| With the rapid increase of human economic activity and the prosperity of modern manufacturing industry,various heavy metals are widely used.A large number of heavy metal elements are discharged into the sea through municipal drainage,river into the sea,land non-point source collection and other ways,and finally enter the human body through bioaccumulation and food chain,causing serious harm to human body and difficult to cure.The premise of prevention and control of heavy metal pollution in marine ecological environment is heavy metal detection.Most of the existing detection technologies are expensive and difficult to operate,so it is difficult to be widely used,a kind of seawater heavy metal detection instrument with convenient detection,high efficiency and low relative cost is urgently needed.This paper takes this as the research goal,the project team independently developed independently developed the electrothermal evaporation dielectric barrier discharge plasma atomic emission spectrometry detection system(ETV-DBD-AES),and the ETV-DBD-AES method for heavy metal detection in seawater was established and validated,it was applied to the marine environmental monitoring in the southern Wendeng sea area of Weihai City,and achieved good results.Taking lead and cadmium in water as the detection objects,the instrument parameters of ETV-DBD-AES were determined.On this basis,the detection conditions of seawater extraction and concentration of organic samples were optimized,the curve equation of cadmium was confirmed as y=85.561x-151.85,R~2=0.9959,and the curve equation of lead was confirmed as y=12.512x-30.762,R~2=0.9937;The seawater sample can be directly detected by concentration of50 times,3-5 u L of sample is consumed at one time;The detection limits of lead and cadmium are 2.48μg/L and 0.05μg/L respectively,and the limits of quantification are 8.28μg/L and 0.18μg/L,respectively.In addition,this method is used to detect the"trace elements in seawater"solution of the national standard material of the second Institute of Oceanography of the Ministry of natural resources,the results show that it is qualified.The established ETV-DBD-AES method was compared with the traditional atomic absorption spectrometry(AAS)for the determination of lead and cadmium in large quantities of seawater sampless,the results of ETV-DBD-AES and AAS were basically the same,the difference of cadmium concentration ranges from 0.4%to 11.2%,and that of lead is from 0.5%to 13.2%.ETV-DBD-AES technology can be applied to the detection of actual seawater samples.The ETV-DBD-AES detection method was established to monitor the heavy metal lead and cadmium in the South Wendeng sea area of Weihai City,the status of heavy metal pollution in the sea area was mastered,and the pollution sources were analyzed.A total of 18 monitoring stations were set up in the study,and the lead and cadmium content data of the sea area in 2018and 2019 were obtained.The results show that the pollution degree of the sea area belongs to the"light pollution"level,and the water quality status is"general";the potential ecological harm of cadmium is greater than that of lead,and the comprehensive potential ecological harm index belongs to the"slight ecological harm"level.Jinghai Bay is the most serious area of heavy metal pollution in the south of Wendeng;According to the analysis,land source and river into the sea are the main sources of pollution.The pollution of lead and cadmium in the estuary of Qinglong river is deteriorating.The pollution of lead in the estuary of sow River and Changyang river is obviously improved,but the pollution of cadmium is not obviously improved. |
