Method and device for removing high chloride ions in wastewater COD on-line detection

Abstract

The invention discloses a method and a device for removing high chloride ions in wastewater COD on-line detection. The method adopts a filter, a conductivity meter, a membrane processor and a control system thereof which are connected by pipes in turn, and comprises the following steps: firstly, filtering the wastewater to remove most of suspended solid containing organic pellicles in the filtered wastewater; and then, detecting the conductivity of the wastewater, and inputting detection signals to the control system of the membrane processor. If the conductivity is more than 3,500us / cm, the control system of the membrane processor starts the membrane processor to work, the high chloride ions in the water sample are selectively removed, and organic substances cannot penetrate the membrane; and if the conductivity is less than 3,500us / cm, the membrane processor is only used as a passage for subsequent COD detection. The chloride ions in the treated water sample are less than 1,000 mg / L, so the influence of the high chloride ions in the wastewater on a measuring value of an on-line COD measuring instrument can be effectively eliminated. Moreover, the organic pellicles in the water sample are also removed, so the interference and the damage to electrodes caused by the organic pellicles are avoided.

Description

technical field [0001] The invention relates to waste water detection technology, in particular to a method and device for waste water on-line COD detection and removal of high chloride ions. Background technique [0002] The main interference factor in the process of wastewater COD detection is the interference caused by high chloride ions in wastewater. The high chloride ions in water samples are easily oxidized by oxidants, and the consumption of oxidants leads to high measurement results. Especially for wastewater with high chlorine and low COD, the data measured by the national standard method has almost no reference value. For a long time, the majority of environmental protection workers have made unremitting efforts on how to eliminate the interference of high chloride ions, and successively proposed mercury salt method, standard curve correction method, silver ion precipitation method, low concentration oxidant method, sealed digestion method and chlorine gas absorpt...

AI Technical Summary

Problems solved by technology

[0002] The main interference factor in the process of wastewater COD detection is the interference caused by high chloride ions in wastewater. High chloride ions in water samples are easily oxidized by oxidants, and the consumption of oxidants leads to high measurement results.

Especially for wastewater with high chlorine and low COD, the data measured by the national standard method has almost no reference value

For a long time, the majority of environmental protection workers have made unremitting efforts on how to eliminate the interference of high chloride ions, and successively proposed mercury salt method, standard curve correction method, silver ion precipitation method, low concentration oxidant method, sealed digestion method and chlorine gas absorption correction method, etc. method, the above method is only suitable for offline COD analysis, not for online COD analysis

[0003] At present, there are few studies on how to eliminate the high chloride ion interference of the measured value of the electrolytic online COD measuring instrument, and there is no method and equipment to effectively eliminate the high chloride ion interference of the measured value of this type of COD measuring instrument at home and abroad.

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