Since the early 1990s, the use of ozone in many commercial and industrial laundering applications has been evolving rapidly. Ozone allows washing to be conducted using cold water, thereby saving considerable heat energy and water consumption. Additionally, ozone enhances the wash process, resulting in a significant reduction in detergent dosage and number of rinses, thus saving water. Ozone/cold water cycles are gentler to fabrics, thus extending linen life. Finally, ozone/cold water laundering is beneficial for effluents, resulting in reductions in COD (chemical oxygen demand). Microorganisms are destroyed effectively in ozone-wash waters, and washing and drying cycles are shorter, thus saving labor. In this paper, the authors describe some specific case studies at commercial laundering installations in the UK, whereby the users of ozone have reaped major benefits, including enhanced microorganism kills/inactivation and significant cost savings.
Introduction (ClearWater Tech, 2003, 2006)
Over the years, commercial laundry operations have improved by achieving higher per-load capacities and automated cycle and chemical management to ensure consistent quality over many loads. These improvements are notable, yet many financial and regulatory pressures continue to face commercial laundering, including
- Water consumption and conservation
- Energy conservation
- Waste products management
- Efficiency per laundry load
- Fabric lifetime cost
These issues apply in all commercial laundry settings, branging from hospitals and institutional care to hospitality installations and for-profit commercial laundries. The number of commercial laundering facilities in the United States alone was estimated in 2003 at 140,400, categorized in Table 1 (ClearWater Tech, 2003).
Starting in the mid-to-late 1980s, work began to determine if ozone, O3, a known powerful oxidant and disinfectant, would allow laundering to be performed using ambient temperature water. The strong oxidizing and bleaching properties of ozone might allow reduction or even elimination of laundering detergents, thus lowering the chemical loads in discharge wastewaters. Simultaneously, ozone’s strong disinfecting capabilities might also kill or inactivate problematic microorganisms found in many soiled textiles, e.g., from hospitals, medical facilities, nursing homes, etc.
Two remarkable properties of ozone stand out in its application to laundry systems:
1. Because it leaves no chemical residue and because the amount of detergent needed with ozone treatment is much lower, ozone-sanitized wash needs far less rinsing, saving water; and,
2. Because ozone works so efficiently in cold water, sanitizing as well as cleaning can be done in cold water, saving energy.
With less rinsing, wash loads can be completed faster, thus utilizing the laundry equipment more efficiently and reducing the total staff hours per load. Ozone’s arrival for commercial laundries has proceeded on a normal innovation-adoption path.
In the United Kingdom, rapid and significant advances in developing the application of ozone in commercial laundries have been made in recent years. A leader in this effort has been JLA, Limited, of Ripponden, West Yorkshire, that has been marketing ozone systems to the institutional laundry business since mid-2004. The primary purpose of this publication is to document results from studies conducted by independent microbiological laboratories and other organizations to document the various aspects of ozone’s application in commercial laundering equipment. Another objective is to document and quantify the cost savings obtainable by utilizing this revolutionary technology in commercial laundries.