Wastewater Treatment Magnesium Hydroxide

Molecular formula of magnesium hydroxide: Mg(OH)2

Molecular weight: 58.32(international standard)

Regular structure: colorless hexagonal crystal Modified magnesium hydroxide products are mainly used in PE, PP, PVC, PS, etc.
HIPS, PA, PBT, unsaturated polyester, epoxy resin, rubber, paint flame retardant filler, chemical industry, environmental protection and other industrial fields; used in plastics, rubber and other high polymer materials excellent retardant and filler, in environmental protection as flue gas desulfurizer, can replace burning and lime as acid-containing wastewater neutralizer; used as oil additives, anti-corrosion and desulfurization for electricity. Subindustries, thermal insulation materials and other magnesium salt products.

What is the effect of using magnesium hydroxide in sewage treatment?

As we all know, magnesium hydroxide is mainly used as a flame retardant, but many people do not know that magnesium hydroxide can also be used for sewage treatment, especially in the treatment of acidic wastewater.

Acid Wastewater Treatment

Acid-containing wastewater and waste liquid mainly come from the acid-containing wastewater and waste liquid discharged from the pickling workshops of machinery, electrical appliances, tools and other factories. In addition to sulfuric acid, hydrochloric acid, nitric acid, hydrofluoric acid, etc., the waste acid also contains a large amount of metal ions , The traditional acid wastewater treatment method is usually to use lime milk or limestone, soda ash, caustic soda and other alkaline substances to neutralize. In order to ensure the complete precipitation of metal ions, there is often a problem that the pH is difficult to control. The use of magnesium hydroxide for sewage treatment is better than caustic soda or limestone, because in the biochemical treatment of wastewater, it is necessary to ensure a suitable pH value, nutritional conditions and alkalinity, and it is difficult to control its alkalinity with caustic soda or limestone. Magnesium oxide has a wide range of applications as an acidic wastewater treatment agent, and it is also suitable for acid-containing waste gas (SO₂, HCl₂, NO₂).

Heavy metal removal

Among the heavy metal wastewater, electroplating wastewater is more typical. The water quality of electroplating wastewater is complex and its composition is not easy to control. The heavy metal ions such as chromium, nickel, copper, zinc, gold, silver and cyanide contained in it are relatively toxic. Magnesium hydroxide has a large specific surface area and strong adsorption capacity. It is easy to absorb and remove heavy metal ions that are harmful to the environment from various industrial waste liquids. Magnesium hydroxide can be used alone or in combination with other agents. The treatment effect is better than that of most existing flocculants. Compared with calcium hydroxide, it also has the characteristics of small volume of sludge produced, compact structure and easy separation and filtration. While neutralizing the acid in wastewater, magnesium hydroxide can precipitate chromium, nickel, and cadmium ions, and further remove ions in wastewater through the adsorption of magnesium hydroxide. The removal rate is as high as 98%. The treated hydroxide Magnesium can also be used for wastewater treatment many times after light burning.

Dephosphorization and deamination of wastewater

Excessive nitrogen and phosphorus content in wastewater will cause eutrophication of the water body and promote the excessive growth of algae, causing hypoxia in fish and endangering the survival of marine organisms. Therefore, phosphorus and nitrogen removal should generally be carried out before wastewater is discharged. Although the cost of magnesium hydroxide for phosphorus and ammonia removal is slightly higher, the phosphorus removal rate is above 90%.

Dye wastewater decolorization

Printing and dyeing wastewater has a large volume, a wide area, complex components, and deep color. It mainly contains dyes, dyeing auxiliaries, size, fiber impurities, and inorganic salts, among which the pollution of dyes is the most serious. Among all kinds of dyes, reactive dyes are highly water-soluble and difficult to biochemically degrade, and their COD removal and decolorization are extremely difficult. Magnesium hydroxide is used for decolorization treatment of dyeing wastewater, which has a good decolorization effect, and the decolorization rate is over 98%. aluminum iron.