Water Impurities and Laboratory Water Purification Systems

Water sources have a variety of qualities, characteristics, and purities depending on the land they originate from, the geographical formations, and environmental conditions. Underground water is a stable source of water that is high in minerals. However, it can be contaminated by agricultural runoff, industrial processes, landfill or septic system pollution. River water often contains high levels of pollutants from urban, agricultural, and industrial runoff which can lead to microbial contamination, with bacteria, viruses and protozoans. Upland area water is typically less polluted than lowland water, but regular monitoring of its quality is essential, as pathogens such as Giardia and Cryptosporidium can be caused by contamination from wildlife.

The purity of water can also differ depending on the season and region. Warmer temperatures can increase algae and bacterial growth, and dry weather can lower water levels, which concentrates existing contaminants. Rainy seasons can increase the level of runoff from land surfaces into rivers, and the spring snowmelt can encourage contaminants as a result of accumulated winter pollutants. The water source’s region can also impact contaminant level with agricultural and urban areas prone to increased runoff and subsequent pollution.

When producing laboratory-grade water, it is vital to consider the quality of water and its characteristics. This article will look at the impurities and variations found in drinking water, and methods to create lab-pure water. We will also discuss the role that water purification systems play in purifying drinking water, and the generation of feed water for the lab purification systems.

Water is one of the few substances capable of dissolving virtually every chemical compound to some extent and supporting practically every form of life. This means that drinking water supplies contain many substances that may be suspended or dissolved in the water. A wide variety of contaminants can affect the performance of scientific and laboratory applications by interacting with other substances.

Various impurities can be found in natural and drinking water, which can be divided into five categories:

• Biomolecules and microorganisms like bacteria, viruses, and parasites, as well as proteins and DNA present in water.
• The clarity of water can be affected by suspended particles such as sand, silt, and debris.
• Water-soluble inorganic compounds include heavy metals (e.g., lead, arsenic), salts, and minerals.
• Organic compounds that dissolve in water, such as pesticides, herbicides, and industrial chemicals.
• There are many gases that can dissolve in water, such as oxygen, nitrogen, and carbon dioxide.

Bacteria – major water contaminants
Bacteria are the primary microorganisms contaminating natural water sources. Chlorination removes harmful bacteria, but traces of live microorganisms often remain in drinking water. Bacteria can multiply once chlorine or other disinfectants are removed during water purification. Residual chlorine or other disinfectants help to keep bacteria levels low.

The presence of bacteria in water can interfere with laboratory experiments directly or indirectly via pyrogens, alkaline phosphatases, and nucleases. Water sanitisation is therefore essential to ensuring the integrity of laboratory work.

Role of Laboratory Water Purification Systems
In laboratory applications, water impurities can significantly affect experiments and analyses in various ways:

1. Contamination of samples
Laboratory samples can be contaminated with bacteria, viruses, and chemicals, resulting in inaccurate results. Microbial contamination can affect cell cultures or molecular biology experiments, while chemical impurities can interfere with chemical reactions.

2. Interference with the reagents:
Impurities in water can alter the effectiveness of reagents used in laboratory tests. The reliability and reproducibility of experiments can be affected by false-positive or false-negative results.

3. Effect on instrumentation:
Lab equipment and instrumentation can be damaged by impurities in water. In analytical instruments, mineral deposits or particulate matter can clog filters, affect flow rates, or cause corrosion.

4. Quality of results:
Water impurities can compromise experimental data quality. Precision in the measurement is crucial in fields such as clinical diagnostics, where water quality parameters are studied.

5. Health and safety concerns:
Impurities in water, such as toxic metals or pathogens, can pose health risks to laboratory personnel. To mitigate these risks, safety measures and water quality testing are required.

Water Purification Methods
The water purification process begins with a pre-treatment stage designed to minimise damage to subsequent purification components. This is done to ensure reliable operation and reduce operational costs by extending lab equipment lifespan. Various water purification methods including Reverse Osmosis, Ion Exchange, Electrodeionisation (EDI), Distillation, and Ultraviolet (UV) light can then be employed to effectively remove impurities from the water.

The choice of the most suitable lab water purification method depends on the specific characteristics of the incoming feed water, such as its composition and contaminants levels, in conjunction with the user water quality specification. Selecting the appropriate purification approach ensures optimal water quality for various applications in your laboratory.

Role of Laboratory Water Purification Systems and Purite expertise
Laboratory water purification systems enable the production of high-purity water for use in a range of applications. For more understanding of the importance of using lab pure water why not read The Importance of Pure Water in Labs?

Depending on the requirement, lab feed water can be processed into Type 1 (ultrapure), Type 2 (pure), or Type 3 (general laboratory-grade) lab-grade water. To create these grades of water, lab water solutions remove particulates and suspended solids using filtration systems. Dissolved inorganic ions are removed using deionization (DI) and reverse osmosis RO water purification systems. Activated carbon filters and UV oxidation (185nm) can also be used to remove organic impurities, and UV sterilisers (254nm), ultrafiltration and biocidal agents to eliminate microbial contaminants. To understand more about lab water purification systems read Understanding Lab Water Purification Systems.

With over 40 years of experience in water purification for labs and other applications, Purite designs, manufactures, and supports the creation of custom-engineered and standard solutions that are used by scientists, researchers, healthcare, industrial and process specialists around the world.

Contact us today to learn how we can help you generate high-purity water for all your application needs.