Getting the best results from your laboratory water purification system

Triple Red’s Dr Matthew Mayhew shares some advice concerning laboratory water purification systems that will help you to run your equipment more cost-effectively and with less waste

In scientific applications, the pure water used in laboratories must pass through various technologies to remove impurities.

Depending on the application requirements, the type of water purification system will vary, so a range of laboratory equipment is available. Whatever the specific system, good working practices are essential to ensure that the equipment runs efficiently and at peak performance.

With waste-reduction a significant issue, we’ve identified some key measures you can take to ensure your laboratory water purification systems run efficiently with minimum waste.

Rinsing water purification cartridges: Water purification cartridges should be rinsed thoroughly before initial use to remove any preservatives added during manufacturing.

This is particularly true for reverse-osmosis (RO) cartridges. The rinsing reduces total organic carbons (TOC) and increases resistivity, prolonging the life of the cartridge and making it more cost-effective. When looking for cartridges, it’s worth identifying those that only require changing based on the amount of water that has been used.

Storage of purified water: Pure water absorbs impurities with time and water storage tanks may leach organic or ionic compounds.

Recyclable high density polyethylene (HDPE) should be used to store type 2 water prior to polishing. If the storage tank has a smooth and crevice-free interior then it’ll have 100% draining capacity; a conical base allows total removal of contents when cleaning. This makes sanitisation simple, meaning that less waste water is flushed down the drain.

Monitoring water quality: The water quality used in the sample and solution preparation stage is as important as other reagents.

Monitoring water quality — both resistivity and TOC — continuously is essential to ensure that results are accurate and repeatable and all impurities are accounted for.

Further energy efficiency benefits are gained by some innovative water purification systems, which are able to measure the conductivity during the final purification stages. Any water that does not meet the required standard can be recycled back around the system rather than flushed down the drain.

Sample containers: Ultrapure water is an excellent solvent and will try to bind with whatever it comes into contact with. This includes its storage container, so these should be made from inert material.

Flushing the system: With time, bacteria will grow and air will penetrate a laboratory water purification system. Keep this to a minimum by changing the hydrophobic air filter regularly and sanitising the system annually.

Energy saving features: A number of water purification systems available today offer all-important energy saving features, which not only benefit the environment, but also make your processes more efficient.

Some systems run on variable speed motors, which have an energy saving “sleep” mode when not in use. Additionally, variable speed motors mean that they only use the amount of energy required.

Even when in full use, the energy consumption of the best laboratory water purification systems is the equivalent of running a domestic lightbulb. Not only does this make your laboratory a quieter working environment, it cuts running costs, preserves natural resources and reduces pollution.