钦州湾入海口邻苯二甲酸酯分布特征及生态风险评价

为了解钦州湾入海口邻苯二甲酸酯(PAEs)污染情况,以钦州湾入海口沉积物为研究对象,对其中5种PAEs进行浓度及分布特征研究,并探讨PAEs与总有机碳(TOC)相关性,进行了PAEs生态风险评价。结果表明,钦州湾入海口沉积物中邻苯二甲酸二甲酯(DMP)、邻苯二甲酸二乙酯(DEP)、邻苯二甲酸二丁酯(DBP)、邻苯二甲酸丁苄脂(BBP)和邻苯二甲酸二(2-乙基)己脂(DEHP)均有检出,检出率为100%,PAEs总质量浓度(以干质量计)为4.158～8.455mg/kg,平均值为7.011mg/kg。钦州湾入海口沉积物中PAEs以DEHP与DEP为主,PAEs浓度表现为DEHP>DEP>DBP>BBP>DMP,平均值分别为3.932、2.212、0.580、0.241、0.047mg/kg。钦州湾入海口沉积物中PAEs主要分布在钦江、金鼓江和龙门港。钦州湾入海口沉积物中TOC质量浓度为0.912～19.305mg/g,平均值为7.162mg/g,TOC与PAEs总浓度的相关系数为0.609,无显著相关性(p>0.05)。与国内外其他区域沉积物中PAEs浓度相比,钦州湾入海口沉积物中PAEs总浓度低于国内外大部分流域,但DBP、DEP和DMP浓度超过美国土壤PAEs控制限值,存在着一定的生态风险。

Distribution characteristics and ecological risk evaluation of phthalic acid esters in sediments of Qinzhou Bay estuary

To understand the pollution of phthalic acid esters(PAEs)in the estuary of Qinzhou Bay in Guangxi,the content and distribution characteristics of five kinds of PAEs were studied.The relationship between PAEs and total organic carbon(TOC),and ecological risk assessment were also studied.The results showed that di-(2-ethylhexyl)phthalate(DEHP),dibutyl phthalate(DBP),diethyl phthalate(DEP),butyl benzyl phthalate(BBP)and dimethyl phthalate(DMP)were detected in the sediments,the detection rate was 100%,and the total concentration of PAEs was 4.158-8.455 mg/kg,and the average value was 7.011 mg/kg.The main PAEs in the sediment of Qinzhou Bay estuary were DEHP and DEP,and the average values ranked DEHP,DEP,DBP,BBP and DMP,with 3.932,2.212,0.580,0.241,0.047 mg/kg,respectively.The PAEs in the estuary of Qinzhou Bay was mainly distributed in Qinjiang river,Longmen port and Jingu river.The concentration of TOC in the sediment of Qinzhou Bay estuary was 0.912-19.305 mg/g,and the average value was 7.162 mg/g.The correlation coefficient between TOC and PAEs was 0.609,and there was no significant correlation between TOC and PAEs(p>0.05).The concentration of PAEs in the estuary sediment of Qinzhou Bay was lower than most watersheds at home or abroad.The concentration of DBP,DEP and DMP was higher than American soil PAEs control limits and there would be a certain ecological risk.