A coagulant for treating painting wastewater and its production process

Abstract

The invention relates to a production process of a coagulant for processing coating waste water. The production process comprises the following steps: uniformly dispersing bentonite in water, wherein the concentration of bentonite dispersion liquid is 1 to 10 percent; adding aluminum salt with positive charges, uniformly stirring and dissolving the aluminum salt, then adding a silane coupling agent, and uniformly stirring; standing the mixture for reaction for 2 to 24 hours; drying a product after the reaction is ended, and crushing the product to obtain the coagulant. The coagulant which is used for processing the coating waste water and prepared by adopting the production process has a good processing effect on the coating waste water and oil-containing waste water and also has a good decoloration effect, a good oil removal effect and a good COD removal effect; moreover, the coagulant is better than original bentonite, organic polyelectrolyte and activated carbon powder. The coagulant has characteristics of rapidness in separation and settlement and small sludge amount; moreover, the addition amount is small, the operating time is short, and the adaptability to the pH value of the waste water is high.

Description

technical field [0001] The invention belongs to the field of water treatment, in particular to a coagulant for treating painting wastewater and a production process thereof. Background technique [0002] The painting of automobiles and their parts is one of the links that generate the most wastewater discharge in the automobile manufacturing process. Painting wastewater mainly comes from pre-degreasing, degreasing, surface conditioning, phosphating, passivation and other body pre-treatment processes; cathodic electrophoresis process, intermediate coating, and top coating process. The main toxic and harmful substances contained in wastewater are as follows: nitrite, phosphate, emulsified oil, surfactant, Ni 2+ , Zn 2+ , low solvent cathodic electrophoretic paint film, lead-free cathodic electrophoretic paint film, pigment, powder, epoxy resin, butanol, ethylene glycol monobutyl ether, isopropanol, dimethylethanolamine, polybutadiene resin, dimethyl Alcohol, paint, xylene, ...

AI Technical Summary

Problems solved by technology

[0003] Coating wastewater contains resin, surfactant, heavy metal ions, oil, PO 4 3- , paints, pigments, organic solvents and other pollutants, COD Cr If the value is high, it will cause serious pollution to the environment if not handled properly

For this kind of wastewater, the traditional method is to directly coagulate the mixed wastewater, the treatment effect is not ideal, the effluent quality is unstable, and it is difficult to meet the discharge standard

In particular, the spray paint wastewater contains a large amount of organic solvents soluble in water, and the direct coagulation treatment effect is very poor.