Category
  • Homes
  • > Blog
  • > Blog Details

Deionized Water: Understanding Its Purification and Uses

Deionized water is a type of p...

Deionized Water: Understanding Its Purification and Uses

Deionized water is a type of purified water from which ions have been removed using a process called ion exchange. This method of purification strips the water of dissolved mineral salts, including common ions such as sodium, calcium, iron, and copper. By removing these charged particles, deionized water becomes highly pure, with a neutral pH, no electrical charge, and a high resistivity, making it a superior choice for applications where the presence of ions could be detrimental.

Its purity makes deionized water especially valuable in environments where chemical reactions are sensitive to ionic contaminants, such as in laboratories and manufacturing processes. In the medical field, it is instrumental in creating a sterile environment for procedures. However, while it is ideal for such technical and industrial uses, deionized water is not generally recommended for human consumption over an extended period due to its lack of minerals, which are beneficial for health.

A glass of water macro shot

Chemical Properties

Deionized water, known for its high purity, exhibits unique chemical properties essential for various applications across industries. It is especially valued in contexts where the presence of ions could lead to interference or undesirable reactions.

Purity Levels

Deionized water is characterized by its lack of mineral ions, such as sodium, calcium, and chloride, which are commonly found in tap water. The process removes positively charged cations and negatively charged anions, resulting in water with extremely low levels of dissolved solids.

Conductivity

Due to its minimal ionic content, deionized water has a very low electrical conductivity. This property makes it an excellent insulator, which is why it's often used in situations where electrical interference needs to be minimized.

pH Value

The pH of deionized water is typically neutral, around 7.0. However, it is important to note that because deionized water readily absorbs carbon dioxide from the air, this can lead to a slightly acidic pH over time.

Production Process

The production process of deionized water primarily involves removing mineral ions. This is achieved through various methods, each ensuring the production of high-purity water.

Distillation

In distillation, water is boiled and the resultant steam is captured and condensed. This process takes advantage of the different boiling points of water and dissolved substances.

  • Boil water in a chamber.
  • Collect and condense steam into a separate flask.
  • Result is water with reduced ion content.

Ion Exchange

Ion exchange is a chemical process that uses resin beads to replace mineral ions like calcium and magnesium with hydrogen and hydroxide to form pure water.

  • Water passes through ion exchange resins.
  • Ions are replaced with hydrogen and hydroxide.
  • Outcome is deionized water.

Filtration

Filtration involves the physical removal of impurities through fine physical barriers or chemical processes.

  • Utilize filters to trap particles.
  • May include activated charcoal to remove organic compounds.
  • Final water is clearer and contains fewer ions.

Uses and Applications

Deionized water serves critical functions across various industries due to its high purity level. This high degree of purification makes it an essential component in environments where the presence of minerals could lead to interference or damage.

Laboratory Use

In laboratory settings, deionized water is indispensable. Scientists rely on its purity for precise experiments, as contaminants can drastically alter results. They also utilize it for cleaning instruments to prevent residue that could skew future tests.

Pharmaceutical Industry

Pharmaceutical companies employ deionized water to ensure product safety and efficacy. It is used in the production of medications, both over-the-counter and prescription, as an excipient, a substance formulated alongside the active ingredient of a medication.

Electronics Manufacturing

Within electronics manufacturing, deionized water is utilized for washing and rinsing electronic components. It helps in preventing the accumulation of minerals that could lead to short-circuits or corrosion, thereby safeguarding component reliability.

Handling and Storage

In laboratories, the purity of deionized water is paramount, thus careful handling and storage strategies are necessary to prevent contamination.

Pouring water from bottle into glass on white background

Containment

Deionized water should be stored in containers made of non-reactive materials such as glass or certain plastics like polyethylene to maintain its purity. It is imperative that these containers remain airtight to avoid absorption of CO₂ from the atmosphere.

Shelf Life

Although deionized water does not expire, its quality is best preserved when used shortly after production. Over time, it may absorb impurities or carbon dioxide from the surrounding environment, which can compromise its deionization status.

Safety Measures

Handling deionized water requires adherence to certain precautions. Handlers should wear appropriate protective equipment to prevent skin contact. The storage area should be clean, dry, and away from direct sunlight or heat sources to prevent degradation of water quality.

Quality Standards

Quality standards for deionized (DI) water are critical in ensuring its suitability for various applications, particularly in laboratory and industrial settings.

Fresh drop of water on glass, refreshing hydration

ISO Certifications

The International Organization for Standardization (ISO) sets forth parameters for water quality that include criteria like pH value, conductivity, absorbance, and silica content. ISO 3696:1987 classifies water into three grades according to its degree of purity, with Grade 1 representing the highest purity level suitable for the most stringent analytical requirements.

ASTM Specifications

ASTM International, formerly known as the American Society for Testing and Materials, has developed ASTM D1193-06(2018), a standard that defines specifications for reagent water. It categorizes the purity of laboratory-grade water into four types, with Type I water being the most pure, commonly used for critical laboratory applications. The table below summarizes the ASTM types and their corresponding purity levels:

ASTM Water Type

Description

Type I

Used for analytical procedures that require the lowest level of impurities.

Type II

Suitable for general laboratory applications, including qualitative analyses, microbiological testing, and preparation of solutions for chemical analysis.

Type III

Adequate for routine laboratory applications, such as washing and rinsing, where high-purity water is not essential.

Type IV

Primarily used for washing glassware, rinsing laboratory instruments, and preparing reagents for chemical analysis.

Environmental Impact

The production and treatment of deionized water have discrete environmental considerations, particularly in waste disposal methods and recycling opportunities.

Waste Disposal

The deionization process generates waste primarily consisting of concentrated mineral ions. Proper waste management is essential, as improper disposal of this waste can lead to environmental damage. Regulatory compliance ensures that the ions do not contaminate local water systems.

Recycling Methods

Innovations in recycling methods for deionized water systems are crucial for environmental sustainability. Recycling reduces the volume of waste and the frequency of resin replacement. Systems that reclaim or regenerate spent ion exchange resins are increasingly being adopted to minimize the ecological footprint of deionized water production.

closeup of water splashing glass

Frequently Asked Questions

In this section, readers will find concise answers to common inquiries about deionized water, its production, uses, and comparison to other types of purified water.

What is the difference between deionized and distilled water?

Deionized water has had its mineral ions removed, typically using ion exchange processes. Distilled water is created by boiling water and collecting the condensation, resulting in the removal of minerals and impurities.

What are the common uses of deionized water?

Deionized water is often used in laboratories, electronics manufacturing, and the automotive industry, especially where the absence of ions is crucial to prevent contamination and ensure high-quality standards.

How is deionized water produced?

Deionized water is produced by passing water through ion exchange resins that remove mineral salts and other charged ions from the water, resulting in purified water.

Can deionized water be used for consumption?

While deionized water is safe to drink on occasion, it is not recommended for regular consumption as it lacks beneficial minerals typically found in potable water and may acquire contaminants from storage containers.

How does the cost of deionized water compare to other forms of purified water?

The cost of deionized water can vary depending on the production scale and intended use but is often more expensive than simple filtration methods, yet may be less costly than distilled water production which requires significant energy input.

What are the components of a typical deionized water system?

A typical deionized water system includes ion exchange resins that remove cations and anions from the water, as well as pre-filters and post-filters to ensure the removal of non-ionic organic contaminants and to check water purity.

Want to Know More About Our Products

View All Products Now