Review of Pulp and Paper Industry Experience With Biological Treatment Process Bacterial Augmentation, 1992 Environmental Conference Proceedings

Periodic reference has been made to modifying biological treatment performance through the addition of specific strains of microorganisms. Numerous advantages have been suggested such as an improvement in BODs and total suspended solids (TSS) effluent quality, reduced biological solids production, suppression of filamentous organisms in the activated sludge process, reduced foam stability and reduced chlorinated organics. A number of industry effluents, have been dosed with bacterial supplements in an effort to improve treatment. With the exception of the study summarized in this review, other known pulp and paper industry evaluation of this technique have compared treatment plant performance immediately before and after, with performance during the test period.

A bleached kraft mill located in the Northeast provided a unique opportunity to carry out a bacterial augmentation study using one of parallel and identical activated sludge plants receiving the same effluent. Specific strains of bacteria were added to one unit for approximately sixty days, with the performance of the other unit serving as a control to evaluate the bacterial inoculation. Objectives selected for the study were to determine if (a) an overall improvement in effluent quality was observed, (b) an accelerated rate of recovery following a process upset occurred, (c) improved activated sludge settleability and thickening properties were achieved, or (d) a reduction in biological sludge production occurred.

The results of the study indicated that there were no definable benefits resulting from the use of the specific bacteria used in this investigation. The experimental guidelines included in this review should, however, prove useful to others planning such studies.