Application of magnesium sulfate in sewage treatment industry
2021-05-18 From: Shandong Mingxing Chemical Co., Ltd Browsing times:483
Magnesium sulfate is widely used in the industry. Today, we learn about the use of magnesium sulfate in the sewage treatment industry, which can coagulate and settle waste liquid and sewage, so that it can quickly reach the sewage discharge standard.
1. The amount of waste water is large. Pure cotton and blended fabrics are treated with 2.5-3.5m3/100m fabrics, polyester-cotton fabrics with 2-2.4m3/100m fabrics, silk fabrics with 4-6m3/100m fabrics and textiles with 12-15m3/100 fabrics.
2. The water quality is complex, and the waste water contains residual dyes, slurry, additives, fiber impurities and inorganic salts. Nitro and amine compounds and heavy metal elements such as copper, chromium, zinc and Arsenic in dye structure have great biological toxicity.
3. The organic matter content of printing and dyeing wastewater is high, and the adjusted COD is 800-1200 mg/L. The composition of COD is residual dyes, auxiliaries, slurry, etc. The COD of alkali liquor wastewater is as high as 100 g/L..
4. The biodegradability is poor, and the BOD/COD value of wastewater is very low, generally around 0.2, so measures should be taken to improve the B/C value in order to facilitate biochemical treatment.
5. Waste water contains a large amount of additives and surfactants, which are difficult to biodegrade and pollute the water. During biological treatment and aeration, foam is produced, which hinders oxygenation.
The principle of treating sewage and wastewater with magnesium sulfate is that magnesium salt is hydrolyzed with alkali to produce positively charged magnesium hydroxide precipitate, which strongly adsorbs negatively charged anionic dyes to decolorize dye wastewater. The effect is as follows:
Generally speaking, magnesium sulfate can effectively remove water-soluble acid dyes. After treatment, the chroma and CODCr reach 99% and 78.9%, respectively, and the decolorization rate can reach over 98%. Besides, it can ensure the continuity of production and greatly improve the production efficiency.
