洞庭湖水和沉积物中有机磷酸酯的分布特征及风险评估

Distribution Characteristics and Risk Assessment of Organophosphates in Water and Sediment in Dongting Lake

有机磷酸酯(OPEs)作为阻燃剂和添加剂,广泛应用于生产生活,在环境中普遍检出.为探究其环境行为,采用超高效液相色谱-串联质谱联用仪(UPLC-MS/MS)测定洞庭湖的表层水和沉积物样品中13种OPEs,共检出11种,检出率分别为5.26%~100%和58.3%~100%,∑OPEs含量范围分别为2.06~2 028 ng·L^(-1)和19.6~2 232 ng·g^(-1).从整体上看,表层水中∑OPEs浓度呈现入湖河流>湖区>出口的趋势,而沉积物中浓度的空间分布与水动力呈相反趋势.和国内外湖泊相比,洞庭湖OPEs污染浓度处于较高水平.在检出的11种OPEs中,磷酸三正丁酯(Tn BP)和磷酸三异丁酯(Ti BP)是水中主要的污染物,占∑OPEs的52.3%和22.4%;沉积物中主要为磷酸三苯酯(TPh P),占总量的31.2%.相关性和主成分分析结果表明,洞庭湖OPEs污染主要受工业生产排放、渔业养殖业和大气沉降的影响.风险熵评估结果显示,水体中检出的多数OPEs的生态风险相对较低,但在部分采样点由2-乙基己基二苯基磷酸酯(EHDPP)引起的生态风险需引起关注.

Organophosphates(OPEs)are widely used as flame retardants and additives and thus are commonly detected in the environment.In order to explore their environmental behavior,the concentrations of 13 OPEs in the surface water and sediment of Dongting Lake were analyzed using UPLC-MS/MS.The results showed that 11 OPEs were detected,with detection frequencies of 5.26%-100%and 58.3%-100%,and the concentrations of OPEs were 2.06-2028 ng·L^(−1) and 19.6-2232 ng·g^(−1) in water and sediment,respectively.Overall,contamination concentrations were ranked in descending order as follows:inflowing rivers,lake area,and outlet,whereas the spatial distribution of concentrations in sediment was inversely proportional to hydrodynamics.The concentration of OPEs in Dongting Lake was at a high level compared with that of domestic and foreign lakes.Among the detected 11 OPEs,tri-iso-butyl phosphate(TnBP)and(TiBP)were dominant in water,accounting for 52.3%and 22.4%ofΣOPEs,respectively.TPhP was the dominant OPEs in sediment,accounting for 31.2%ofΣOPEs.The correlation and principal component analysis indicated that OPEs pollution in Dongting Lake was mainly affected by industrial production emissions,fishery aquaculture,and atmospheric deposition.The assessment results of the risk entropy showed that most of the detected OPEs in water had relatively low ecological risks,whereas the ecological risk of 2-ethylhexyl diphenyl phosphate(EHDPP)at some sampling points requires further attention.