Seawater total organic carbon automatic on-line monitoring instrument

Abstract

The invention relates to a seawater total organic carbon (TOC) automatic on-line monitoring instrument which comprises an inorganic carbon removing unit, a sample introduction unit, an oxidation unit,a cooling unit, a gas-liquid separating unit and a carbon dioxide detecting unit; wherein the inorganic carbon of the sample to be detected is blown and removed by the inorganic carbon removing unit;then the sample to be detected is sent into a pipeline through a six-way valve, mixed with potassium persulfate sodium borate, heated in an ultraviolet device and has catalytic reaction under the ultraviolet irradiation; the organic carbon in the sample is oxidized into inorganic carbonate which is then mixed with hydrochloric acid to be transformed into carbonic acid; and after gas-liquid separation, carbon dioxide gas can be formed and finally enters into a non-dispersive infrared analyzer to be detected. The instrument can be simultaneously used for measuring the inorganic carbon and the organic carbon in the water sample, so that the TOC in the seawater can be rapidly and automatically measured in an on-line way.

Description

technical field [0001] The invention relates to a marine monitoring instrument, in particular to an automatic on-line monitoring instrument for total organic carbon in seawater. Background technique [0002] Total organic carbon (abbreviated as TOC) is a comprehensive index that characterizes the total amount of organic matter in water, and it represents the sum of organic matter in water. TOC can not only reflect the degree of pollution of water body by organic substances, but also can reflect the situation of life activities in water body as a biogenic element. Moreover, TOC plays an important role in the study of the global cycle of carbon. At present, TOC measurement has been widely used in rivers, lakes and ocean monitoring, and has gradually become a routine parameter for water quality monitoring. [0003] The determination of TOC in water usually consists of three steps: (1) sample pretreatment, including sampling, filtration, acidification, and removal of inorganic ...

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Problems solved by technology

This method completely oxidizes organic matter, but the disadvantage is that too many consumables are needed for the determination of seawater, and the price is relatively expensive.

[0008] At present, there are instruments made of these principles on the market, but the main problems are as follows: (1) Domestic instruments have low precision and high detection limits, and can only be used for the determination of high-concentration TOC in freshwater systems such as industrial sewage, and cannot meet the requirements of high-concentration TOC in seawater systems. Analysis of low-concentration TOC; (2) Imported instruments are expensive, and oxidation tubes in key parts need to be replaced frequently, which not only causes high measurement costs and is not suitable for my country's national conditions, but also increases the difficulty of instrument maintenance and affects the continuity of data; (3) At present, none of the commercially available instruments can realize the automatic online monitoring of TOC, especially the on-board real-time measurement cannot be realized, and it cannot meet the comprehensive and three-dimensional monitoring needs of marine surveys

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