Can the total phosphorus water quality monitor be used for sewage detection (the principle of total phosphorus water quality monitor)

Can the total phosphorus water quality monitor be used for sewage detection? The total phosphorus water quality monitor is a self-developed product, designed and manufactured in accordance with the new national regulations 'Rapid Digestion Spectrophotometry (HJ/T399-2007)', and is suitable for many testing standards at home and abroad. The total phosphorus water quality monitor can be widely used in the detection of industrial wastewater, urban sewage, domestic sewage and surface water in rivers and lakes.

The main sources of total phosphorus in water bodies are domestic wastewater, industrial wastewater and fertilizer farmland water. Phosphorus is one of the important nutrients for plant growth. If the phosphorus in the water body exceeds the standard, algae and other plankton will multiply rapidly, the dissolved oxygen content in the water will drop sharply, and the water quality will continue to deteriorate and lead to the death of the organisms in the water. Total phosphorus is a very important item in water quality testing. What is the principle of the commonly used total phosphorus water quality monitor?

The total phosphorus water quality monitor generally adopts ammonium molybdate spectrophotometry. Let's take a look at the principle, steps and precautions of total phosphorus detection.

1. Detection principle of total phosphorus water quality monitor: Digest the sample with potassium persulfate (or nitric acid-perchloric acid), and oxidize all the phosphorus contained in it to orthophosphate. In an acidic medium, orthophosphate reacts with ammonium molybdate to form phosphomolybdic heteropolyacid in the presence of antimony salt, which is immediately reduced by ascorbic acid to form a blue complex. Determine the content of total phosphorus by detecting the absorbance of the sample.

2. Detection steps of total phosphorus water quality monitor

(1) Standard curve drawing

Digestion: According to the relevant requirements, prepare standard solutions of phosphate with different concentrations, add the corresponding digestion solution, and complete the digestion under the specified digestion conditions.

Color development: add the corresponding reagents for reaction color development.

Curve drawing: measure the absorbance of each standard solution and draw a standard curve of total phosphorus. The special total phosphorus detection equipment has a built-in standard curve when it leaves the factory, so there is no need to make it by yourself.

(2) Sample detection

Digestion: Take a certain amount of water sample as required, add the corresponding digestion solution, and complete the digestion under the specified digestion conditions.

Color development: add the corresponding reagents for reaction color development.

Detection: Using pure water as a reference, measure the absorbance of the sample, and find out the content of total phosphorus on the standard curve of total phosphorus. After pressing the 'Detect' button on the dedicated total phosphorus testing equipment, the total phosphorus testing results will be displayed directly without conversion.