Printing and dyeing wastewater is a kind of industrial wastewater produced by textile industry. It is characterized by high concentrations of organic matter, dyes and other pollutants. This type of wastewater can be a major environmental problem because it can pollute waterways and contribute to the spread of disease.
A number of methods are available to treat dyeing wastewater, including physical, chemical and biological methods. Physical treatment methods include sedimentation and filtration. Chemical treatment methods include flocculation, coagulation and oxidation. Biological treatment methods include anaerobic digestion and aerobic digestion.
Flocculation is a process used to coalesce small particles into larger particles or flocs. Flocculation is often used in combination with other treatment methods, such as sedimentation and filtration. Flocculants are substances that are added to the wastewater to promote flocculation.
The choice of treatment method will depend on the specific characteristics of the wastewater. For example, if the wastewater contains a high concentration of dyes, then chemical treatment may be an option. If the wastewater has a high concentration of organic matter, then biological treatment may be a better choice.
Water treatment chemicals for printing and dyeing wastewater treatment
There are many different water treatment chemicals that can be used to treat printing and dyeing wastewater. Some of the common water treatment chemicals are:
Alum: Alum is a metal salt that is commonly used as a coagulant in wastewater treatment. Alum is effective in removing dissolved organic matter and other pollutants from wastewater.
Ferric chloride: Ferric chloride is a commonly used water treatment chemical for dyeing wastewater treatment, its function is to oxidize organic substances in wastewater into inorganic substances, so as to remove harmful substances. Ferric chloride is usually used in the intermediate treatment of printing and dyeing wastewater treatment.
Potassium permanganate: Potassium permanganate is a strong oxidizing agent, which can effectively remove organic matter, pigment and other harmful substances from wastewater and has good oxidizing performance. Potassium permanganate is usually used in the post-treatment of printing and dyeing wastewater treatment.
Polymeric aluminum chloride: Polymeric aluminum chloride is a commonly used water treatment agent for printing and dyeing wastewater treatment. Its function is to make the suspended and colloidal substances in wastewater coalesce into large particles, so as to remove harmful substances. Polymeric aluminum chloride is usually used in the intermediate treatment of printing and dyeing wastewater treatment.
Polydimethyldiallylammonium chloride: This is a cationic polyelectrolyte, usually used as a flocculant in wastewater treatment. It has a positive charge and can destabilize and flocculate suspended particles and water-soluble substances containing negatively charged genes in water through electrical neutralization and adsorption bridging, and has obvious effects in decolorization, sterilization and removal of organic matter. Poly(dimethyldiallylammonium chloride) as flocculant has the characteristics of low dosage, large floc, fast sinking speed and low residual turbidity, and low sludge generation.
Cationic polyacrylamide: It is a linear polymer compound, which can form hydrogen bonds with many substances by affinity and adsorption due to its various active groups. It can be used in a wide range of pH values. It mainly flocculates negatively charged colloids and has the functions of turbidity removal, decolorization, adsorption and bonding, which is suitable for the treatment of wastewater with high organic colloid content in dyeing and paper industries.
Biological bacterium agent: Biological bacterium agent is a kind of water treatment agent for dyeing wastewater treatment that uses the metabolic effect of microorganisms to remove organic matter in wastewater. Biobacterial agent is usually used for post-treatment in printing and dyeing wastewater treatment.
Activated carbon: Activated carbon is a porous adsorbent with high porosity, which can effectively remove organic matter, pigment, chlorine, fluorine and other harmful substances from wastewater and has good adsorption performance. Activated carbon is usually used for pretreatment and post-treatment in printing and dyeing wastewater treatment.
In a word, different water treatment chemicals for printing and dyeing wastewater treatment have different roles and application scope, and choosing suitable chemicals can effectively remove harmful substances in wastewater and reach the discharge standard.