Study On Electrochemical Detection Technology Of Phenolic Contamination In Oilfield Wastewater

Organic pollutants in oilfield wastewater of phenolic containing highly toxic that is greatly harmful to animals and plants and environmental.Therefore Real-time detection and control of phenol are very important.Comparing with standard 4-amino antipyrine,electrochemical analysis method has the advantages of simple operation,high sensitivity and real-time advantages.The application of this method for the detection of phenol has important scientific significance and application prospect.This paper adopts polymer,multi-carbon nanotubes or gold nanoparticles modified electrode surface for the preparation of the working electrode.The application of three electrode system was investigated by cyclic voltammetry in phenolic modified electrode electrochemical behavior,electrochemical properties of electrochemical impedance spectroscopy characterization of modified electrode,differential pulse voltammetric detection standard curve and the determination limit.This thesis is summarized as follows:(1)A carbon paste electrode is modified by polying zinc,which is used to detect phenol.In the scan rate of 100 mV/s?phosphate buffer solutions of pH 7.0,linear calibration graphs were obtained in the range of 21?mol/L~292?mol/L?357?mol/L~922?mol/L,with a detection of limit of 9×10-6mol/L.(2)A carbon paste electrode(CPE)modified by poly-sulfosaliculic acid and multi-walled carbon nanotubes composite(poly-SA/MWCNT)has been constructed and used as electrochemical sensor for determination of catechol.Under optimized conditions,the catechol of limit and linear range is 0.16 ?mol/L,3 ?mol/ L~240 ?mol/ L.(3)The gold nanoparticle is successfully deposited on the surface of the carbon paste electrode by electrodeposition.And the poly-sulfosaliculic acid?multi-carbon nanotubes modified electrode are used to detect the o-nitrophenol and phenol.The experimental results show that the o-nitrophenol and phenol of peak potential(0.932 v,0.679v)and the peak potential difference of 0.3V can distinguished.Under optimized conditions,the o-nitrophenol of limit and linear range is 0.03?mol/L,2?mol/L~214?mol/ L.