Enhancing pulp and paper mill biosludge dewaterability using enzymes

• Published in: Water Research
• Main Authors: Bonilla, Sofia, Tran, Honghi, Allen, D. Grant
• Format: Other/Unknown Material
• Language: English
• Published: University of Toronto 2015
• Subjects: sludge; dewatering; enzymes; proteins; pulp mill; Canada; Eldorado; Wilcox; Peace River
• Online Access: http://hdl.handle.net/1807/111085; https://doi.org/10.1016/j.watres.2014.10.057

There have been limited studies on the potential use of enzymes for enhancing the dewaterability of biosludge. The mechanisms for such enhancement have not been investigated despite the environmental advantages of using enzymes over synthetic polymers for biosludge conditioning. In order to find enzymes with this potential, a screening of commercially available enzymes was carried out using capillary suction time to assess biosludge dewaterability. The only enzyme that showed dewatering improvements in the screening tests was a lysozyme which reduced the capillary suction time by 36% and increased the cake solids content from 5.6 to 8.9 DS%. Lysozyme aided in the flocculation of particles reducing the polymer demand from 11% to 6%. Active and inactive lysozyme exhibited a similar ability for enhancing sludge dewatering, indicating that the conditioning mechanism of lysozyme is similar to that of a flocculant. This work was part of the research program on “Increasing Energy and Chemical Recovery Efficiency in the Kraft Process”, jointly supported by the Natural Sciences and Engineering Research Council of Canada (NSERC) and a consortium of the following companies: Andritz, AV Nackawic, Babcock & Wilcox, Boise, Carter Holt Harvey, Celulose Nipo-Brasileira, Clyde-Bergemann, DMI Peace River Pulp, Eldorado, ERCO Worldwide, Fibria, FP Innovations, International Paper, Irving Pulp & Paper, Kiln Flame Systems, Klabin, MeadWestvaco, StoraEnso Research, Suzano, Tembec, Tolko Industries and Valmet. The authors also thank the Ontario Government for supporting this project.