Mill Performance of a Brominated Methylethylhydantoin Slimicide, 1999 Papermakers Conference Proceedings

Philip Sweeny, Michael Ludensky, Olga Borokhov

Increased papermaking alkalinity and water loop closure combined with increased efficiency and quality requirements have made the selection of a cost-effective biocide program critical to mill performance and profitability. With concurrent expanding environmental stewardship, such programs must also demonstrate minimized residual toxicity in discharge waters and in produced papers themselves.

Laboratory slimicidal testing has shown a novel brominated 5,5-methylethylhydantoin (BrMEH) to provide enhanced white water efficacy compared to other oxidizing alternatives. BrMEH enhanced efficacy is shown to be associated with enhanced white water compatibility. It is concluded that the hydantoin chemistry provided by BrMEH provides an optimal balance of compatibility and slimicidal activity.

An extended BrMEH papermill trial has shown the advantages of BrMEH to be realized in the field. A highly effective treatment regime for make-up, clarified and machine white waters was defined. BrMEH mill performance was characterized by control of aerobic and sulfate reducing bacteria (SRB) populations and maintenance of machine cleanliness. Data from three separate machines is described showing slimicidal efficacy at application rates of 0.40- 0.47 lbs/short ton (0.20-0.23 kg/metric ton).

Environmental data is presented showing the low toxicity of residual 5,5-dimethylhydantoin (DMH). In addition, laboratory results have shown BrMEH paper residuals to be below the detection limits of standard methodologies. BrMEH is thus shown to be a cost-effective, environmentally responsible, alternative slimicide for papermaking applications.