7 Compelling Reasons to Choose Ozone for Municipal Water and Wastewater Treatment
Across North America, many municipalities and communities are planning for necessary upgrades to their existing water and wastewater treatment infrastructure. Evidence of this need was clearly apparent last month when the U.S. Senate voted 89-2 in favour of the Drinking Water and Wastewater Infrastructure Act of 2021. This legislation will help communities address pressing water infrastructure challenges by providing significant boosts in funding for wastewater, stormwater, and drinking water. Similar increased funding is included in Canada’s recent federal budget.
Primary reasons for these infrastructure improvements are to address some or all of the following needs: 1) increased domestic and industrial water capacity, 2) a more robust solution to treat contaminants of emerging concern, 3) energy and greenhouse gas reduction, 4) reduction of wastewater dumping fees, 5) elimination/reduction of chlorine to protect people and the environment and, 5) to meet more stringent water disinfection regulations. Aclarus has extensive experience working with municipalities to address all of these issues with cost-effective, environmentally friendly ozone solutions that meet or exceed all required regulations.
Aclarus ozone technology has been specifically engineered to meet the needs of small to mid-sized municipalities with populations of 100,000 or less. We have considerable experience working with municipalities that have converted from chlorine to ozone. We also help municipalities supplement traditional UV treatment systems with ozone to enhance disinfection and water quality.
More and more municipalities, currently using traditional chlorine and UV systems, are now seeking environmentally friendly ozone solutions that deliver the superior disinfection necessary to treat complex water issues. Whether planning a new or upgraded system, careful consideration must be given to the long-lasting implications on the health and safety of the community and the environment. Supplementing or replacing an existing system with ozone will improve water quality, lessen environmental impacts and offers the potential to reduce costs. Here are 7 compelling reasons to choose ozone:
Ozone Requires Less Operational Expense = Quick Return on Investment (ROI)
There is a common misperception that ozone is expensive versus traditional treatments such as chlorine. The average operational cost of an Aclarus ozone system is approximately 5 cents per 1000L (1m3)of treated water. Ozone is produced on site therefore eliminating the need to purchase, transport, store and handle dangerous and toxic chlorine gas. Operator maintenance is minimal which also provides significant cost savings.
Ozone’s Small Footprint Allows for Easy Retrofit within Existing Infrastructure
Ozone systems are modular, easy to install, and require minimal space therefore they can often be retrofitted within the existing infrastructure to save costs and time. This is important for areas and communities with limited capital budgets. Unlike ozone, chlorine requires large water cisterns and contact chambers to provide the contact time necessary to penetrate contaminants and disinfect them. These cisterns require considerable space and cost to install. Because ozone delivers “instant-kill” disinfection with minimal contact time, it does not require extensive infrastructure and can use the existing chemical cisterns and chambers on-site for retro-fits.
An additional environmental issue to consider is ozone’s lower carbon footprint. The production and transport of chlorine incur GHG costs. Traditional water treatment facilities (ie chlorine and UV) require significant use of concrete for water beds and open channels. Concrete is reported to be responsible for 4-8% of the world’s C02. Every tonne of concrete produced, releases one tonne of C02, the primary greenhouse warming gas. With respect to building materials, only coal, oil and gas contribute more greenhouse gases. Concrete production is also attributed to up to a 10th of the world’s industrial water usage.
Ozone is a Superior Disinfectant...Faster and More Powerful than Chlorine or UV
Ozone is a chemical free disinfectant that literally splits organism cells instantly, resulting in an immediate kill of virtually all bacteria, virus and cysts. It is recognized as the fastest and strongest method of disinfection in both the US and Canada.
Chlorine requires much more contact time to treat pathogens, and is ineffective against cysts like Cryptosporidium because it cannot penetrate the shells, regardless of how much time the organism is exposed to it. Chlorine is also ineffective for the treatment of contaminants of emerging concern (CECs).
UV requires significant pre treatment of influent to provide UV transparent water, and the radiation’s short pathlength means presence of any chemical complexity like organic compounds can materially reduce effectiveness. A similar problem results if lamp sleeves are not cleaned continuously.
Ozone is simply more powerful against the broadest range of contaminants, and works nearly instantly. Furthermore, Aclarus’ advanced ozone technology can be engineered to treat many contaminants of emerging concern (CECs) effectively, such as pharmaceuticals, microplastics, and petrochemicals.
Ozone is Safer than Chlorine
Ozone is generated on-site, as needed. Once produced it breaks down rapidly to oxygen should any ozone be released within the treatment facility. Aclarus Ozone sensors immediately activate an alarm and shut off the ozone generator. Released ozone will quickly dissipate and the alarm will stop when it is safe to re-enter the building. By comparison a chlorine gas leak or spill is highly toxic, must be handled with extreme caution and requires considerable downtime for remediation and safe re-entry into the building. Operations using chlorine require training programs, certifications and emergency practices that must be routinely practiced. For these reasons, ozone is a much safer option than chlorine.
Ozone is a Chemical-Free Disinfectant that Protects Aquatic Life
Ozone is an environmentally friendly disinfectant that breaks down simply to oxygen. The dissolved oxygen that remains in the effluent water significantly benefits fish and other aquatic life as does ozone’s ability to remove colour and odour.
Chlorine, is toxic enough even in tap water, to burn the gills of fish and cause severe respiratory issues. Chlorine is absorbed through the bloodstream, kills cells and can cause internal burns in fish and other marine life. If concentration levels are high enough, chlorine exposure can lead to fatality. Chlorine and dechlorination chemicals that are used in municipal waste water treatment plants typically end up as carcinogens in water ways. These chemicals also reduce the oxygen level of water. For this reason, many environmental groups and concerned taxpayers are actively protesting the use of chlorine in their municipal water treatment facilities in order to protect the aquatic life in their communities.
Ozone Can Enhance Existing UV Wastewater Treatment
Ozone can supplement existing UV wastewater treatment systems to enhance their performance. Given that UV requires transparent water to operate properly, ozone is often added as a pre-treatment to effectively clean the water, making the UV system more effective and offering additional disinfection measures. Ozone pre-treatment has the added benefit of treating contaminants of emerging concern (CECs) which UV does not do effectively.
Ozone Lifetime Operational Cost is Lower than Chlorine & UV
Aclarus Ozone systems are sustainable, highly automated and require very little daily monitoring. Furthermore, all Aclarus ozone contact surfaces are made of non-corrosive stainless steel which eliminates the need for annual maintenance.
Chlorine treatment requires the purchasing, transportation and storage of chlorine gas and often sulfur dioxide as well to dechlorinate. Daily monitoring of these chemicals to comply with regulatory requirements can be labour intensive. In addition, chlorine contact surfaces must be replaced or repaired annually.
A UV water treatment system requires the regular replacement and disposal of mercury-based UV lamps and cleaning of the quartz sleeves that house the lamps. Although many UV systems have automated sleeve cleaning, this option is expensive, maintenance intensive, and often ineffective. Manual cleaning requires considerable and continuous operator maintenance.
In summary, there are many significant environmental, health, safety and cost-saving advantages to choose ozone for municipal water and wastewater treatment. The Town of Cobourg Case Study illustrates the many benefits of replacing a traditional chlorine wastewater treatment system with Aclarus Ozone.