Electrode deionization, also known as packed bed electrodialysis (EDI) or (CDI), is a water treatment technique that combines anion and cation exchange resin between the septums of the electrodialyser and combines the electrodialysis with ion exchange. It is considered one of the revolutionary innovations in the field of water treatment technology.
EDI advantages:
EDI devices are used in the reverse osmosis system, replacing the traditional hybrid ion exchange technology (MB-DI) to produce stable deionized water. EDI technology and hybrid ion exchange technology compared to the following advantages:
1, small footprint, omitted mixed bed and regeneration device;
2. Continuous production of water, high water quality, and mixed bed in the resin near the failure of water quality will be worse;
EDI device is a continuous water purification process, so its product water quality and stability, the resistivity is generally 15MΩ · cm, up to 18MΩ · cm, to achieve the indicators of ultra-pure water. The water purification process of the mixed bed ion exchange facility is intermittent, and after its regeneration, the water quality of the product is higher, and before the next regeneration, the water quality of the product is poor.
3. Low operating costs, renewable only power consumption, no acid, save material costs;
EDI equipment operating costs, including electricity consumption, water consumption, pharmaceutical fees and equipment depreciation costs, eliminating the need for acid and alkali consumption, renewable water, wastewater treatment and sewage discharge costs.
In terms of power consumption, EDI device about 0.5kWh / t water, mixed bed technology of about 0.35kWh / t water, the cost of electricity consumption in the power plant is more economical, you can use the price of plant electricity accounting.
In terms of water consumption, the EDI plant has a high water production rate and does not require reclaimed water. Therefore, the operating cost is lower than that of the mixed bed in this respect.
There is little difference between the cost of pharmacy and equipment depreciation.
In general, in the operating costs, EDI equipment tons of water running costs around 2.4 yuan, the conventional mixed bed tons of water running costs around 2.7 yuan, higher than the EDI device. As a result, the cost of multiple investments in EDI devices is fully recoverable within a few years.
4. Significant environmental benefits, increased operational safety;
EDI is environmentally friendly technology, ion exchange resin without acid, alkali chemical regeneration, save a lot of acid, alkali and cleaning water, greatly reducing the labor intensity. More importantly, no waste acid, waste lye discharge, non-chemical type of water treatment system, it does not need acid, alkali storage, treatment and no waste water emissions, so it is a new user with a special attraction.
Third, technical performance
EDI component operation results depend on a variety of operating conditions. The following are the minimum conditions to ensure the normal operation of EDI. In order to make the system run better, the system design should be appropriate to improve these conditions.
EDI influent indicators
In order to prevent fouling of the device, to reduce its operating life, EDI water quality have certain requirements, the general use of RO permeate as water.