PAC and PAM explain in Water Treatment Chemicals

In the field of Water Treatment Chemicals, polyaluminum chloride (PAC) and polyacrylamide (PAM) are two common flocculants, which play an important role in sewage treatment, sludge dehydration and drinking water treatment. This article will introduce the basic concepts, performance characteristics, common classification, use methods and precautions of PAC and PAM in detail.

 

I. Basic concepts of PAC and PAM

 

1. Polyaluminum chloride (PAC)

 

Polyaluminum chloride, referred to as PAC, also known as basic aluminum chloride or hydroxyl aluminum chloride. The main principle of PAC is to make colloids in sewage or sludge form large particle precipitates quickly through its hydrolysis products, which is convenient for subsequent separation and treatment. The appearance and performance of PAC are closely related to alkalinity, preparation method, impurity composition and alumina content. For example, when the basicity of pure liquid PAC is in the range of 40% to 60%, it is a light yellow transparent liquid; When the alkalinity exceeds 60%, it gradually becomes a colorless transparent liquid.

 

2. Polyacrylamide (PAM)

 

Polyacrylamide, referred to as PAM, commonly known as flocculant or coagulant. The main principle of PAM is that its molecular chain and dispersed phase pull dispersed phase particles together through mechanical, physical, chemical and other functions to form a network structure, thus playing a strengthening role. PAM is white powder, easily soluble in water, almost insoluble in benzene, ether and other general organic solvents. PAM solution is a transparent viscous liquid, non-toxic, non-corrosive, non-dangerous goods.

 

Second, PAC and PAM performance characteristics and common classification

 

Performance characteristics and classification of PAC

 

The performance of PAC is closely related to its preparation method and alkalinity. According to the different alumina content, PAC can be divided into several grades, the common are 22-24%, 26%, 28%, 30% and 32% content. Among them, 22-24% of PAC content is mainly used for industrial wastewater treatment, while 32% of PAC content is high purity iron free polyaluminum chloride, mainly used in the fine chemical industry and cosmetics manufacturing.

 

Performance characteristics and classification of PAM

 

According to the characteristics of dissociable groups, PAM can be divided into anionic, cationic and non-ionic types. Cationic PAM is mainly used for the treatment of activated sludge produced by biochemical process. The effect of anionic PAM in the treatment of positively charged sewage and sludge is better, such as the sewage treatment of iron and steel plants, electroplating plants and other industries; Non-ionic PAM has a good effect on both cations and anions, but the price is higher and it is generally not used.

 

Third, the use of PAC and PAM

 

1. Add requirements

 

When adding PAC and PAM, note the following:

 

Early stirring: In the early stage of the reaction of adding coagulant, it is necessary to increase the chance of contacting the agent with the sewage as much as possible, and increase the mixing or flow rate to improve the collision chance of particles in the water and promote floc condensation.

 

Later deceleration: To the later stage of the reaction, in order to reduce the velocity gradient, better flocculation and precipitation effects can be obtained.

 

2. Use methods

 

The concentration of PAC and PAM is generally 5%-10% for PAC and 0.1-0.3% for PAM. In summer, the dissolved concentration of PAM can be appropriately increased to 0.3-0.5%. The specific dosage should be determined according to the water quality test. In general, you need 50-100 grams of PAC and 2-5 grams of PAM per ton of sewage.

 

3. Dosing pump flowmeter setting

 

The specific amount of chemicals used has a lot to do with the concentration, properties and treatment equipment of colloids and suspended solids in sewage or sludge. The display value (LPM) on the flow meter of the dosing pump can be calculated by the formula: LPM = inlet flow rate (t/h) /60 × PPM1 concentration to be added/PPM2 concentration prepared.

 

4. Precautions

 

Preparation of liquid medicine in strict accordance with the operating procedures and instructions.

 

Ensure that the debris is not mixed into the liquid medicine, so as not to block the dosing pump, flowmeter and other equipment.

 

In order to achieve the best treatment effect, adjust the dosage in time according to the water intake and dosage notice.

 

In summary, PAC and PAM are important flocculants in the field of water treatment, and their correct use and precautions are crucial to improve the effect of water treatment. Scientific and rational use of PAC and PAM can effectively improve water quality and protect the environment.

 

Focus on water treatment, just for a healthy world! Henan AierFOk Chemical Co., Ltd. is a professional enterprise engaged in the development, production and sales of polymer flocculants. The main products are "green water clean" brand polyaluminum chloride, polyferric sulfate and other water purifiers. With an annual output of 10,000 tons, the products are sold all over the country, and actively explore the international market. The company will continue to uphold the business philosophy of "integrity, innovation and win-win", provide customers with quality products and services, and make due contributions to the society.