采用5点法对珠江广州河段白鹅潭水域进行垂线采样,并采取表层沉积物的界面水。水样采用GF/F玻璃滤膜过滤分离出颗粒相和溶解相,据美国EPA标准对有机氯农药进行定量分析,结果显示有机氯农药浓度范围是23.89~61.69ng/L;据有机氯农药浓度的垂向分布特征、颗粒相为主要输运方式的DDTs的中下层高浓度跃层的形成、以及有机氯农药在颗粒相和溶解相浓度分布和分配系数表明,水柱上层和下层水体的有机氯农药的输入方式有较大的差异,结合主成分分析结果,在流速增加的动力条件下,表层沉积物存在二次污染的风险。
Six water samples in different depths in water column from Guangzhou channel of Humen estuary in the Pearl(Zhujiang) River were collected, and were filtered by GF/F glass fiber filter. Organochlorine pesticides (OCPs) in particulate and dissolved phase were identified and measured based on USEPA 8000 series methods and under quality assurance and quality control (QA/QC). Concentrations of OCPs varied from 23.89 to 61.69 ng/L. The vertical distribution of OCPs, the partition coefficients (Log Kp) of OCPs between particulate and dissolved phases, and the elevated concentrations of DDTs in the deeper sampling locations in the water column indicated that the inputs of OCPs were different between the surface water and the bottom water in the water column. The inputs of OCPs in the bottom water were correlated with the changes of dynamics in the estuary, and it indicated that the resuspension of surface sediment occurred with the increasing of rapid water current in tide estuary; and the resuspension of surface sediment will induce the secondary pollution of OCPs to the aquatic environment. The results of PCA also suggested that the resuspension of surface sediment existed in a certain hydrodynamic condition at Bai'etan in Humen estuarine of the Pearl River.
[1] Iwata H, Tanabe S, Sakai N,et al. Geographical distribution of persistent organochlorines in air, water and sediments from Asia and Oceania and their implications for global redistribution from lower latitudes [J]. Environmental Pollution, 1994, 85: 15-33.
[2] Loganathan B G,Kannan K. Global organochlorine contamination trends: An overview [J]. Ambio., 1994, 23(3): 187-191.
[3] 张枝焕,王学军,陶 澍,等. 天津地区典型土壤剖面多环芳烃的垂向分布特征[J], 地理科学,2004,24(5):562~567.
[4] 麦碧娴,林 峥,张 干,等. 珠江三角洲河流和珠江口表层沉积物中有机污染物研究——多环芳烃和有机氯农药的分布及特征[J]. 环境科学学报,2000,20(2): 192~197.
[5] Mai B X, Fu J M, Zhang G,et al. Polycyclic aromatic hydrocarbons in sediments from the Pearl river and estuary, China: spatial and temporal distribution and sources[J]. Applied Geochemistry, 2001, 16: 1429-1445.
[6] Mai B X, Fu J M, Sheng G Y,et al. Chlorinated and polycyclic aromatic hydrocarbons in riverine and estuarine sediments from Pearl River Delta, China [J]. Environmental Pollution, 2002, 117(3): 457-474.
[7] 麦碧娴,王锡莉,祁士华,等. 澳门水域沉积物中难降解有机物的污染现状及来源初探.//王志石.第三届澳门环境与城市发展研讨会科学论文集.澳门:澳门大学出版社,2001:62~84.
[8] 麦碧娴,杨清书,傅家谟,等. 澳门水域水柱剖面中有机污染物初步研究.//王志石.澳门环境与城市发展科学研究.澳门:澳门大学出版社,2002:125~134.
[9] 杨清书,麦碧娴,傅家谟,等.珠江干流河口水体有机氯农药的时空分布特征[J].环境科学,2004,25(2):150~156.
[10] 杨清书,麦碧娴,傅家谟,等.珠江虎门潮汐水道难降解有机污染物入海通量研究[J].地理科学,2004,24(6):704~709.
[11] 杨清书,麦碧娴,罗孝俊,等.澳门水域水体有机氯农药的垂线分布特征[J].环境科学学报,2004,24(3):428~434.
[12] Zhou J L, Maskaoui K, Qiu Y W,et al. Polychlorinated biphenyl congeners and organochlorine insecticides in the water column and sediments of Daya Bay, China[J].. Environmental Pollution, 2001,113:373-384.
