Study Of Sensor Technology Based On Rapid Analysis Of Carbon Dioxide In The Seawater

With the development of human society,industrialization,a lot of fossil fuel is used as energy material.The burning of fossil fuels not only pollute the environment but also produce a large amount of carbon dioxide,which makes the carbon dioxide in the atmosphere increases year by year.Because of increased carbon dioxide in the atmosphere,in the process of seawater dissolved carbon dioxide increase,leading to ocean acidification,lowered the water p H value,promote substances such as calcium carbonate solubility in the water,coral and shellfish biological damage to Marine fisheries,threatening the human needs,increasing the quantity and quality of the seafood.Carbon dioxide carbonate in the global system plays an important role in biological chemical and physical cycle,achieve rapid carbon in seawater on the spot measurement for global carbon change,Marine fishery production is of great significance.There are many methods for determination carbon dioxide in seawater.However,most of them applied to the laboratory detection,and less of them can be directly used to detect seawater in situ.Their principles of determination are the separation of CO2 gas,and then to test the isolate carbon dioxide.This dissertation establishes the chemical analysis method that used all-solid-state carbonate ion selective electrode to directly and quickly measurement in situ carbon dioxide.The way breakthrough the limitations of the traditional need for water sample pretreatment.It almost not be affected by the outside world and determination process.The preparation of the good selective all-solid-state carbonate ion-selective electrode to anion of components in the seawater.The electrode was optimized test conditions.Then gradually explored the electrode for the determination of the best conditions in the seawater.It built seawater carbon dioxide in-site rapid detection system based on the all-solid-state carbonate ion-selective electrode.The main conclusion through above the research,including the following two aspects of content:First,It established of a solid-state carbonate ion selective electrode determination of seawater method of carbon dioxide.Traditional detection methods need to seawater pretreatment extract inorganic carbonate in the seawater,or directly detect carbon dioxide gas in the separation of the water of the sea.The establishment of this method saves the steps of sample pretreatment,making the measurement process simple,quickly and easily to operate,realizing automatic measurement.Characteristics of this method is the use of seawater of carbonate balance to calculate the value of the carbon dioxide which result more accurate.Through the study on the properties of carbonate ion selective electrode.The detection limit of carbonate ion-selective electrode is 7 x 10-6 mol · L^-1,the response slope is 29.6 m V · decade – 1 at blank background.One of the biggest of electrode in seawater interference anion is chloride ion,the selectivity coefficient of Cl-is 5.7.The carbonate ion-selective electrode selectivity over SO₄^2-?Br^-?NO₃^-?NO₂^-?SCN^-?ClO₄^- respectively is-6.29?-5.58?-4.23?-4.33?-3.75?-2.83.The detection limit of the work curve of artificial sea water for 7 x 10-6 mol · L^-1,the response slope is-24 m V · decade^-1,under the background of the sea.The carbonate ion-selective electrode of Nernst linear response range is 10-3^-10-4.5 mol · L^-1.The study shows that the developed carbonate electrodes have good performance,fully applying the determination of seawater.Second,it built the scene of the seawater carbonate carbon dioxide rapid detection sensor system based on all-solid-state ion-selective electrode.The system divided three major functional parts: floe system,detection pool,detection system.The flow system is responsible for the introduction of water into the pool and discharge detection.Detecting pool's main function is to provide the system in space,and place the sensor part of the detection system,protecting the sensor at the same time from seawater corrosion,and prevent the biofouling on the sensor.Detection system is the core of the instrument,contains two subsystems,sensor system,control/data processing system,the two subsystem is a data acquisition function,one is the processing functions.