【作者】 袁合金；

【导师】 刘维屏； 张安平；

【作者基本信息】 浙江工业大学 ， 环境工程， 2009， 硕士

【摘要】 历史上,浙江省曾大量使用过已被禁的有机氯农药,如HCH、DDT。直到最近几年,在某些茶区,有机氯农药硫丹仍被大量使用。然而有关浙江省土壤环境中残留有机氯农药的量,很难在公开的文献中查到,这对评估残留有机氯农药的环境安全带来了很大的困难。即使有一些环境介质中有机氯农药的调查,但也只是局限于外消旋的有机氯农药,对于手性有机氯农药的研究是没有的。本研究既在外消旋的基础上调查有机氯的浓度,也在手性的基础上研究其降解情况。结果发现浙江省中有机氯的污染不是很严重,在EF值上研究手性降解,结果发现其EF值基本偏离0.5。浙江省各种有机氯农药的浓度情况是DDTs＞HCHs＞硫丹＞其他分析的痕量有机氯农药,含量情况基本与历史上的使用以及他们的理化性质是项符合的。多数有机氯农药的浓度呈对数正态分布,空间分布趋势显示有机氯农药浓度在山区相对较高,而在平原地区有机氯浓度相对较低,除了有机氯农药的用量和特性外,气候条件、地形地貌也同样对于有机氯农药的降解分布起到至关重要的作用。α-HCH与γ-HCH残留浓度的线性关系可以反映出γ-HCH到α-HCH的转化进程,这与浙江省该地区长期处于厌氧条件是有关系的,因为DDT的残留与o,p′-DDT/p,p′-DDT的比值存在线性关系,所以有三氯杀螨醇的输入,DDT的残留与o,p′-DDT的DEVrac(EF减去0.5的绝对值)值不存在线性关系。同分异构体的比率和对映体分数可以判断该地区的污染源是近期输入还是历史残留,在本实验中我们发现了TOC和生物有机碳的含量与HCHs和DDTs的含量存在一定的关系,同时还发现EF值和土壤的理化性质存在一定联系。HCHs在所有46个样品中的残留量变化范围是0-50.56μg/kg。除了杭州的一个样品外每个样品中的浓度值都小于50μg/kg的HCHs土壤环境质量一级标准(GB 15618-1995),DDTs在46个样品中的变化范围是3.27-529.08μg/kg,平均值为34.41μg/kg,46个样品中有2个样品(HZ10和JH 2)超过500μg/kg的DDTs土壤环境质量二级标准(GB 15618-1995),46个样品中只有3个样品检测出七氯,13个样品检测出环氧七氯(0.21-3.25μg/kg),艾氏剂和狄氏剂分别由19和18个样品中检测出来,浓度范围分别是0.13-28.61μg/kg和0.90-17.55μg/kg,硫丹的检出率偏高,达到70%,浓度变化范围是0.52-39.43μg/kg。更多还原

【Abstract】 Large quantities of organochlorine pesticides(OCPs) were historically and currently introduced into soils of Zhejiang,yet very limited information is publicly available for the present level of OCPs in the district.Past studies revealed that residues of chiral OCPs in soils were generally nonracemic.This work found the pollution level of OCPs in Zhejiang was moderate and enantiomeric fraction(EF) of chiral OCPs in nearly all samples significantly deviated from 0.5 at the present.The order of residue level and detectable ratio of OCPs is DDT＞HCH＞Endosulfans＞any one of other target OCPs,this linked with the usage and characteristics of OCPs.Residues of most of OCPs and were log-normally distributed.The spatial distribution showed that the residues in soils from mountain area were always higher than those in soils from plain in the same district.Besides usage and characteristics of OCPs,land use,climate conditions,and topography were also important factors which affect spatial distribution of OCPs.A significantly positive correlation between residues ofα-HCH andγ-HCH implied transformation fromγ-HCH toα-HCH in the region,this is consistent with the fact that soils in Zhejiang was under anaerobic conditions in most of times.Since a new input of dicolof-type DDT occurred in the region,the residues of DDT was positively and negatively correlated with the ratio of o,p’-DDT/p,p’-DDT and DEVrac of o,p’-DDT(defined as absolute value of EF subtracted from 0.5),respectively.The combination of isomeric and enantiomeric ratio is thus useful tool to identity "new" or "old" source.It is interesting to note that residues of HCH and DDT were significantly correlated with TOC and biomass of soils,respectively,and significant correlation between EF and properties of soils was also observed in this study.The two characteristics, significant correlation between residues of OCPs and TOC or biomass and derivation of all chiral OCPs from racemic,made the contamination of OCPs in Zhejiang be different that in previously studied regions, indicated the contamination is complex and should be received more concern in future.The residues of total HCHs in agriculture soils ranged from nondetectable to 50.56μg/kg.The levels of HCHs in all samples were lower than the first grade of guidelines of "Environmental Quality Standard for Soils in China(GB15618-1995)(50μg/kg),except HZ 10 Levels for DDTs in this study ranged from 3.27 to 529.08μg/kg with a geometric mean(GM) of 34.41μg/kg,Of the 46 soils analyzed in this study,two soils(HZ10 and JH 2) had levels of DDTs above 500μg/kg which is the maximum permitted concentration of DDTs in agriculture soils(the second grade of GB15618-1995,China).Residue of HEPT were above LOQ in only 3 of soils.HEPX had a higher detection ratio than HEPT and was found in 13 samples with levels ranging from 0.21 to 3.25μg/kg,aldrin and dieldrin were detected in 8 and 18 samples, respevtively,TC and CC had nearly similar detection frequence and were found in 19 and 18 of the soils analyzed with the concentration range of 0.13-28.61μg/kg and 0.90-17.55μg/kg,respectively,endosulfans had wider distribution than the other 6 OCPs in soils with a detection ratio of 70%and levels range of 0.52-39.43μg/kg.更多还原