How to remove water quality COD exceeding the standard (what are the water quality COD detection methods)

How to remove COD in water is a common indicator problem in industrial sewage and municipal sewage treatment. COD in water is often used as an indicator to measure the content of organic matter in water. The larger the COD, the more serious the pollution of the water body by organic matter. How to remove COD in water? We divide it into three points to solve.

Quick removal - chemical method:

This method is widely used in how to remove cod from water.

1. Principle: Add a cod degrading agent to the sewage to quickly decompose the COD in the water through the effect of strong oxidation.

2. Features:

5 minutes to quickly remove COD from water;

No need to change or increase equipment and processes;

Low dosage and low cost;

The removal rate is more than 96%, so that the sewage can be stably reduced to below the qualified standard;

No sediment, no secondary pollution.

Refractory COD - Microbial Method:

The microbial method is mainly divided into two stages: anaerobic and itchy.

1. Anaerobic treatment

Use high-load UASB, EGSB and other anaerobic reaction equipment to degrade macromolecular COD into small molecules. It can decompose COD through the metabolism of cultured anaerobic microorganisms.

2. Aerobic treatment

Decomposition of the degradation products from the anaerobic stage of small molecular organic matter, through two stages of anaerobic and itching, to solve the problem of how to remove COD in water.

However, it should be noted that the COD treated by the microbial method can generally only be reduced to a medium concentration and cannot reach the standard. In this case, environmentalists will add a COD degrading agent at the end to achieve the effect of deep removal of COD in water.

Granular COD - physical method:

There are two common methods of physically removing COD in water: flocculation and flotation.

1. Flocculation method

Flocculation is the addition of chemical flocculants to water, and the particles in the water are agglomerated and settled down through the adsorption, bridging, and electrical neutralization of the flocculant. It should be noted that, by removing COD sewage in this way, there will be sediments.

2. Air flotation

The effect of air flotation is the same as that of flocculation, except that after some sewage is added with flocculant, the tendency of flocs to float is greater than that of sedimentation. Therefore, the flocs are transported to the surface using air flotation and then scraped off with appropriate equipment.

Water quality COD detection methods mainly include dichromate reflux method, potassium permanganate method, spectrophotometry, rapid digestion method and rapid digestion spectrophotometry. . If the concentration is not high and the amount of water is not large, it is recommended to use the COD degrading agent directly.