Principle and application range of ferrous sulfate wastewater treatment

Ferrous sulfate, also known as alum, is a light green, blue-green or yellowish crystal or particle, odorless and tasteless. Its chemical formula is FeSO4 · 7H2O, the relative molecular weight is 278.02, the relative density is 1.898, the melting point is 64 ℃, six crystal water are lost at 90 ℃, and all crystal water is lost at 300 ℃. It is soluble in water and glycerin, slightly soluble in alcohol, and easily oxidized to yellow or rust color in wet air.

Ferrous sulfate is an acidic ferric salt with the function of flocculation and decolorization. Many wastewater treatment (such as printing and dyeing wastewater) uses ferrous sulfate for decolorization and dephosphorization. Ferrous sulfate can quickly combine with suspended solids in water for sedimentation, which has the functions of sterilization, decolorization and removal of Cod. Because ferrous sulfate belongs to acidic substances, if the treated wastewater belongs to alkaline wastewater, adding a certain amount of ferrous sulfate in the water can achieve the purpose of regulating the pH value of alkaline wastewater.

Ferrous sulfate has a very wide range of use, which is not only used more in industrial production, but also common in daily life. Besides, ferrous sulfate is also a very good sewage treatment agent. At present, ferrous sulfate is commonly used as flocculant and precipitator in water treatment. Reducing agent, etc.

Ferrous sulfate has a very good flocculant in sewage treatment. Compared with other flocculants, ferrous sulfate has a fast settling speed, and alum flowers are cut and compacted. It has a good decolorization effect on the sewage of printing and dyeing and textile industries. Ferrous sulfate is less corrosive in water treatment, has little impact on pipeline equipment, does not need to change water treatment process when using, and has low price. It is one of the most important sewage flocculants at present.

Ferrous sulfate can also be used as a good precipitator to produce water insoluble sediment through the reaction of ferrous sulfate with sulfide, phosphate, etc. The precipitation of ferrous sulfate is mainly used in the treatment of chemical wastewater, printing and dyeing wastewater, etc. Ferrous sulfate is also a good reducing agent. Ferrous ions in ferrous sulfate are very easy to be oxidized, which is also the reason for the reducibility of ferrous sulfate. The reducibility of ferrous sulfate can reduce hexavalent chromium in electroplating wastewater to trivalent chromium, and can also replace heavy metal ions in many wastewater.

Application range of ferrous sulfate

1. It is used for sewage treatment as a coagulant with good decolorization capacity;

2. As a precipitator, it can remove sulfide, phosphate, etc;

3. Used for the reduction of hexavalent chromium in electroplating plants;

4. As a nutrient for microorganisms in the biochemical system, it can enhance biological activity;

5. Pigments, raw materials for electronic industry, hydrogen sulfide deodorant, soil improver, industrial catalyst, etc.

Packaging, storage and transportation

25kg, 50kg woven bags, or ton bags.

Store in a dry, cool and ventilated place.

The storage stability period of drying products is 12 months, and that of high-quality products is 1 month. Qualified products must be used within one week in summer, otherwise they will turn yellow.

Decolorization mechanism of ferrous sulfate wastewater:

The coagulation treatment mechanism of ferrous sulfate is that colloidal and suspended colored particles in wastewater continuously collide with each other and agglomerate into larger flocs under the interference of ferrous ions. In fact, the decolorization mechanism of ferrous sulfate is not simple coagulation decolorization, but the complexation adsorption bridging principle of forming polynuclear complexes with dye molecules with ferrous ions as the center.