Water treatment using electrodeionization: Ultrapure water for the beverage industry

At Makkah Water in Saudia Arabia, a new wastewater treatment system from Krones will go into operation in mid-2021. This Hydronomic contains a first – with a total dissolved solids (TDS) value of less than 0.1mg per litre, the resulting water is claimed “purer” than any other in the beverage industry. The combination of the Krones Hydronomic and an electrodeionization (EDI) module makes it possible. Dirk Scheu, sales specialists for water treatment solutions at Krones, rediscovers this system and develops it further for the Makkah Water project.

Hydronomic water treatment system.

How does electrodeionization (EDI) work?
Dirk Scheu:
EDI removes ions and ionizable substances from water to the greatest extent possible, almost completely demineralising the water. The EDI module combines a continuously regenerating mixed-bed ion exchanger with ion-selective membranes. Basically, the water is split, then the ions that need to be removed are separated out, and the remaining H+ and OH- ions react to form the purest possible, deionized water.

How did Krones combines its Hydronomic water treatment system with EDI technology?
Before the water reaches the EDI module, two Hydronomic systems do important preparation work. First, the water is ultra-filtrated by the Hydronomic UF, which uses membrane technology with hollow fibres. Then, in the reverse osmosis (RO) module, mineral salts in the water are removed down to a TDS value of 5-10mg per litre.

The next step is EDI, which further reduces the TDS considerably, to less than 0.1mg per litre. This ultrapure water is often less conductive than the target of 0.1 microsiemens per centimetre. The completely demineralised water is ideal for remineralization according to the customer’s recipe in a Hydronomic MDS.   

The full article is published on the latest Water & Wastewater Asia Sep/Oct 2021 issue. To continue reading, click here.