Wastewater treatment of surface treatment before steel drum coating

Wastewater treatment of surface treatment before steel drum coating

In order to deal with the wastewater treatment of steel drum surface treatment, we must first analyze the harmful substances contained in the wastewater, in order to determine which method to use for comprehensive treatment.

The type of waste water discharged from the surface treatment process of the steel drum is waste water such as degreasing, pickling, phosphating, and circulating water for rinsing. Its main components are acid, alkali and heavy metal salts. These sewages vary depending on the type and concentration of treatment used, so the degree of pollution to the environment is not exactly the same.

Most of the wastewater from the surface treatment of steel drums is contaminated water containing both inorganic and organic materials. It is difficult to treat and should be treated by comprehensive treatment.

Under normal circumstances, the treatment methods for surface treatment of steel drums fall into three categories. That is, physical law, chemical law, and biological law.
Physical processing methods include:

Precipitation method: Separation of precipitated material according to gravity.
Filtration: Separation of the suspension from the filtrate with a porous material.

Heat treatment method: concentration, drying, and combustion.
Aeration method: Ventilation oxidizes the reducing substance.

Adsorption method: adsorption of harmful substances, pigments, etc. with activated carbon or other adsorptive substances.

Floating method: using bubbles and solid particles to adhere.

Membrane separation method: using ultrafiltration and reverse osmosis to reduce the concentration of pollutants.

Chemical treatment methods include:

Neutralization method: neutralization treatment with acid and alkali.

Redox method: redox with sodium sulfite, air, oxygen, and the like.

Drug treatment method; using a flocculant to separate solid and liquid.

Ion exchange method: ion exchange with ion exchange resin to treat heavy metal containing wastewater.

Biological treatment methods include:

Water-spraying filter method: long-term exposure and decomposition of organisms.

Anaerobic biological treatment: Anaerobic bacteria decompose organic matter.

As an industrial enterprise, it is generally not necessary to invest too much energy here. Therefore, most steel drum companies use chemical methods for comprehensive treatment when dealing with their own industrial wastewater.