Common water treatment agents

Pharmaceutical Introduction:
In water treatment processes, in order to improve water treatment efficiency or maintain equipment, it is necessary to add an appropriate amount of chemicals to improve water quality. Below are several commonly used water treatment agents:

Coagulant (floc):
The commonly used coagulants include inorganic polyaluminum chloride (PAC), polyferric sulfate (PFS), and organic polyacrylamide (PAM). According to the experimental results, adding different amounts of coagulants can cause charged colloids in water to become unstable and grow, condensing into large particles. Then, through the action of gravity, the large particles in the water can deposit in the sedimentation area of the equipment, or be intercepted by filter media to reduce suspended solids and turbidity, making the produced water clear.

bactericide:
Fungicide is a type of chemical agent with strong oxidizing or reducing properties, which kills active organisms such as bacteria, viruses, algae, and organic matter in water through its oxidizing or reducing properties, thereby preventing the growth of bacteria and other active organisms in water treatment equipment and polluting water quality. At present, the commonly used bactericides in water treatment processes are oxidizing hypochlorous acid, and a small amount of reducing bactericides are also added.

Adsorbent:
Commonly used fungicides include sodium hypochlorite and organic polyacrylamide (PAM). Adding different amounts of coagulants based on experimental results can cause charged colloids in water to become unstable and grow, condensing into large particles. Then, through gravity, the large particles in the water can be deposited in the sedimentation area of the equipment, or intercepted by filter media to reduce suspended solids and turbidity, making the produced water clear.

Scale inhibitor:
Scale inhibitor is a type of chemical agent that can disperse insoluble inorganic salts in water, prevent or interfere with the precipitation and scaling of insoluble inorganic salts on metal surfaces, and maintain good heat transfer performance of metal equipment by preventing the growth of insoluble salt crystals. Organic phosphorus, polycarboxylate, and composite scale inhibitors are commonly used in reverse osmosis systems to effectively prevent membrane surface scaling caused by concentration polarization, remove scale, and prevent scale formation. It is also used in industrial circulating water to increase concentration ratio, reduce pollution, and improve water utilization efficiency, generally saving more than 60%, which is in line with China's new energy conservation and emission reduction policies.

Reducing agent:
Reducing agent is a type of chemical agent with reducing properties. It is mainly used in membrane systems such as reverse osmosis. Due to the addition of oxidants during water treatment, active chlorine is produced, which can cause irreversible oxidation of the reverse osmosis membrane and lead to a decrease in membrane flux. Adding an appropriate amount of reducing agent can effectively ensure that the membrane in the membrane system is not oxidized. At present, commonly used reducing agents in water treatment include sodium bisulfite and hydrogen peroxide.

Acid solution:
Acid solution is a substance that can hydrolyze and ionize hydrogen ions, mainly used to adjust the pH of water, dissolve some, and also serve as a regenerant for cation exchange resins. The commonly used inorganic acid solutions for water treatment include hydrochloric acid and sulfuric acid, while organic acid solutions include citric acid.

Alkali solution:
Alkali solution is a substance that can hydrolyze and ionize to produce hydroxide ions. It is mainly used to adjust the pH of water and also serves as a regenerant for anion exchange resins. The commonly used inorganic alkaline solutions for water treatment include sodium hydroxide and calcium hydroxide.