Study On The Detection Method Of Naphthenic Acid In Oilfield

Naphthenic acid is an organic pollutant in the water from the oil field.It has great ecotoxicity and serious harm to aquatic organisms,and it will cause serious ecological pollution with the discharge of the effluent from the oil field.Therefore,it is necessary to detect the naphthenic acid in the extracted water from the oil field.At present,the methods for detecting naphthenic acid are generally analyzed and tested on the basis of crude oil.However,for the detection of naphthenic acid in the extracted water,these methods are not applicable,complex operation and strong professionalism.Through the study of the characteristics and detection methods of the organic pollutants in the water from the oil field,the electrochemical method and spectrophotometric method are proposed for the detection of naphthenic acid in the extracted water from the oil field.These two methods have the advantages of simple operation,high flexibility,strong anti-interference ability and strong stability.In the electrochemical method,the electrode was prepared by hydrothermal synthesis method.The electrochemical behavior of the naphthenic acid on the modified electrode was studied by cyclic voltammetry,the electrochemical impedance method was used to characterize the electrochemical performance of the modified electrode by the cyclic voltammetry.The standard curve and detection limit were measured by the differential pulse voltammetry,and the spectrophotometric method was used to determine the standard curve and detection limit.The spectrophotometric method was used to determine the standard curve and detection limit.The three electrode system was used to determine the standard curve and detection limit.In this method,the maxim?m absorption peak of Cu²⁺,naphthenic acid and pyridine was mixed with three elements,and the content of naphthenic acid was calculated by the determination of naphthenic acid absorbency.It is proved by the experiment that the electrochemical method and spectrophotometric method can successfully detect the content of naphthenic acid in the water extracted from the oil field,which is of great practical significance to the treatment of naphthenic pollutants in the water from the oil field.The work of this paper is s?mmarized as follows:?1?Study on the characteristics and hazards of oilfield produced water;?2?The related data were reviewed and the structural characteristics of naphthenic acids were studied by mass spectrometry.The concentration of naphthenic acid was detected by FT-IR,biological method,photolysis method and ozone method.?3?The lanthanum doped zinc tungstate?La-doped ZnWO₄?modified electrode was prepared by electrochemical method.When the scanning speed was 100mV/s and pH was 7,the detection limit of naphthenic acid was 2.4×10^-6mol/L,and the linear range was31?mol/L²97?mol/L?367?mol/L⁹55?mol/L.Compare and analyze the experimental data with other methods.?4?The maximum absorption peak of Cu²⁺,naphthenic acid and pyridine was mixed at705nm by spectrophotometry.The absorbance of naphthenic acid was determined and the content of naphthenic acid was calculated.The linear range of the method is 0.21 mol/L⁹9.53mol/L and the detection limit is 1.34×10^-5mol/L,and the relative error is less than 5%.Compare and analyze the experimental data with other methods.