Pollution Characteristics And Ecological Risk Assessment Of Organophosphates In Haihe River

In order to understand the current pollution status and ecological risk level of organophosphates,this paper selected the mainstream of Haihe River as the research object.The concentration level of organophosphates in the mainstream of Haihe River was monitored,the predicted no effect concentrations of organophosphates were deduced based on assessment factor method and species sensitivity distribution method respectively,and then the risk assessment was carried out at the ecosystem level.In this paper,the liquid-liquid extraction-high performance liquid chromatography-mass spectrometry method was used to determine the concentration of organophosphates in the mainstream water and sediment of Haihe River.The results showed that the concentrations of chlorinated organophosphates in water decreased as following oder:(tris(1-chloro-2-propyl)phosphate,TCPP)>(tris(2-choroethyl)phosphate,TCEP)>(tri(dichloroisopropyl)phosphate,TDCPP).In autumn,the concentrations of TCEP and TCPP gradually increased in the upper reaches of the main stream of Haihe River,stabilized in the middle and lower reaches,and gradually decreased from the estuary to the sea.In winter,the concentration of TCPP tended to be stable in the upper reaches of the mainstream of Haihe River,increased gradually in the middle and lower reaches of Haihe River,and reached the maximum in the estuary and decreased gradually from the estuary to the sea.The concentrations of aryl organophosphates decreased as following order:(triphenyl phosphate,TPhP)>(2-Ethylhexyl diphenyl phosphate,EHDPP)>(tricresyl phosphate,TCrP).TCrP and TPhP were not detected in the middle and upper reaches of the main stream of Haihe River,and there was no obvious spatial variation characteristics in the lower reaches of the mainstream of Haihe River.The concentrations of alkyl organophosphates decreased as following order:(Tributoxyethyl phosphate,TBEP)>(triethyl phosphate,TEP)>(tri-n-propyl phosphate,TPrP)>(tri-n-butyl phosphate,TnBP)>(tris(2-ethylhexyl)phosphate,TEHP).The concentrations of these compounds in Haihe River were generally low and no obvious spatial variation characteristics occurred.TCEP and TCPP were the domintant chlorinated organophosphates in sediment,however,TDCPP was not detected in any samples.The concentration of TCEPincreased gradually in the upper reaches of the mainstream of Haihe River,and the concentration in the middle and lower reaches of Haihe River was higher than that in the upper reaches of Haihe River.For TCPP,the concentration in the middle and lower reaches of Haihe River was higher than that in the upper reaches,and the concentration in the estuary was the highest.The concentrations of aryl organophosphates in sediment decreased as following order: TPhP > EHDPP > TCrP.This type of organophosphates had no obvious spatial variation characteristics.Besides,the concentrations of alkyl organophosphates in sediment decreased as following order: TBEP > TnBP > TEP > TEHP,however,TPrP was not detected in any samples.For TBEP,the concentration gradually increased along the river and reached the maximum at the estuary,but other organophosphates had no obvious spatial variation characteristics.Because of the lack of toxicity data of OPEs,this study just selected TCEP,TCPP,TDCPP,TPhP,TCrP,TEP and TBEP to conduct the ecological risk assessment.The ecological risk and joint ecological risk of these seven substances were evaluated by means of assessment factor method and species sensitivity distribution method.The results showed that the ecological risk level of these seven substances in the mainstream of Haihe River was very low.This study supplemented the pollution data of organophosphates in the mainstream of Haihe River.In addition,the ecological risk assessment of organophosphates was carried out at a ecosystem level,which can used to control the pollution of organophosphates in the mainstream of Haihe River.