Do you know the role of magnesium sulfate in treating sewage and wastewater?
In the field of environmental protection, magnesium sulfate is used directly as a sewage treatment agent or as a raw material for the production of sewage treatment agent for industrial sewage treatment. Taking the treatment of printing and dyeing wastewater as an example, the role of magnesium sulfate in treating sewage and wastewater is introduced in detail.
The pollutants in printing and dyeing wastewater are mainly the dirt, salts, oils and fats on textile fibers such as cotton wool, as well as various slurries, dyes, surfactants, auxiliaries, acids, alkalis, etc. , These are a type of industrial sewage that is extremely harmful to the environment, with large discharge, high chroma, and difficult degradation of organic matter, which brings great difficulties to wastewater treatment. It is difficult to meet the standard using conventional treatment methods. Features:
1. The amount of wastewater is large. The printing and dyeing wastewater of pure cotton and blended fabrics is 2.5-3.5m3/100m fabrics, polyester-cotton fabrics are 2-2.4m3/100m fabrics, silk fabrics are 4-6m3/100m fabrics, and worsted fabrics are 12-15m3 /100 fabrics, the amount of waste water is quite large.
2. The water quality is complex, and the wastewater contains residual dyes, pulp, additives, fiber impurities and inorganic salts. Nitro and amine compounds and heavy metal elements such as copper, chromium, zinc and arsenic in the dye structure have great biological toxicity.
3. Printing and dyeing wastewater has high organic content, collectively referred to as the adjusted COD of 800-1200mg/L. The composition of COD includes residual dyes, auxiliaries, slurry, etc., and the COD of lye wastewater is as high as 100g/L.
4. The biodegradability is poor, and the BOD/COD value of wastewater is very low, generally around 0.2. Therefore, it is necessary to take measures to improve the B/C value to facilitate biochemical treatment.
5. Wastewater contains a large amount of additives and surfactants. In addition to being difficult to biodegrade and pollute the water, foam is generated during biological treatment and aeration, which hinders oxygenation.
Conclusion: The use of MgSO4·7H2O as a flocculant to treat acid dye wastewater can effectively remove water-soluble acid dyes. After treatment, the chromaticity and CODCr reach 99% and 78.9% respectively, and the decolorization rate can reach more than 98%, and the production can be guaranteed. The continuity of the production process greatly improves the production efficiency and reduces the labor intensity, and also reduces energy consumption and production costs. After many printing and dyeing users use magnesium sulfate to treat waste liquid sewage, the effect is satisfactory.
