E-mail: michael@shboqu.com   |   Expert in Water Quality Measurement and Water Treatment Project

Rapid detection method and principle of residual chlorine in water

by:BOQU     2023-03-29
Chlorine-containing preparations are the earliest and most widely used drinking water disinfectants, which are of great significance for implementing disinfection and ensuring the disinfection effect. The available chlorine in drinking water chlorine preparation is a method to characterize the oxidation ability of chlorine-containing disinfectant with chlorine gas as the standard. The higher the effective chlorine content in the disinfectant, the stronger the disinfection ability and the more thorough the killing of microorganisms. Residual chlorine refers to the residual chlorine content in water after the disinfectant has been used for a certain period of time. After the water is chlorinated and disinfected, if sufficient residual chlorine is maintained, it means that not only the disinfection effect is reliable, but also the disinfection effect is continuous. This speed test paper is a broad-spectrum chlorine detection test paper, which is used to judge whether the effective chlorine content in the disinfectant solution reaches the disinfection application value, whether the residual chlorine content in the water can ensure the disinfection effect, and whether the concentration is too high to affect the sensory properties of the water or even cause Secondary chemical pollution. Rapid detection method of residual chlorine in water Detection principle of residual chlorine in water: This rapid detection box uses the principle of visual colorimetry for semi-quantitative detection, and the medicine block on the test paper is in contact with the sample for color reaction, and the available chlorine in the sample is determined according to the color of the test paper , Residual chlorine content. Attached is the Hygienic Specifications for Catering Industry and Collective Dining Distribution Units (Wei Jianfa [2005] No. 260) Supplementary 'Bleaching Powder, Bleaching Powder Disinfectant Hygienic Quality Specifications (Trial)' document, the concentration and use of disinfectants are as follows: GB/T 5750.11-2006 stipulates that the concentration of residual chlorine in the factory water should be [0.3, 4] mg/L, the drinking water at the end of the pipe network should be ≥ 0.05 mg/L, and the swimming pool water should be in [0.2, 1.0] mg /L, and the disinfection water for soaking feet in swimming pools should be [5, 10]mg/L. Test steps of test paper for rapid detection of residual chlorine in water: 1. Determination of effective chlorine in disinfectant: remove 1ml of poison sample, add 4ml of water, shake well, immerse all test paper pieces in the sample liquid, take them out immediately, wipe off the excess liquid on the edge of the test paper, and make the test paper pieces face upward Place it, compare it with the color card in 40 seconds, and read the result. When the color of the test paper is too dark and exceeds the range of the color chart, dilute the sample and measure it. 2. Determination of residual chlorine in water: take an appropriate amount of sample in a clean and dry container, immerse the test paper piece in the sample liquid and take it out immediately, wipe off the excess liquid on the edge of the test paper , Place the test paper block facing up horizontally, compare it with the color card in 40 seconds, and read the result. Result judgment: 1. The available chlorine concentration of the diluted sample is equal to the reading value of the colorimetric card multiplied by the dilution factor, and the residual chlorine concentration in water is equal to the reading value of the colorimetric card; 2. Comparing the detected value with the above standard, the available chlorine concentration is greater than Or equal to the required value of the corresponding disinfection object is qualified, less than the required value is unqualified; drinking water conforms to the provisions of GB/T 5750.11-2006 as qualified, and does not meet the requirements as unqualified. Precautions for rapid detection of residual chlorine in water: 1. This test paper is easily affected by moisture, light and heat, and the working environment temperature is required to be 15°C ~ 35°C, and the relative humidity is ≤75%. 2. Do not touch the reaction area of ​​the test paper with your hands, and do not take out the desiccant. The taken out test paper strips should be used immediately, and each test paper can only be used once. 3. This test paper is not suitable for the detection of available chlorine of chlorine dioxide. Storage conditions and expiry date of rapid detection of residual chlorine in water: the test paper should be stored in a dry environment at room temperature and away from light, and should not be placed in the refrigerator. Valid for 12 months. List of standard equipment for the determination of residual chlorine in water: instruction manual, test paper, desiccant, certificate of conformity, sample tube, straw.
Custom message
Chat Online 编辑模式下无法使用
Leave Your Message inputting...