Wastewater treatment scheme of paper mill

Wright-Ryder electrodialysis process generally adopts circulation process, in which black liquor circulates through anode chamber and dilute alkali liquor circulates through cathode chamber. Under the action of DC electric field, Na+ enters the cathode chamber through the anode membrane and combines with OH- generated by electrolysis to generate NaOH to recover alkali. The black liquor in the anode chamber is constantly acidified due to the generation of H+ by electrolysis, and to some extent, most lignin is precipitated. The recovery of alkali by electrodialysis has the characteristics of simple process, convenient operation, less equipment investment and easy automation. In order to further improve the alkali recovery rate and reduce power consumption, it is necessary to improve the electrode and diaphragm.

When determining the overall process scheme of sewage treatment facilities, the following principles should be followed:

1. The selected technology must be advanced and mature, with strong adaptability to water quality changes and stable operation, which can ensure that the effluent quality meets the requirements of factory use standards and national sewage discharge standards.

2. The selected process should reduce capital investment and operating costs, save land occupation and reduce energy consumption.

3. The selected process should be easy to operate, flexible to run and easy to manage. According to the quality and quantity of influent water, the process operation parameters and operations are appropriately adjusted.

4. The selected process should be easy to realize automatic control and improve the operation management level.

5, the selected process should try to reduce the adverse effects on the surrounding environment (smell, noise, fog, etc.). ).