Biofilms have adverse effects on all types of instruments, sensors, and equipment used in industrial settings, including power plants, food and beverage production plants, desalination facilities, and paper mills. Biofilm on pipelines, tanks, heat exchangers, RO membranes, and other equipment can cause reduction of heat transfer, increased pressure drop and corrosion of metallic surfaces, and can also be a source for contamination. Biofilms have also shown resistance to treatment, creating an ongoing challenge for industrial engineers and instrument designers. Productivity loss coupled with increased costs of equipment cleaning and replacement has made biofilm prevention a serious problem across industries. Control of fouling in water intakes, piping systems and desalination plants cost over $15 billion per year. In a power plant, biofouling can directly increase the cost of capital equipment, wastewater treatment, and operations.
The process of biofilm formation begins with the attachment of a conditioning film on a surface followed by the initial microbial attachment. This progresses into an irreversible adhesion where the microbe cells become attached not only to the surface, but to each other to form a biofilm matrix. In favorable conditions, the biofilm growth will continue with some cells detaching over time.
Traditional methods of biofilm prevention
There are a variety of traditional means of biofilm prevention and control, including both chemical treatment and mechanical removal of films. The water treatment industry has traditionally relied on the use of chemicals to reduce microbial counts. Many protocols include the removal of loose debris with water followed by the use of chemical agents, rinsing and disinfection. Mechanical methods have also been used in water treatment—including water turbulence and scrubbing—to free surfaces of microbial growth. However, these films are difficult to fully remove with these methods as the bacteria are not killed, and thus can redeposit in other locations in the system, possibly to reform a new biofilm matrix.
UVC disinfection: A new solution
Because of the limitations and ineffectiveness of chemical and mechanical methods, as well as a desire to reduce costs, industries across the board are seeking alternative methods to prevent the formation of biofilm. One promising disinfection technology is UV irradiation.
Although the potential of UV irradiation for biofilm prevention has been known for some time, traditional UV lamps containing mercury are often not a feasible option due to their bulk, fragility, and high power consumption. Also the risk of unintended discharge of toxic mercury has eliminated this option for many industries. Crystal IS UVC LEDs offer several advantages in preventing biofilm formation.
- Non-toxic solution for disinfection
- Small footprint for design flexibility
- Low power consumption compared to mercury lamps
- Can be operated with a duty cycle to optimize lifetime