Laboratory EDI ultrapure water

Since the industrialization of EDI membrane reactor technology in 1986, thousands of EDI systems have been installed worldwide. They have seen significant growth in industries such as pharmaceuticals, semiconductors, power generation, and surface cleaning. They are also widely used in wastewater treatment, beverages, and microbiology.

EDI ultrapure water equipment is used after reverse osmosis systems, replacing traditional mixed-bed ion exchange (MB-DI) technology to produce stable ultrapure water.

Advantages of EDI technology and mixed ion exchange

① High water quality (up to 18 MΩ.cm);

② Simple and safe operation and convenient management;

③ No downtime due to regeneration;

④ No need for acid or alkali chemical regeneration;

⑤ Low operating costs;

⑥ Small footprint;

⑦ No wastewater discharge.

How EDI works

An EDI module sandwiches ion exchange resin between anion/cation exchange membranes to form an EDI unit. Within the EDI module, a number of EDI units are separated by grids, forming concentrate and dilute chambers. Anode/cathode electrodes are placed at each end of the unit stack. Driven by direct current, anions and cations in the dilute chamber flow through the anion/cation exchange membranes, respectively, into the concentrate chamber, where they are removed. Water passing through the concentrate chamber removes ions from the system, becoming concentrate. EDI equipment typically uses two-stage reverse osmosis (RO) pure water as the EDI feed water. RO pure water typically has a resistivity of 40-2 μS/cm (25°C). EDI pure water can have a resistivity as high as 18 MΩ.cm (25°C). However, depending on the intended use of the deionized water and system configuration, EDI ultrapure water is suitable for producing pure water with a resistivity requirement of 1-18.2 MΩ.cm (25°C).

Equipment application fields

EDI technology is widely accepted by the pharmaceutical industry, microelectronics industry, power generation industry and laboratories. It is also increasingly used in surface cleaning, surface coating, electrolysis industry and chemical industry high-purity water equipment.