Mastering the art of water treatment

Have you ever been to a circus and been impressed by the performers above you boldly walking the tightrope? This display of grace and balance may leave many in awe but for those working in water treatment it’s actually just a physical manifestation of their job! Come one, come all, as Dr Simona Vasilescu, of the Water Treatment Platform NCH, explores the greatest show in chemistry.

Effective water treatment is a balancing act of accuracy, awareness and knowledge. While many that are not directly involved in the processes may view it as a simple case of dropping some solution into a water cooling system and walking away, the actual process is entirely reliant on precision and in depth knowledge of the water in the system. Inaccurate dosing breeds ineffective treatment, and ineffective treatment can breed much larger problems, like Legionella.

Identifying specific problems is the first step to mastering the tightrope of water treatment to avoid falling into the lion’s den of Legionella. For example, the problem in your system may not be Legionella at all – it could be calcium present in the water supply. In this instance a solution would need to be able to combat scaling, so a corrosion inhibitor would be of no use.

Likewise if an engineer only doses one part per million (ppm) of solution when, in actuality, their system requires at least three, the whole thing becomes an exercise in futility. But, while it is crucial that an engineer ascertains the precise amounts needed, there are a range of other factors that must be taken into consideration in order to provide effective treatment.


The half-life of a solution, for example, can render an effective treatment strategy unsuccessful. Over time, a solution’s concentration will decrease as water either evaporates or is released as runoff, which is why consideration must be given to the specific needs of the system. Otherwise, you could be dosing all the right solutions but not to high enough levels to remain at optimum concentrations long enough for the biocides to do their job.

In some instances, biocide solutions can take a number of hours to become fully effective in a system. If a system’s bleed flow means that the half-life of 300ppm of the biocide is two hours, it won’t start working until it’s already at less than 50 percent effectiveness.

To keep on top of this, engineers can calculate the product half-life by completing an equation using the bleed rate of the water supply and dose accordingly. Instead of using 10ppm of an inhibitor to condition 300ppm of calcium and combat scaling, engineers should use more depending on their specific calculations.


Of course, the world is not so perfect that water treatment providers can always identify problems with pinpoint precision. It is not uncommon for fluctuations to occur, which can lead to an increase in contaminant content and cause problems for treatment solutions.

For example, a plaguing 300ppm of calcium may be easily treated with 10ppm of scale inhibitor, but a sudden influx of 5ppm of calcium in the source water results in the active dose being overwhelmed by contaminant. There are a range of reasons that this may happen, such as a bleed valve shutting on the system.

In instances such as this, one may naturally assume that the best course of action would be to just add more solution. However, in dosing further, it becomes increasingly difficult to avoid crossing the line of over-treating the water supply.

To quell this fluctuating problem, NCH has developed crystal modifiers that can work alongside threshold inhibitors to provide extra support. If calcium fluctuations do occur, the modifiers get to work in doing what the name suggests and modifying the molecular structure of the calcium itself. This modification smoothes out the edges of the calcium molecule and renders it unable of clinging to metal pipes, dropping the curtain on the risk of scale building up.

A flawless routine

Once immediate issues have been addressed, it’s a matter of sticking to an ongoing routine of treatment that will keep the contaminants under control. A good treatment strategy will not rely solely on treating water with the same solution every month, but will regularly assess the water and adapt accordingly.

No two assessments are ever the same, so it is vital that water treatment providers are able to offer ongoing support and expertise to company engineers. We pride ourselves on our technical knowhow at NCH, and we make sure that each of our clients receives the best bespoke treatment solutions that remain effective.

In a sense, water treatment’s impressive balancing act is not just a case of maintaining equilibrium while on the tightrope but managing the overall performance of the event. By paying due consideration to all of the details, businesses can take on the role of ringmaster to maintain order and prevent costly downtime. After all, the show must go on!