Preparation and using method of water quality chemical oxygen demand (COD) detection agent

Abstract

The invention relates to preparation of a water quality chemical oxygen demand (COD) detection agent, and a method for applying the water quality COD detection agent to environmental water body COD rapid detection. The COD detection agent is prepared to form two types of liquid through mixing and dissolving of permanganate, sulfuric acid, silver sulfate, potassium dichromate, potassium persulfateand mercury sulfate, the two types of liquid are sequentially added into a to-be-detected water sample to react for 5-10 min, and then measuring is conducted through a spectrophotometer or a water quality detector. According to the COD detection agent, atomic oxygen is generated through a composite oxidant in the presence of metal ions to quickly decompose organic matter and oxidation-reduction substances in water. The detection agent does not need to be heated and then dispelled, operation is easy, sensitivity is high, multiple properties are significantly superior to those of other current market commonly-adopted COD detection agents, the detection method is significantly superior to a COD national standard monitoring method GB 11914-89, and the COD detection agent is suitable for detection of various water qualities such as ground water, groundwater, tap water, domestic sewage and industrial wastewater with the COD being larger than 1 mg / L.

Description

technical field [0001] The invention relates to the preparation of a water quality chemical oxygen demand (COD) detection agent and a method for using it for rapid detection of environmental water COD, belonging to the technical field of environmental monitoring. Background technique [0002] Chemical Oxygen Demand (COD) is an important index to evaluate the degree of water body pollution by organic matter, an important parameter to identify the treatment effect of domestic sewage and industrial wastewater, and also a core indicator for the country's responsibility system for regional water environment targets and the assessment of corporate wastewater discharge standards . COD determination is a routine work in water pollution analysis. For a long time, the national standard monitoring method (GB 119142-89) is usually used, but this method has many analytical reagents, long cycle, high energy consumption, use of highly toxic mercury salts, and complicated operation. and ot...

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Problems solved by technology

However, the above-mentioned methods all require heating and digestion, consume a large amount of energy, and must be operated indoors by professional technicians, and are not suitable for field use

[0004] The COD on-line monitor produced by German STIP company uses electrolysis to generate hydroxyl radicals with strong oxidizing ability, which can quickly oxidize organic matter in water, and has the characteristics of no need to digest water samples, short time, and easy operation (He Jianhui, Li Liangwan , Wang Bo, Research Progress in COD Determination Methods, Journal of Xihua University—Natural Science Edition, 2006, 3:51), but the equipment is expensive and requires professional and technical personnel to operate

Based on TiO 2 The photocatalytic method of nanotube arrays is based on the reaction of hydroxyl radicals as the main oxidant and organic matter, and is developing in the direction of fast, accurate, low consumption, no secondary pollution, and on-line monitoring (Zheng Qing, Han Haibo, Zhou Baoxue, etc., Chem. Research progress on new methods for rapid determination of oxygen demand (COD), Science Bulletin, 2009, 54(21): 3241-3250), but it is still in the experiment, the method is not yet mature, and has not been used in actual water quality analysis

[0005] Zhang Zheng carried out UV-VIS spectroscopy to study the new technology of COD detection (Zhang Zheng, Ultraviolet-visible spectrum water quality COD detection principle, instrument and method technology research, master's degree thesis of Chongqing University, 2017), using extreme learning machine to analyze water quality Perform principal component analysis on spectral data to extract effective spectral feature information, and then model water quality COD. The method is complicated to operate. Compared with standard monitoring methods, the accuracy of the results is not high

[0006] In summary, up to now, no simple, rapid, sensitive, accurate, and cheap COD detection reagents and detection methods have been reported.