Ultra High Purity Water Systems: How Do They Work?

Ultra high purity water (UPW), sometimes referred to as ultrapure, is water of the highest quality, treated in three stages to remove all organic matter and dissolved gases with a specially designed system. Depending on the industry, the UPW treatment system focuses on removing detrimental particles and matter. Read on to learn more about ultra high purity water and the purification system involved.

What is Ultra High Purity Water?

UPW is used in many industries, but the main producers and consumers of UPW include semiconductor, solar photovoltaic and pharmaceutical plants. Each industry maintains its own definitive standards of purity for their UPW supply. As an example, semiconductor production utilizes UPW to clean products. Any particles in the UPW may get left behind and contribute to the sudden failure of the microchip over time. Pharmaceutical production uses it as an ingredient in human and animal medications. The water must be completely purified of all toxins, viruses and bacteria.

What are the Steps of Purification?

All UPW systems are highly dependent on the source water’s quality. The treatment options are largely dictated by the level of purification already achieved. However, most every purification system follows these three steps:

1. Pretreatment: The main goal of pretreatment is to generally purify the water. First, the water goes through one or more stages of reverse osmosis and demineralization. If it contains a high level of suspended solids and organic particles, filtration methods such as multi-media filtration, automatic backwash filtration and ultrafiltration are applied. Multi-media filtration has the ability to extract particles as small as five microns.
2. Primary: Next, ultraviolet light is used to effectively destroy total organic carbons (TOCs) to reduce the water to its purest form. Exposure to UV light initiates a chemical reaction. High levels of UV cause water molecules to dissociate and create hydroxyls. The hydroxyls bond easily with TOCs. When they combine, they form new water and carbon dioxide molecules and the original TOCs are gone. UV light can also break apart TOCs without a chemical reaction with water, or ionize the TOCs so they can be destroyed by a deionization system in the next stage of treatment. At the primary treatment stage, gases are also removed.
3. Polishing: Finally, the UPW system begins to finalize the treatment process. This stage involves membrane degasification, the removal of dissolved oxygen and carbon dioxide. The water will also pass through ultrafiltration membranes to ensure particle size standards are met. If the industry requires a high temperature, the UPW product is heated before passing on to the point of use.

New technologies involving UPW recycling and reuse are constantly explored. Talk to a professional at Innovative Water Treatment for specific advice related to your industry and for guidance putting together a water management plan and installing an ultra high purity water treatment system.