Non-Chemical water treatment removes the headaches of chemical feed systems while providing a less complicated solution for your cooling tower’s makeup water quality. But there are a few qualifications. EAI Water finds that non-chemical options best suit facilities trying to achieve the following:

1. LEED Certification Points
2. Treatment in hard-to-reach spaces, where administering chemicals is challenging
3. Reusing blowdown water onsite (irrigation, restroom water). These applications would require you to minimize chemical additions to the water.
4. Compliance with strict municipal sewer limits that make chemical addition too costly

Facilities motivated to go chem-free need devices that limit bacteria growth and prevent scaling and corrosion like chemical feed systems. The following technologies accomplish this without biocides, anti-corrosion, and anti-scalants.

1. Electrodeionization (EDI)  – uses positive and negative electrodes in conjunction with ion exchange membranes, and resin to remove salts from your makeup water. This allows you to control scaling in your tower without chemicals. The electric field continuously regenerates the ion exchange resin, as opposed to ion exchange resins by themselves that require chemical additives to regenerate. Closely related, Capacitive Deionization (CDI) uses a similar process, often with carbon-based electrodes. Both are mainly used with feedwater, but have been tried over the years for recirculating water as well.
2. Electrochemical Deposition – If your system suffers from scaling, Electrochemical Deposition flows makeup water through a charged reactor rod before entering your cooling tower. The machine encourages minerals to scale to a reactor rod before entering your cooling tower.
3. Pulsed Power – uses an electric pulse both to precipitate hardness (scale) out of the water and to disrupt bacteria reproduction. The result is powdered minerals that don’t scale and limit bacteria growth.

You’ve met the technologies and learned how they work, but all changes come with challenges. Here are the most common drawbacks to chemical-free treatment methods:

1. Hard Water Sensitive – These technologies don’t perform well in notably hard water. Test your makeup water’s hardness when researching non-chemical treatment options.
2. Labor Intensive – Generally, non-chemical treatment demands more labor hours than chemical systems. For example, Electrochemical Deposition systems require cleaning to remove the scaling from its chambers. Before installation, alert your maintenance team of new SOPs and expectations.
3. Legionella Considerations – While chemical-free technologies treat minerals and bacteria to industry standards, EAI Water’s experts find oxidizing biocides are best for preventing legionella bacteria. If your facility is particularly vulnerable, i.e. hospitals, hybrid systems offer effective treatment while reducing chemical budgets. EAI’s recommended hybrid system is a Pulse Powered device with a solid form of oxidizing biocide.
4. Electric Dependent – Non-chemical treatment technologies need electricity to treat your makeup water. During a power outage, these technologies cease to work and your cooling tower makeup water quickly goes untreated. When considering a non-chemical option, review your current electrical backups and any additional electrical infrastructure required to avoid treatment failure.

Expectations

If your system meets the criteria above, non-chemical treatment could save you money and make cooling tower maintenance easier. As you move forward, remember:

1. High Turnover Systems Preferred – Non-Chemical treatment doesn’t treat large, stagnant pools of water effectively. These technologies operate best when recirculating water is consistently moving throughout your cooling tower. 
2. Higher Upfront Cost – Your initial investment will cost more than traditional chemical feed pump skids. Facilities save via lower chemical costs over time. Work with a vendor to find how these options would financially benefit your facility long term.

While it only fits some cooling towers, many facilities could simplify their makeup water treatment with non-chemical technologies. If decreasing your chemical consumption is a goal at your facility, see the exciting advancements EAI Water is making in water treatment.