>中山(惠州);菜园土壤中的平均PAEs含量比果园高37%左右;从珠三角城市菜地和果园的平均PAEs分布来看,东莞和深圳的菜地PAEs明显高于果园;珠海、中山和惠州菜地的平均PAEs与果园基本持平。16种PAEs类化合物在珠江三角洲不同城市的分布的差异非常大,不同城市所受到的主要PAEs化合物污染的种类不同;与美国土壤PAEs控制标准相比,珠三角城市果园和菜地土壤的PAEs主要为DEP和DnBP超标,这两类PAEs化合物应该成为重点的污染控制对象。

PAEs were main plasticizers that can be accumulated in soils and cause potential environmental hazards. Therefore, a detail investigation of the PAEs concentration in the soils in typical cities of Pearl River Delta was made. Surface soil （0-20cm） samples from soils of typical cities in this region were collected, and the concentrations of 16 PAEs were determined by gas chromatography. The results showed that the averaged concentration of PAEs in the soil from Dongguan City was the highest among those from the cities in Pearl River Delta. The mean concentration of PAEs varied with the types of land-use pattern and regions, and decreased in the sequence of Dongguan〉Shenzhen and Zhuhai〉Zhongshan and Huizhou. The averaged concentration of PAEs in vegetable soils was 37% higher than that in orchard garden soils. In Dongguan and Shenzhen, the PAEs had higher concentrations in vegetable soils than in orchard soils, while in Zhuhai, Zhongshan and Huizhou cities, the concentrations of PAEs in these two soils were similar. The distribution patterns of 16 kinds of PAEs in different cities of Pearl River Delta were quite different and it should be noticed that HEP in the soils from Dongguan City was much higher than the other kinds of PAEs. DEP and DnBP concentrations in vegetable and orchard soils exceeded the PAEs standard set for USA soils, indicating that these two compounds should be the main pollutants in PRD regions to be controlled.