Recovery method and recovery device for ion exchange regenerated acid wastewater

Abstract

The invention relates to the technical field of wastewater recovery, in particular to a recovery method and a recovery device for ion exchange regenerated acid wastewater. The invention provides a method for recovering ion exchange regenerated acidic wastewater, which comprises the following steps: carrying out ultrafiltration treatment on the ion exchange regenerated acidic wastewater to obtain ultrafiltration produced water; under an acidic condition, carrying out acid-resistant reverse osmosis membrane treatment on the ultrafiltration produced water to obtain acid-resistant reverse osmosis effluent and first concentrated water; the acid-resistant reverse osmosis effluent is recycled; neutralizing the first concentrated water, and performing nanofiltration treatment to obtain salt solution effluent and second concentrated water; carrying out wastewater treatment on the second concentrated water, and discharging the second concentrated water after the second concentrated water reaches a discharge standard; carrying out evaporative crystallization on the effluent of the salt solution to obtain a crystallized discharged material and condensed water; the crystallization discharged material and the condensed water are directly recycled. The recovery method can effectively control the increase of the total dissolved solid content in the wastewater.

Description

technical field [0001] The invention relates to the technical field of waste water recovery, in particular to a recovery method and a recovery device for ion exchange regenerated acidic waste water. Background technique [0002] Ion exchange technology is a relatively mature technology and is widely used in many industries. At present, one of the biggest problems faced by ion exchange technology is the treatment of regenerated wastewater, especially the acidic regenerated wastewater produced by a separate cation exchange device. Taking the commonly used ion exchange desodination process in the pharmaceutical industry (including improved processes such as continuous separation and simulated moving bed) as an example, the treatment process generally adopts traditional biochemical process and Fenton process directly after neutralization, which can only meet the discharge of wastewater. As the country gradually tightens the restrictions on wastewater TDS indicators, the zero di...

AI Technical Summary

Problems solved by technology

Taking the commonly used ion exchange desodination process in the pharmaceutical industry (including improved processes such as continuous separation and simulated moving bed) as an example, the treatment process generally adopts traditional biochemical process and Fenton process directly after neutralization, which can only meet the discharge of wastewater. As the country gradually tightens the restrictions on wastewater TDS indicators, the zero discharge and resource utilization of such wastewater will become increasingly important. The existing zero discharge and resource recovery processes mainly include distillation and electrodialysis; among them, the distillation method is the first to join Sodium hydroxide is used for neutralization, and then the salt and organic matter in the wastewater are separated by a multi-small decompression evaporator, and then recovered through the salt collector, the dried liquid is incinerated, and the evaporated condensed water is reused or directly discharged up to standard , but the above method needs to be neutralized first, consumes a large amount of sodium hydroxide, and the treatment cost is very high, and after neutralization, it will cause the content of total dissolved solids (TDS) in the wastewater to increase, making subsequent treatment difficult and The complexity of the process increases, and finally the method of separating salt and organic matter through vacuum distillation requires a very large steam consumption, which greatly improves the treatment components; electrodialysis uses waste water, 0.5% NaCl and pure water After entering the electrodialysis device and powering on for a period of time, the final fresh water effluent is high COD (above 30,000 mg / L) fresh water, and the concentrated water effluent is low COD, high TDS (above 30,000 mg / L) acidic concentrated water. The fresh water can be discharged after biochemical treatment. , the electrodialysis method avoids the problem of TDS improvement caused by adding sodium hydroxide at the beginning in the distillation method, but because the use of sodium chloride solution and pure water can also cause the improvement of TDS in the waste water, recovery lower value

Images