A detection method of phosphorus in water based on permutation entropy

Abstract

The invention provides a method for detecting phosphorus in water based on permutation entropy, comprising the following steps: step 1: taking a water body sample to directly prepare a potassium dihydrogen phosphate solution with a concentration of 1-5mg / L; step 2: measuring by ultraviolet spectrum Its absorbance; step 3: record the absorbance corresponding to its different concentrations; step 4: process the data obtained in step 3 through the permutation entropy algorithm, and use the matlab calculation method to continuously test the value of permutation entropy. Best is based on finding the best embedding dimension and delay time. The invention does not need to add any chemical reagents to reduce secondary pollution; the detection operation is simplified and automated, and it is easy to realize in-situ measurement; the measurement range is expanded, and the accuracy is basically consistent with the phosphorus molybdenum blue method; The impact of related impurities on the water sample and amplify the small changes in the signal are more suitable for detecting low-concentration solutions.

Description

technical field [0001] The invention relates to a method for detecting phosphorus in water, in particular to a method for detecting phosphorus in water based on permutation entropy. Background technique [0002] To detect the total phosphorus content in the existing water quality, the commonly used spectrophotometric method is mainly the phosphomolybdenum blue method, which is a conventional chemical laboratory analysis method. The principle of the phosphomolybdenum blue method is that orthophosphoric acid first reacts with molybdate to form pale yellow phosphomolybdenum heteropolyacid, and then use a reducing agent to reduce the yellow phosphomolybdenum heteropolyacid to phosphomolybdenum blue complex under certain conditions. The reaction formula is as follows: [0003] PO43-+12MoO42-+24H+=PO43-·12MoO3+12H2O [0004] P(Mo3O10)43-+H++ reducing agent→(MoO2·4MoO3)2·H3PO4+MoO2+H2 [0005] The determination method of total phosphorus is to use ammonium molybdate, antimony po...

AI Technical Summary

Problems solved by technology

[0011] The purpose of the present invention is to solve the existing methods for detecting total phosphorus content in water quality, which need to add a variety of chemical reagents, the detection operation is complicated, the measurement range is small, and the relevant impurities have a great influence on the water sample. Compared with the phosphorous molybdenum blue spectrophotometric method, the entropy detection method of phosphorus in water has the advantage of not needing to add any chemical reagents and reducing secondary pollution; the detection operation is simple and automatic, and it is easy to realize in-situ measurement; the phosphorous molybdenum blue detection method The linear relationship between the absorbance and the concentration is 0-0.6mg / L, and the detection method based on the permutation entropy algorithm can obtain the change of different concentrations through the change of the entropy value, which expands the measurement range, and the accuracy is basically consistent with the phosphomolybdenum blue method ; Permutation entropy algorithm reduces the impact of related impurities on water samples in spectral detection, and amplifies small changes in signals, and is more suitable for detecting low-concentration solutions

Images