In the fourth and final part of our series for the beverage industry, we cover on-site chemical generation. Here we take a look at proven on-site chemical generation technology for disinfection and its ability to improve water quality and safety while minimising maintenance and operational costs.
Recently, we hosted the fourth and final instalment in our four-part series of webinars on sustainable disinfection solutions for the beverage industry. It has been great to see the interaction and discussion generated across the series. Now, let’s take a look at applications for on-site chemical generation within beverage processing plants. We’ll cover the benefits, considerations and effectiveness.
As a global leader in the development and supply of water technology solutions, Evoqua offers a number of innovative treatment systems including UV disinfection, ozone and today’s topics, electrochlorination and chlorine dioxide generation.
Chlorination has been a fundamental and successful disinfection method within municipal water supplies for over 100 years. It relies on the reaction between water and hypochlorous acid (HOCl) and hypochlorite ion (OCl –). The acid reacts with any oxidizable material, killing microorganisms by destroying cell enzymes and cell membranes. It is highly effective at killing e. coli, listeria, salmonella and aids in the prevention of biofilming[1].
It is extremely effective, but it is crucial to consider concentration, contact time and your target organisms. Also consider the composition of the water, with nitrogen, ammonia and the presence of in-organics affecting the reaction. On-site generation systems for chlorination are enhanced and optimised with proper analysis and control – measuring and ensuring the stability of conductivity, turbidity, pH, temperature and residual is essential.
Here at Evoqua, we implement effective on-site generation chlorination systems for clean-in-place (CIP), surfaces and cooling water. Clean-in-place, particularly, is very popular in the beverage industry where processes reach 150˚C and residual chlorine can be ‘heated off’ – perfect for soft drink and fruit juice applications.
At Evoqua, we believe that on-site generation is the safest and best way to implement chlorination disinfection, eliminating hazardous handling. It is also far more efficient and sustainable, with the ability to meet real-time demand. With effective and proven disinfection automated to fulfil requirements, beverage operators can focus on production rather than water treatment.
When it comes to on-site systems, we provide our highly regarded OSEC® system, which generates hypochlorite on demand, as well as our on-site Chlorine Dioxide Generators. Both technologies simplify and enhance chlorination, with OSEC systems successfully applied to industrial and municipal applications for more than 30 years.
The OSEC system is also a sustainable solution, with the ability to innovate by leveraging ‘reclaimed’ water, improved accessibility to raw materials and operational independence. With easy access components, simplified connections and no need for tools, it is a robust, efficient and reliable system that has been proven by customers around the world.
Our Chlorine Dioxide Generators use low concentration chemicals with safety interlocks and on-demand generation. These systems have had an industry presence for more than 60 years and are 2.75 times more effective than conventional solutions, allowing for relatively low dosages. We offer pre-wired, pre-piped and compact systems with easy access to all components and communication with Plant SCDA/BMS.
To paint a wider picture of the benefits of on-site chemical disinfection, we’ve answered some of your frequently asked questions.
A. Legionella are contained in freshwater almost everywhere and can spread quickly in a plant, with a doubling time of just 3 hours at 45˚C. They do not survive temperatures above 55˚C, however, usually permanently heating the water is not an option[2]. A sustainable disinfection approach is essential, and the only reliable way is chemical disinfection, which can remove and prevent biofilm. Removing particulates is also important.
A. On one hand, sustainability may be related to equipment durability and process stability, but also to the carbon and water footprint. In this regard, we should mention that Evoqua provides proven and highly durable equipment, and our disinfection technologies enable water reuse. For example, CIP water reuse due to the deposit effect of the supplied chemical. Additionally, the OSEC® system avoids the requirement to transport large quantities of water (contained in commercial sodium hypochlorite) by road, alongside considerations for the decay of commercial ‘bought in’ hypochlorite.
A. One of the most interesting advantages of the OSEC system is that you just need the salt, water and energy you have on your plant, so you just need to purchase and store salt. This reduces a plant’s reliance on the supply chain.
A. When you add chlorine dioxide, you need to be aware of two things. One is the excess of acid in the chlorine dioxide solution, the other is that chlorine dioxide oxidizes iron – Fe2+ and Fe3+, precipitating to iron hydroxide. These precipitates can be an area for bacterial growth and can also disturb other processes. A settling tank could be needed for their removal.
A. Its effectiveness is mainly seen in combatting the biofilm[3]. If it is a new plant, the biofilm will be prevented. For an existing plant, the biofilm will start breaking. The solution is to start with a small dose to prevent downstream blockages.
To find out more you can watch the webinar here. If you have any questions about Evoqua’s chemical disinfection solutions and how they can enable your sustainability ambitions, please get in touch with Sueli Roel at sueli.roel@evoqua.com
Evoqua OSEC® systems are designed to produce 0.65-1% sodium hypochlorite under normal operating conditions. With less than one minute of contact time, the OSEC®-produced concentration range (6,500-10,000ppm) is significantly higher than the concentration requirements to meet industry standards for microorganism inactivation and disinfection. Specific disinfection rates depends on dose, concentration and time (CT value), pH, and water temperature. Performance limitations depend on feed conditions, overall installed system design, and operation and maintenance processes; please refer to Operations Manuals. For more information: Contactus@evoqua.com
Evoqua’s Chlorine Dioxide Generation systems make no claim regarding disinfection. These systems apply EPA-registered chlorine dioxide precursor chemicals, for which the generation of chlorine dioxide used as a disinfectant for microbial control in water is presented on the labels’ directions for use. Performance limitations depend on feed conditions, overall installed system design, and operation and maintenance processes; please refer to Operations Manuals. For more information: Contactus@evoqua.com
[1] Bang J., Hong A., Kim H., Beuchat L. R., Rhee M. S., Kim Y., et al. (2014). Inactivation of Escherichia coli O157: H7 in biofilm on food-contact surfaces by sequential treatments of aqueous chlorine dioxide and drying. 191 129–134. 10.1016/j.ijfoodmicro.2014.09.014
[2] Loret JF, Robert S, Thomas V, Cooper AJ, McCoy WF, Lévi Y. Comparison of disinfectants for biofilm, protozoa and Legionella control. J Water Health. 2005 Dec;3(4):423-33. doi: 10.2166/wh.2005.047. PMID: 16459847
[3] Stage 1 Disinfectants and Disinfection Byproducts Rule (Stage 1 DBPR) 63 FR 69390, December 16, 1998, Vol. 63, No. 241 Stage 2 Disinfectants and Disinfection Byproducts Rule (Stage 2 DBPR) 71 FR 388, January 4, 2006, Vol. 71
