Metal surface coating wastewater reuse system

Abstract

The invention discloses a metal surface coating wastewater reuse system comprising a physicochemical treatment unit, a hydrolysis acidification tank, an MBR tank, a first biological aerated filter tank, an activated carbon filter, a reverse osmosis system and a second biological aerated filter tank; sewage is treated by the physicochemical treatment unit to remove heavy metal ions, phosphate ionsand suspended solids in the sewage; effluent of the physicochemical treatment unit flows into the hydrolysis acidification tank for degradation treatment; effluent of the hydrolysis acidification tankflows into the MBR tank for purification treatment; effluent of the MBR tank flows into the first biological aerated filter for purification treatment; effluent of the first biological aerated filterflows into an activated carbon filter to remove residual chlorine, effluent of the activated carbon filter flows into the reverse osmosis system to be purified, produced water of the reverse osmosissystem is reused, and a concentrated solution of the reverse osmosis system flows into the second biological aerated filter to be purified. The system has the advantages of simple process, reduction of medicament investment, prolonging of the service life of an RO membrane and reduction of enterprise cost.

Description

technical field [0001] The invention relates to the technical field of wastewater treatment, in particular to a metal surface coating wastewater recycling system. Background technique [0002] Metal surface coating wastewater contains a large amount of organic substances that are difficult to degrade and other pollutants. After treatment, it can be reused in the production process, which can save water and reduce enterprise costs. More importantly, it can avoid environmental pollution and bring harm to human beings. The existing treatment process is: first, solid-liquid separation is carried out through physical and chemical precipitation, and then the organic matter is decomposed into water and carbon dioxide through the degradation of microorganisms in the aerobic tank. Add a polymer flocculant (PAM) to ensure the quality of the effluent water and realize solid-liquid separation; then filter through the ultrafiltration (UF) system, and then enter the reverse osmosis (RO) s...

AI Technical Summary

Problems solved by technology

Since the wastewater needs to be reused through the RO reverse osmosis system, the sludge concentration in the aerobic tank is low, the biological treatment degradation is not complete, and the effluent of the biological sedimentation tank contains high organic matter and suspended matter, which needs to be passed through ultrafiltration (UF) System filtration treatment can enter the RO reverse osmosis system, the process is complicated, the treatment process is long, and the operating cost is high

In particular, when the polymer flocculant (PAM) is added to the biological sedimentation tank, the residual polymer organic matter in the effluent is high, which will cause frequent blockage of the UF membrane and frequent chemical washing, especially PAM will cause permanent membrane blockage, and the UF effluent will pass through The amount and effect will decrease, and at the same time, it will cause the clogging of the RO membrane, which requires frequent chemical cleaning, and the service life of the RO membrane is usually only about 1 year before it needs to be completely replaced; resulting in high operating costs for the reuse water system and frequent maintenance of chemical cleaning

In addition, the concentrated water produced by the RO system can only be discharged up to the standard after being treated by a chemical advanced oxidation process. A large amount of chemicals need to be added, the treatment process is complicated, there are many supporting equipment, and the energy consumption is high.

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