Methods of treating sewage

The aqueous formula of ferric chloride is (FeCl3·6H20).

Characteristics: The formed alum has good precipitation, the treatment of low temperature water or low turbidity water effect is better than aluminum salt, the suitable pH range is wider, but the color of the treated water is higher than that of the aluminum series, and it is corrosive.

The molecular formula of ferrous sulfate is (FeS04·H20).

Features: The dissociated Fe2+ can only generate the simplest mononuclear complex, which is not as good as the coagulation effect of the trivalent iron salt.

The molecular formula for aluminum sulfate is Al2(S04)3

Features: Aluminum sulfate is the most used flocculant in wastewater treatment, easy to use, good flocculation effect;

Disadvantages: When the water temperature is low, hydrolysis is difficult, and the floc formed is looser; It has a narrow range of effective pH values.

Mingiso (Al2(S04)3·K2S04.24H20) is similar to aluminum sulfate.

Second, polymer inorganic flocculant

Inorganic polymer flocculant is the most used flocculant with high coagulant effect and low price. According to the different ionic degree can be divided into cationic type and anionic type

Cationic type: polyaluminum chloride, polyaluminum sulfate, polyaluminum phosphate, polyferric sulfate, polyaluminum ferric chloride, etc.

There are few varieties of anionic inorganic flocculants, and the more mainstream in 2013 is polymeric silicic acid.

Treatment agent:

There are many kinds of sewage treatment agents, the most commonly used is flocculant, flocculant can be divided into inorganic flocculant and organic flocculant.

Inorganic flocculant

Inorganic flocculants are divided into low molecular weight and high molecular weight inorganic flocculants according to the size of molecular weight.

Low molecular weight inorganic flocculant

The most widely used are iron series and aluminum series metal salts. The mainstream of the market are aluminum chloride, ferric chloride, ferrous sulfate and aluminum sulfate.

Aqueous formula of ferric chloride (FeCl3·6H20)

Characteristics: The formed alum has good precipitation, the treatment of low temperature water or low turbidity water effect is better than aluminum salt, the suitable pH range is wider, but the color of the treated water is higher than that of the aluminum series, and it is corrosive.

The molecular formula of ferrous sulfate is (FeS04·H20).

Features: The dissociated Fe2+ can only generate the simplest mononuclear complex, which is not as good as the trivalent iron salt.

The molecular formula for aluminum sulfate is Al2(S04)3

Features: It is the most used flocculant in wastewater treatment, easy to use, good flocculation effect, when the water temperature is low, hydrolysis is difficult, the formation of floc is loose, its effective pH range is narrow.

The action mechanism of Mingiso (Al2(S04)3·K2S04.24H20) is similar to that of aluminum sulfate.

Polymer inorganic flocculant

Inorganic molecular flocculant is the most mainstream inorganic flocculant with high coagulant effect and low price. The varieties of inorganic polymer flocculants can be divided into cationic type and anionic type according to different ionic degree

Cationic type: polyaluminum chloride, polyaluminum sulfate, polyaluminum phosphate, polyferric sulfate, polyferric chloride, polyferric phosphate, polyferrous and so on.

cpolyaluminium chloride (cpolyaluminium chLoricle) is a new type of mainstream inorganic polymer flocculant. Due to its higher efficacy than traditional inorganic chemicals in water treatment, it will be rapidly developed and widely used.

There are fewer varieties of anionic inorganic flocculants, and the more mainstream is polymeric silicic acid in 2013.

Organic flocculant

Organic flocculants are divided into ionic and non-ionic types.

Ionic organic flocculants can not only change the surface charge of particles, but also act as bridging chains to cause flocculation. Such as polyacrylamide (also known as 3 flocculants). Used to accelerate the rapid settlement of thickening concentrate. This reduces the water content of the concentrate and reduces metal loss.

Organic flocculants are generally relatively large molecular weights, usually tens of thousands, hundreds of thousands, or even millions, so adding a small amount can play a bridge chain role.