Evaporation, concentration and recycling zero-discharge system for phosphating wastewater treatment

Abstract

The invention provides an evaporation, concentration and recycling zero-discharge system for phosphating wastewater treatment. The evaporation, concentration and recycling zero-discharge system for phosphating wastewater treatment comprises a phosphating and washing system, a phosphating wastewater treatment system, a reclaimed water recycling evaporation system and an RO treatment system. Phosphatization wastewater is subjected to three times of water washing through the phosphatization water washing system, after water washing, the wastewater is discharged out of the water tank through an overflow port and enters the phosphatization wastewater treatment system, the phosphatization wastewater treatment system is used for removing heavy metal ions and phosphate ions in the wastewater to obtain reclaimed water, a solution in the reclaimed water recycling box enters the evaporator through a guide pipe to be evaporated and concentrated, condensate water from the evaporation part is discharged into a condensate water tank, concentrated water permeated out of a primary reverse osmosis system and a secondary reverse osmosis system in the RO treatment system is discharged into the concentrated water collecting tank, evaporation continues to be conducted through the evaporator, and closed-loop circulation is completed.

Description

technical field [0001] The invention relates to the technical field of wastewater treatment, in particular to a zero-discharge system for phosphating wastewater treatment by evaporation, concentration and reuse. Background technique [0002] Phosphating is a process for metal surfaces; phosphating-treated metal materials and their products form an immersion phosphate film on the surface, which has good bonding ability, wear resistance and adhesion to paint with the metal substrate. . Phosphating is divided into simple phosphating and high-demand special phosphating. Simple phosphating is the use of phosphoric acid, sulfuric acid and nitric acid; and the special phosphating agent powder products with high requirements produce more sludge. Phosphating wastewater refers to the wastewater generated during the treatment of metal surfaces. It mainly includes alkali washing emulsification wastewater, rinsing wastewater, pickling waste liquid and phosphating waste liquid and othe...

AI Technical Summary

Problems solved by technology

Phosphating wastewater contains a large amount of phosphate, zinc ions, acid-base substances and organic matter; depending on the production process, sometimes it also contains a certain amount of heavy metals such as nickel ions, copper ions or lead ions, and surfactants. Difficult to handle

[0003] At present, the treatment of this kind of wastewater is mainly based on physical and chemical methods, that is, according to different treatment objects and treatment purposes, combined processes such as distributed precipitation, air flotation, filtration, activated carbon adsorption and membrane separation technology are used. The effect on the treatment of phosphating wastewater Poor, resulting in the treatment of phosphating wastewater can not achieve the effect of discharge

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