Study On The Digestion And Detection Of Heavy Metal Complexes In Water

Along with China's rapid economic development and people living standard rise environmental ecological problems are also increasingly prominent in our country,the water environment of rivers,lakes and oceans is polluted by different degrees,and the heavy metal pollution is characterized by its biological accumulation and latent capacity,and the regulation and prevention and control are extremely urgent.It is of great significance to accurately detecting and detecting pollution before pollution occurs and to buy time for pollution and treatment.Because of the complexity of the water environment,existing speciating of heavy metals in water is diversiform,usually including the suspended state,such as free ion state,complexing state,so the sample digestion pretreatment is needed to obtain accurate results,this thesis chose the PbO₂/Ti material based on the advanced oxidation technologies as the digestion electrodes in electrochemical analysis,which is second only to oxygen evolution potential of fluorine,to various forms of heavy metals in water degradation can be chemical method to detect ion state electricity.We chose electrochemical anodic differential pulse stripping voltammetry to detect heavy metals,this method can detect a variety of heavy metal ions at the same time,the operation is simple,the water samples from the testing standard and the actual water samples,the result repeatability,ion interference test and verify the reliability of the method established a new method for digestion and detection together.In addition,the design and preparation of microelectrode chips were studied and the experimental results were obtained by considering the requirements of portable and miniaturized heavy metal detection in recent years.The main work of this paper is as follows:1.Based on the principle of the advanced oxidation technologies,Ti/PbO₂ electrode is chosen as the digestion of organic metal electrode materials,optimize the preparation process of the solution concentration,reaction temperature,the working potential applying parameters,such as time,size and analyses of electrode materials by the morphology and elemental composition,and the determination of the electrode of digestion efficiency,EDTA-Cu digestion efficiency above 85%in 10 minutes.2.Based on electrochemical anodic differential pulse stripping voltammetry,using homemade metal detector,using glassy carbon electrode and electrode working system,optimized the enrichment of potential?1v?and time?180 s?,set up three kinds of copper,lead,cadmium ion detection method at the same time,the method to eliminate the interference between copper,lead and cadmium ions,also eliminates the Ni²⁺and Mn²⁺ions,repetitive error can be controlled within±9%.3.Based on MEMS technology,design a new resolution and detection of micro electrode chip,selects the Megnetron Sputtering technology and Photolithographic technology for micro electrode graphical,Ti/PbO₂ as working electrode,bismuth film microelectrode modified Pt electrode for detection,Ag/AgCl reference electrode for detection,Pt as counter electrode,using microelectrode was prepared by the lead ions concentration experiments,chose 50 ppb,80 ppb,100 ppb,150 ppb and 200 ppb,show a good linear relationship.