The type of waste water in the roller coating room is mainly the waste solvent and coating after cleaning the roller, as well as the sediment at the bottom of the barrel after coating.
The pretreatment section is different according to the selection of surface treatment process. For example:
(1) Alkali washing degreasing reactive chemical film forming. Main wastewater types: degreasing wastewater, Phosphating Wastewater; 3) surface adjustment wastewater; 4) passivation wastewater
(2) Alkali washing degreasing acid pickling derusting reactive chemical film forming. Main wastewater types: 1) degreasing wastewater; 2) pickling wastewater; 3) Phosphating Wastewater; 4) surface adjustment wastewater; 5) passivation wastewater.
(3) Alkali wash degreasing roll coating chemical film forming. Main wastewater types: 1) degreasing wastewater; 2) roller coating chromizing wastewater.
(4) The chemical film was formed by alkali washing degreasing pickling derusting roll coating. Main wastewater types: 1) degreasing wastewater; 2) 0 pickling wastewater
3) roller coating chromizing wastewater.
The process of wastewater treatment generally adopts the principle of three-stage treatment
Stage treatment: pretreatment by mechanical or simple chemical methods to precipitate suspended solids and neutralize acid and alkali
It takes a breath:
Secondary treatment: adopt biological treatment or add coagulant to make decomposable and oxidizable organic matter absorbed by biochemical treatment; or make suspended matter and oil separated by demulsification and coagulation.
Three stage treatment: advanced treatment of refractory organic and inorganic substances by activated carbon adsorption, ion exchange, electrodialysis, reverse osmosis and chemical oxidation.