Biocide controls microbes without adverse impacts on papermaking Pulp & Paper - Find Articles

Biocide controls microbes without adverse impacts on papermaking Pulp & Paper - Find Articles: "Biocide controls microbes without adverse impacts on papermaking Pulp & Paper, Feb 2003 by Davis, Christopher K, Casini, Goffredo

A new, ammonium bromide-based biocide can control microbial populations and minimize the adverse side effects associated with strong oxidizing biocides.

For a number of years, strong oxidizers have been used to control microbial populations in the paper making industry.

Maintaining an effective level of oxidizer is not always easy or economically viable because paper process streams exhibit a high and variable 'demand' on the oxidizer.

This demand is caused by the presence of organic materials such as fiber, starch, and other colloidal or particulate organic materials in the process.

These organic materials react with and consume the oxidizer, making it much less effective at controlling microbial populations.

In order to achieve an effective oxidizer residual in high-demand systems, such as paper machines, the oxidizer must be overfed to surpass the demand in the system. Overfeeding strong oxidizers not only leads to higher treatment costs but can also cause many adverse side effects in the paper making system.

These side effects include increased consumption of dyes and other costly wet end additives (for example, optical brighteners and sizing agents), increased corrosion rates, and reduced felt life.

Some oxidizers also greatly contribute to the amount of halogenated organic compounds (AOX) produced in the papermaking process.

Furthermore, excessive residuals of certain oxidizers may be adequate for controlling microbial populations in the bulk fluid but are ineffective at controlling biofilm due to limited penetration into the biofilm matrix.1.

Strong oxidizers, such as sodium hypochlorite, are often used for biofilm control because they are considered cheap alternatives to traditional biocide programs.

However, many of the adverse side effects caused by overfeeding strong oxidizers are often overlooked. When used for biofilm control, strong oxidizers can cause more problems on the machine than they remedy.

This article describes a new, patented biocide that controls microbial populations without the adverse side effects associated with strong oxidizers.

The mode of action, application technology, and onsite production process of this new ammonium bromide-- based product are included.

Finally, case histories highlight the benefits of this new biocide."