Method for detecting phosphorus in water body based on permutation entropy

Abstract

The invention provides a method for detecting phosphorus in a water body based on permutation entropy. The method comprises the following steps that 1, a water body sample is taken to be used for directly preparing a monopotassium phosphate solution with the concentration being 1-5 mg / L; 2, an ultraviolet spectrum is used for measuring the absorbance of the solution; 3, the absorbance corresponding to different concentrations of the solution is recorded; and 4, data obtained in the step 3 are processed through the permutation entropy algorithm, a matlab calculation method is used for continuously testing the value of the permutation entropy, and the best embedded dimension and delay time are solved with the basis that an obtained effect map is best. By means of the method, no chemical reagents need to be added, and secondary pollution is reduced; the detection operation is simple and automatic, and in-situ measurement is easily achieved; the measurement range is expanded, and the precision is basically consistent with the that of the phosphomolybdenum blue method; and the permutation entropy algorithm reduces influences of related impurities in spectrum detection on the water sample, the small signal changes are amplified, and the method is 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] Existing water quality detection of total phosphorus content, the commonly used spectrophotometric method is mainly phosphomolybdenum blue method, this method is a routine chemical laboratory analysis method, the principle of phosphomolybdenum blue method is that orthophosphoric acid first reacts with molybdate to form light yellow The phosphomolybdenum heteropolyacid, and then use a reducing agent to reduce the yellow phosphomolybdenum heteropolyacid to a 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 The determination method of total phosphorus is to use ammonium molybdate, antimony potassium tartrate a...

AI Technical Summary

Problems solved by technology

[0012] 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 ; The 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

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