地膜中邻苯二甲酸酯类化合物及重金属对土壤-大豆的污染

Pollution by phthalic acid esters and heavy metals in plastic film in soil-soybean system

采用盆栽实验研究了大豆各生育时期,不同地膜残留量土壤和植株中邻苯二甲酸二丁酯(DBP)、邻苯二甲酸二(2-乙基已基)酯(DEHP)、重金属Pb、Cd含量及大豆生长发育、品质的差异性。结果表明,大豆各生育时期,高倍地膜残留量土壤和植株中DBP、DEHP含量高于低倍残留量,差异达到显著水平。CK处理土壤中DBP和DEHP含量随着生育周期延长显著降低,而1倍、3倍和5倍地膜残留量则呈增加趋势,各处理DBP和DEHP与生育时期呈一定线性相关关系。按照美国土壤中PAEs的控制标准,除CK处理土壤中DBP和DEHP含量及1倍处理土壤中DEHP含量未超标外,其余各处理均不同程度地超标,DBP超标倍数较大,最高超标6.4倍,DEHP超标倍数较小。DBP和DEHP含量均低于美国土壤中PAEs的治理标准。植株中未检测出DEHP。各生育时期,高倍地膜残留量土壤中Pb、Cd含量均高于低倍残留量。大豆籽粒中重金属Pb、Cd含量低于《食品中污染物限量》标准,在盆栽条件下,大豆籽粒中重金属含量是安全的。各处理对大豆生长发育、水分、蛋白质、脂肪含量影响差异不明显。

A pot experiment was conducted to study the different contents of dibutyl phthalate （DBP）, ethylhexyl phthalate （DEHP）, Pb, Cd, soybean growth and quality in soil and plants in the growth periods with different residual amount of mulching plastic film. According to the experiment, the contents of DBP and DEHP in high residual mulching film samples are higher than in low ones and the difference is obvious. In the soil treated with CK, the contents of DBP and DEHP decline obviously along the plants＇ growth, hut the contents climb up in 1-times, 3-times and 5-times residual amount of mulching plastic film. DBP and DEHP contents are in linear relationship in the result with different periods. According to the PAEs control limits of USA, the contents of DBP and DEHP are not exceeded except CK processing soil samples and the content of DEHP in 1-times processing soil sample. The content of DBP is several times over the stan- dard and the highest one exceeds 6.4 times and DEHP is few times over standard. The contents of DBP and DEHP are lower than the PAEs （USA） standards. The DEHP is not discovered in the plants. In every growth period the contents of Pb and Cd are higher in high residual mulching film than in lower ones. The content of Pb and Cd in soybean seed is far lower than the standard of ＂food contamination standard＂ and the heavy metal content is safe in soybean seed with potted conditions. The contents of growth, water, Cd, protein and fat are not sifnificant with differentky residual mulching film.