Treatment device and method for recycling reclaimed water in effluent from secondary sedimentation tank

Abstract

The invention belongs to the technical field of wastewater treatment and specifically relates to a treatment device and method for recycling reclaimed water in effluent from a secondary sedimentationtank. According to the invention, EDR (Electrodialysis Reversal) is adopted for desalinizing the effluent from the secondary sedimentation tank generated during the process of paper making; the removal rate of sulfate radicals and chloride ions in water can reach 90% or above; the recycling rate of water can reach 75% or above; EDR, ultrafiltration and other technologies are adopted for greatly improving the processing capacity for water of the secondary sedimentation tank; the equipment is simply operated and easily used; the energy consumption is lower; in addition, no more infrastructures need be established; and meanwhile, the EDR technology only has a migrating function for salts in water and cannot migrate COD substances, so that the advanced oxidation treatment process for concentrated water can be avoided, and therefore, the subsequent evaporation treatment can be conveniently performed, and the production cost can be greatly saved; the treated fresh water can be recycled, so that the discharge of papermaking wastewater can be greatly reduced, and meanwhile, the use ratio of water resource is increased; not only is the clean and environment-friendly treatment realized, butalso the original treatment process is greatly simplified and the overall wastewater treatment cost is lowered.

Description

technical field [0001] The invention belongs to the technical field of wastewater treatment, in particular to a method for advanced treatment of secondary sedimentation tank water. Background technique [0002] Membrane separation technology is an emerging fluid separation technology, which can be classified into pressure-driven membrane and electric-driven membrane according to the driving force. Pressure-driven membranes can be divided into microfiltration, ultrafiltration, nanofiltration, and reverse osmosis according to the molecular weight cut-off. The molecular weight cut-off of ultrafiltration ranges from 10 million to 1 million. It is often used in pretreatment processes. The main intercepted substances are suspended solids, organisms, colloids, bacteria, viruses and other impurities in water, which can effectively reduce turbidity, COD, Water quality indicators such as TOC and SDI. The electrically driven membrane has selective permeability to the ions in the wate...

AI Technical Summary

Problems solved by technology

The activated sludge method in the aerobic method is widely used, and its operating cost is relatively low. The secondary sedimentation tank at the end of the process has a large amount of water but the water quality is unstable, and it can only meet the discharge standard. Further advanced treatment is still required for water quality reuse.

[0005] In the prior art, the papermaking wastewater and printing and dyeing wastewater are discharged directly after being treated up to the standard, or the wastewater in the papermaking industry is only treated to meet the requirements of pulping production water, which is a serious waste of resources

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