There are many types of treatment chemicals used in wastewater treatment processes, including coagulants, flocculants, disinfectants, pH adjusters, and oxygen scavengers.
Coagulants are used to destabilize and clump together suspended particles in wastewater, making them easier to remove. Examples of coagulants include aluminum sulfate (alum), ferric chloride, and poly aluminum chloride (PAC).
Flocculants help the coagulated particles to form larger clumps, making them easier to settle or filter out of the wastewater. Examples of flocculants include polymers such as polyacrylamide, polyethylene oxide, and poly-diallyl dimethylammonium chloride.
Disinfectants are used to kill bacteria and viruses in the treated wastewater before it is discharged. Examples of disinfectants include chlorine, ozone, and ultraviolet (UV) light.
pH adjusters are used to controlling the pH level of the wastewater, as some treatment processes are pH-sensitive. Common pH adjusters include sulfuric acid and sodium hydroxide.
Oxygen scavengers are used to remove excess oxygen from the wastewater, as high levels of oxygen can interfere with certain biological treatment processes. Examples of oxygen scavengers include sodium sulfite and sodium bisulfite.
Treatment chemicals are typically dosed into the wastewater in precise amounts using specialized equipment such as metering pumps, dosing tanks, and control systems to ensure effective treatment and minimal environmental impact.