A Dairy in California had a large process chilled loop that frequently became contaminated with milk products. The milk products provided an excellent source of food for a variety of bacteria. Since the chilled loop is considered a potential source of food contact, the bacteria in the chilled water had to be maintained below detectable limits to comply with regulatory requirements. For twenty years, the Dairy had used traditional biocides to battle the problem. However, they either failed to prevent biological fouling, caused corrosion and often resulted in excessive treatment costs. Detectable levels of bacteria required immediate emergency maintenance that caused a significant increase in operating costs and, at times, unscheduled downtime. Yet, failure to take immediate action could result in even greater product loss, a potential shutdown mandated by state or federal regulators, or the potential outbreak of a bacteria-related illness among consumers that could trigger huge revenue losses.

For twenty years, the Dairy tried a variety of non-oxidizing and oxidizing biocides in an effort to remedy the problem. These were industry-standard biocides commonly available to water treatment service providers. The non-oxidizers proved to be ineffective in terms of cost and efficacy. These products did not penetrate the slime layers that formed in conditions found in the chilled water loop. As a result, there was a rapid recovery of the bacteria levels in the circulated water. Frequent high-dose shock
treatments were required to maintain system hygiene, but these treatments were costly and created a significant increase in organic loading. The oxidizing biocides used were all classified as “surface burning agents.” Organic loading in the chilled water created a heavy demand on these products. Feeding the oxidizing biocides at dosages required to meet this demand and achieve a successful kill created significant corrosion throughout the system.

The client purchased and installed a PureLine Model P-6E chlorine dioxide gas generator. PureLine’s electrochemical chlorine dioxide generation systems produce a pure gas stream using just one precursor. Purecide 25 sodium chlorite is used in a patented electrochemical system where it is converted into a chlorine dioxide solution. The chlorine dioxide is stripped from the solution using an eductor and proprietary stripping column. The resulting pure chlorine dioxide gas is immediately introduced into the water or air stream to be treated. The generators are equipped with a state-of-the-art control package that makes operating the system easy and facilitates an immediate automatic response to the demand for disinfectant.

PureLine’s safe and reliable method for generating chlorine dioxide provided the Dairy with an alternative to the biocides it had been using. Safe, pure, effective chlorine dioxide did not add to the organic loading or produce significant corrosive salts, introduce outside fluids, or affect system pH. Pure chlorine dioxide proved to be a highly efficient kill agent even at low dosages and was completely compatible with the existing treatment program formulations. The chlorine dioxide was able to penetrate and eliminate the slime formations without attacking system metallurgy. Because PureLine’s proprietary on-line control system automatically monitors the system for any contamination, it was easier to maintain the system’s cleanliness and prevent unexpected emergency maintenance or shutdowns.

PureLine’s innovative chlorine dioxide generation technology and control instrumentation, combined with the company’s professional service program, provided a successful treatment solution that was easy for plant operators to implement––even with the demanding schedule constraints typically found at most of today’s dairy production facilities. Safe and reliable technology supported by exceptional professional technical service virtually eliminated plant maintenance requirements. Intensive daily
monitoring was reduced to routine checks that required less than 10 minutes per day.
For less than $2,500 per month, the Dairy now receives a comprehensive packaged solution that includes a full-service agreement, as well as an additional open-cooling system disinfection program that is safe for continuous critical food contact. Overall, PureLine’s program fees are very competitive with other traditional treatments the Dairy had used in the past. Better efficacy and system protection, a reduction in unscheduled maintenance, and easy implementation have all made PureLine’s chlorine dioxide generator a much more cost-effective solution to the Dairy’s problems.

PureLine’s safe, reliable and highly effective chlorine dioxide gas generators serve as an alternative to biocide in applications where potable acceptance may affect the efficacy and application of traditional biocides, as well as applications where there are:
» persistent pathogens.
» heavy organic or other contaminant loading.
» system conditions that reduce contact time.
» extended system retention time with oxidant-sensitive treatment
formulations and system metallurgy and where potable acceptance
may affect the efficacy and application of traditional biocides.

As a result, PureLine’s chlorine dioxide generators offer ideal disinfection solutions for drinking water, chilled water, process waters, industrial and municipal wastewater, reclaimed water, air emissions
control, re-used and water conservation applications.