Application of magnesium sulfate heptahydrate in printing and dyeing wastewater

Magnesium Sulfate Heptahydrate printing and dyeing wastewater is a type of industrial wastewater that is extremely harmful to the environment. It has a large discharge volume, high chroma, and organic matter is difficult to degrade, which brings great difficulties to wastewater treatment. It is difficult to meet the standard using conventional treatment methods. It is necessary to find a simple and inexpensive method to decolorize printing and dyeing wastewater. In recent years, research on magnesium salt method has been carried out at home and abroad. The principle of decolorization is that magnesium sulfate heptahydrate is hydrolyzed with alkali to generate positively charged Magnesium Hydroxide precipitation. It strongly adsorbs negatively charged anionic dyes and decolorizes dye wastewater. The use of magnesium sulfate to treat acid dye wastewater has a better effect, and the chroma reaches 99% after treatment. Magnesium salt method can effectively remove water-soluble acid dyes. Under suitable conditions, the decolorization rate can reach more than 98%.