Environmental considerations for cooling water inhibitors

Chemical treatment of cooling systems is a generally accepted need to minimise water chemistry related problems.  There has always been a balance between safe handling, application of chemicals, performance, reliability and cost. There are a wide range of scale and corrosion inhibitors used in water systems depending on the conditions and chemistry of the recirculating water. Typically these chemistries include heavy metals (Zinc) and phosphorus based programs. The consequence of cooling system ‘blowdown’ is that residuals of these active ingredients become a less desirable addition to wastewater leaving a facility. In certain regions of the UK, there are increasing restrictions on the discharge of phosphorous so any measures to reduce the upstream addition to water supplies is  beneficial.

Recent innovations in inhibitor chemistries have introduced high performance with non-metallic compounds and products which do not contain phosphorus or perform with lower phosphorus based compounds. The utilisation of alternative applications methods (using solid based chemistry versus liquid chemistry) affords improvements to packaging, transport and manual handling costs.

Finally, alongside a balanced review of mechanical, chemical and operational challenges of a cooling system - inhibitors can be utilised to drive higher performance (through increase of concentration cycling).

Considerations for your cooling system

  • Do you need a low or non phosphorous program? 
    • If the blowdown does goes directly to the environment then you may consider a low or non phosphorous program
  • Does your blowdown go to a biological treatment plant? 
    • If the blowdown goes to a biological treatment plant then phosphorous will be needed for biological treatment
    • If your blowdown goes to a biological treatment plant then you will need to ensure that the chemicals in the cooling system will be degraded by the biological treatment plant and not harm the bacteria
  • Does your blowdown go to a recycle treatment?
    • Make sure chemicals in the blowdown are compatible with the process where the water is being recycled to.
  • Does your blowdown go directly to the environment?
    • Look for low P or non P programs and products that are readily or inherently biodegradable
  • Are there opportunities to improve on local social responsibilities?
    • Look into what the corporate or local green initiatives are and what chemicals might help?

Our Hydrex range of cooling water inhibitors that offer ‘green’ alternatives include:

Hydrex 2281: a zinc-free solid chemical used as an organic scale and corrosion inhibitor for cooling towers fed with medium to hard water. The use of solid chemicals means that there are no heavy drums to handle which reduces the risk of injury from manual handling and also from hazardous spills and splashes.  Solid chemicals also have a better environmental profile in relation to transportation and warehousing, this also means that less storage space on site is necessary.

Hydrex 2438: a non-zinc based cooling system corrosion and scale inhibitor. It includes an inorganic film forming corrosion inhibitor and specific agents to avoid scaling and deposits of suspended solids.  It exhibits excellent corrosion inhibition on softened and low hardness waters.

Hydrex 2111: a non-phosphorous based antiscalant and corrosion inhibitor.

Hydrex 2340: an organic antiscalant and corrosion inhibitor.  It contains no metallic salt or phosphorous.

Hydrex 9209:  a zinc-free and phosphorus-free scale inhibitor and dispersant. It has exceptional stability in harsh water conditions. It is the best in class at crystal habit modification for calcite scale and can be used to replace or reduce phosphonates and P contribution.  It is highly effective at low dosages.  

If you would like to understand the alternatives to your existing program, your first step is to arrange a free consultation with one of our experts, and you can book this below.



Jim Knight

About the Author

Jim Knight

Jim has over 25 years experience in the water treatment and cooling tower industry. The first 17 years were spent working for Nalco and Akzo Nobel in senior roles, working in account management and sales roles. His customer focused approach and chemical background made going into Veolia Water Technologies as a Business Development Manager a good fit. He has spent the last 8 years working in sales in the evaporative cooling industry having gained wealth of knowledge from the role, proving to be a valuable asset.