IOA column

Ozone Sanitization of Purified Water Loops

irtually every company that makes products where one of the System Considerations Compatibility of in-line equip- V ingredients is water has installed elaborate water treatment ment must be confirmed versus the expected doses of ozone. As ozone systems to purify the water provided from their local municipality. decays rapidly in the presence of heat, ambient water temperatures above One “impurity” that is removed is the residual chlorine. Once 80°F are problematic. The overall ozone loop length must be determined removed, the water no longer has residual disinfection powers. This due to the inevitable decay of ozonated water pumped from point to point. high-purity water is often stored and recirculated in process loops that Lines greater than 350 ft may require additional ozone at the inlet. provide the water to a variety of points of use. Proper integration of the ozone system into the company’s existing By Chris Rombach Keeping tank and piping systems maintaining low levels of ozone in the process is essential. Coordination free of biofilms and other microbial water in the storage tank and subse- between the production, engineering contamination can become a chal- quently having the capability to elevate and quality departments must meet lenge. The key is regular sanitization levels to disinfect the entire purified the needs of individual stakeholders. of the water distribution to maintain water loop. An integrated system can Through careful planning, ozone acceptable microbial limits. be installed to provide ozone-enriched can increase line utilization, improve water to the storage tank via a small overall product quality by minimizing Benefits and Sanitization Requirements side stream recirculation loop. Ozone or eliminating contaminations in the While other process/product lines monitors are placed at the outlet of factory water supply and help manu- considerations when may be connected to a multi-step clean- the storage tank, post-UV and then facturers meet regulatory and product in-place system, purified water loops at the end of the return loop. During safety requirements. sanitizing purified typically are not. Companies perform sanitization, the ozone dose and the While many companies have UV the sanitizations internally or hire residual at the return of the loop are systems already installed inline, the water loops water treatment companies to sanitize critical measurement points. Before company must confirm that the unit the equipment in the loop. Typically, production resumes, the UV light is operating at 254 nm, the most effec- chlorine-based oxidants or acids are must be restarted and once the ozone tive UV wavelength for ozone destruc- utilized. This can be time consuming, monitor shows the complete lack of tion. The sizing of the UV must be expensive and does not always provide ozone in the water, manufacturing can confirmed by the manufacturer to the desired results, leading to more begin again. assure the destruction of ozone can be frequent sanitizing and higher concen- Ozone-based sanitization can be accomplished at the designed flow rate. trations used. If unsuccessful, product carried out weekly, monthly or quar- contaminations are likely. If persis- terly. Systems can be manual or fully Realizing Benefits tent biofilms are allowed to flourish, automated and integrated into the Ozone is increasingly being used removal can become nearly impossible. plant’s water process system. Such to sanitize purified water loops at Ultraviolet (UV) disinfection systems systems can be programmed to run production facilities. Reductions in are often installed, which cannot during non-production time and can chemical expenditures, water usage, protect against bacterial ingress that be quickly brought back on line with lost production time and sanitization may occur downstream. little interruption to weekly outputs. time can be realized with the adoption of ozone for purified water loop Portable or Integrated Ozone Advantages sanitization. Implemented correctly, Ozone’s efficacy versus yeasts, • FDA-listed as organic and acceptable ozone can be a natural alternative to molds, bacteria, viruses and biofilms is for direct food contact; harsh chemicals. wqp well documented. It is easily generated • No disinfection byproducts; on site, highly effective and leaves no • No required flushing of the system; Chris Rombach is president of Pacific disinfection byproducts. • No chemicals are added to the Ozone Technology. Rombach can be Several approaches can be utilized. facility’s waste stream; reached at [email protected] or at Portable ozone systems are brought to • No chemical transportation/storage; 707.747.9600. facilities, connected to the water loop • Quicker: typical sanitization cycles and ozonate the water recirculating are reduced by 30% to 75%; For more information on this subject through the system. • Ozone can be turned off instanta- write in 1007 on the reader service card Integrated ozone systems can be neously by UV at 254 nm; and or visit www.wqpmag.com/lm.cfm/ installed permanently as a method of • Heat is not required. wq091007.

18 WATER QUALITY PRODUCTS