{"id":{"repo_id":"toronto-retro","oai_identifier":"oai:utoronto.scholaris.ca:1807/127972"},"canonical_url":"https://search.dev.ndltd.org/etd/toronto-retro/oai:utoronto.scholaris.ca:1807/127972","repository":{"repo_id":"toronto-retro","name":"University of Toronto","base_url":"https://utoronto.scholaris.ca/server/oai/request"},"display":{"title":"The Effect of Using Bioflocculants as Conditioners on Dewatering of Biosludge","abstract":"Chemical conditioning by biopolymers, as an alternative for petroleum-based synthetic polymers, for improving the dewatering of biosludge from pulp and paper mills is a growing interest. There are limited studies on the application of biopolymers for enhancing the dewaterability of biosludge and the underlying mechanisms in this process. This thesis explored the possibility of employing biopolymers such as hemoglobin (Hb), lignin-based flocculants (LBFs), and protamine to enhance the dewaterability.Cationic polymers improve the dewaterability of sludge by neutralizing the negative charge of the biosludge particles. Biopolymers such as hemoglobin and lignin do not possess high charge density naturally. As a result, they only exhibit a positive effect on dewaterability after modification through different processes. Hemoglobin from animal blood was methylated to replace the hydrogen carboxyl groups in its structure to become more positively charged. Lignin from pulp manufacturing processes was also modified via free radical polymerization with acrylate-based monomers. Dewaterability was assessed based on the dry solids content after treatment and pressing by Crown press. Capillary suction time (CST) was also used as water separation rate indicator. Only after modification, by using 10% of methylated hemoglobin, the dry solids content of biosludge increased by 5%. Similarly, LBFs considerably decreased the CST by nearly 50 seconds from 73s to 23s and increased the dry solids content by 7% with a relatively high dose of 7.5%. The potential of using dual conditioning method by combining cationic biopolymers such as protamine and LBFs with a small amount of a synthetic anionic polyacrylamide (APAM) was also investigated to lower the dosage required for biopolymers. Dual conditioning provided significant synergistic effect resulting in increasing the solids content of biosludge by 9% and lowering the amount of protamine addition substantially to 2%. In a similar way for LBFs, the biopolymer demand decreased from 7.5% to around 3% by using a dual conditioning system. The cationic biopolymer reduced the negative charge on the particles, allowing smaller particles to agglomerate and provided a positively charged framework for the addition of the APAM. Significant floc-bridging occurred after the addition of APAM, allowing smaller flocs to aggregate into larger flocs.","abstract_html":"Chemical conditioning by biopolymers, as an alternative for petroleum-based synthetic polymers, for improving the dewatering of biosludge from pulp and paper mills is a growing interest. There are limited studies on the application of biopolymers for enhancing the dewaterability of biosludge and the underlying mechanisms in this process. This thesis explored the possibility of employing biopolymers such as hemoglobin (Hb), lignin-based flocculants (LBFs), and protamine to enhance the dewaterability.Cationic polymers improve the dewaterability of sludge by neutralizing the negative charge of the biosludge particles. Biopolymers such as hemoglobin and lignin do not possess high charge density naturally. As a result, they only exhibit a positive effect on dewaterability after modification through different processes. Hemoglobin from animal blood was methylated to replace the hydrogen carboxyl groups in its structure to become more positively charged. Lignin from pulp manufacturing processes was also modified via free radical polymerization with acrylate-based monomers. Dewaterability was assessed based on the dry solids content after treatment and pressing by Crown press. Capillary suction time (CST) was also used as water separation rate indicator. Only after modification, by using 10% of methylated hemoglobin, the dry solids content of biosludge increased by 5%. Similarly, LBFs considerably decreased the CST by nearly 50 seconds from 73s to 23s and increased the dry solids content by 7% with a relatively high dose of 7.5%. The potential of using dual conditioning method by combining cationic biopolymers such as protamine and LBFs with a small amount of a synthetic anionic polyacrylamide (APAM) was also investigated to lower the dosage required for biopolymers. Dual conditioning provided significant synergistic effect resulting in increasing the solids content of biosludge by 9% and lowering the amount of protamine addition substantially to 2%. In a similar way for LBFs, the biopolymer demand decreased from 7.5% to around 3% by using a dual conditioning system. The cationic biopolymer reduced the negative charge on the particles, allowing smaller particles to agglomerate and provided a positively charged framework for the addition of the APAM. Significant floc-bridging occurred after the addition of APAM, allowing smaller flocs to aggregate into larger flocs.","abstract_has_math":false,"creators":["Ghazisaidi, Hamed"],"institution":null,"degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":"Chemical Engineering Applied Chemistry","school":null,"contributors":[],"advisors":["Allen, Grant DGA","Tran, Honghi HT"],"committee_chairs":[],"committee_members":[],"year":2023,"date_issued":"2023-06","date_published":"2023-06","updated_at":"2026-07-27T21:28:20Z","subjects":["Bio-flocculant","Biosludge","Dewatering","Pulp Paper","Wastewater"],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/1807/127972","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Allen, Grant DGA","Tran, Honghi HT"]},{"key":"dc:contributor.department","label":"Department","values":["Chemical Engineering Applied Chemistry"]},{"key":"dc:creator","label":"Author","values":["Ghazisaidi, Hamed"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2023-06"]},{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2023-06-27T15:41:05Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2023-06-27T15:41:05Z"]},{"key":"dc:date.issued","label":"Date","values":["2023-06"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Bio-flocculant","Biosludge","Dewatering","Pulp Paper","Wastewater"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/1807/127972"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Chemical conditioning by biopolymers, as an alternative for petroleum-based synthetic polymers, for improving the dewatering of biosludge from pulp and paper mills is a growing interest. There are limited studies on the application of biopolymers for enhancing the dewaterability of biosludge and the underlying mechanisms in this process. This thesis explored the possibility of employing biopolymers such as hemoglobin (Hb), lignin-based flocculants (LBFs), and protamine to enhance the dewaterability.Cationic polymers improve the dewaterability of sludge by neutralizing the negative charge of the biosludge particles. Biopolymers such as hemoglobin and lignin do not possess high charge density naturally. As a result, they only exhibit a positive effect on dewaterability after modification through different processes. Hemoglobin from animal blood was methylated to replace the hydrogen carboxyl groups in its structure to become more positively charged. Lignin from pulp manufacturing processes was also modified via free radical polymerization with acrylate-based monomers. Dewaterability was assessed based on the dry solids content after treatment and pressing by Crown press. Capillary suction time (CST) was also used as water separation rate indicator. Only after modification, by using 10% of methylated hemoglobin, the dry solids content of biosludge increased by 5%. Similarly, LBFs considerably decreased the CST by nearly 50 seconds from 73s to 23s and increased the dry solids content by 7% with a relatively high dose of 7.5%. The potential of using dual conditioning method by combining cationic biopolymers such as protamine and LBFs with a small amount of a synthetic anionic polyacrylamide (APAM) was also investigated to lower the dosage required for biopolymers. Dual conditioning provided significant synergistic effect resulting in increasing the solids content of biosludge by 9% and lowering the amount of protamine addition substantially to 2%. In a similar way for LBFs, the biopolymer demand decreased from 7.5% to around 3% by using a dual conditioning system. The cationic biopolymer reduced the negative charge on the particles, allowing smaller particles to agglomerate and provided a positively charged framework for the addition of the APAM. Significant floc-bridging occurred after the addition of APAM, allowing smaller flocs to aggregate into larger flocs."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["Ph.D."]},{"key":"dc:title","label":"Title","values":["The Effect of Using Bioflocculants as Conditioners on Dewatering of Biosludge"]}]}],"canonical_facts":{"dc:contributor.advisor":["Allen, Grant DGA","Tran, Honghi HT"],"dc:contributor.department":["Chemical Engineering Applied Chemistry"],"dc:creator":["Ghazisaidi, Hamed"],"dc:date":["2023-06"],"dc:date.accessioned":["2023-06-27T15:41:05Z"],"dc:date.available":["2023-06-27T15:41:05Z"],"dc:date.issued":["2023-06"],"dc:description.abstract":["Chemical conditioning by biopolymers, as an alternative for petroleum-based synthetic polymers, for improving the dewatering of biosludge from pulp and paper mills is a growing interest. There are limited studies on the application of biopolymers for enhancing the dewaterability of biosludge and the underlying mechanisms in this process. This thesis explored the possibility of employing biopolymers such as hemoglobin (Hb), lignin-based flocculants (LBFs), and protamine to enhance the dewaterability.Cationic polymers improve the dewaterability of sludge by neutralizing the negative charge of the biosludge particles. Biopolymers such as hemoglobin and lignin do not possess high charge density naturally. As a result, they only exhibit a positive effect on dewaterability after modification through different processes. Hemoglobin from animal blood was methylated to replace the hydrogen carboxyl groups in its structure to become more positively charged. Lignin from pulp manufacturing processes was also modified via free radical polymerization with acrylate-based monomers. Dewaterability was assessed based on the dry solids content after treatment and pressing by Crown press. Capillary suction time (CST) was also used as water separation rate indicator. Only after modification, by using 10% of methylated hemoglobin, the dry solids content of biosludge increased by 5%. Similarly, LBFs considerably decreased the CST by nearly 50 seconds from 73s to 23s and increased the dry solids content by 7% with a relatively high dose of 7.5%. The potential of using dual conditioning method by combining cationic biopolymers such as protamine and LBFs with a small amount of a synthetic anionic polyacrylamide (APAM) was also investigated to lower the dosage required for biopolymers. Dual conditioning provided significant synergistic effect resulting in increasing the solids content of biosludge by 9% and lowering the amount of protamine addition substantially to 2%. In a similar way for LBFs, the biopolymer demand decreased from 7.5% to around 3% by using a dual conditioning system. The cationic biopolymer reduced the negative charge on the particles, allowing smaller particles to agglomerate and provided a positively charged framework for the addition of the APAM. Significant floc-bridging occurred after the addition of APAM, allowing smaller flocs to aggregate into larger flocs."],"dc:description.degree":["Ph.D."],"dc:identifier.uri":["http://hdl.handle.net/1807/127972"],"dc:subject":["Bio-flocculant","Biosludge","Dewatering","Pulp Paper","Wastewater"],"dc:title":["The Effect of Using Bioflocculants as Conditioners on Dewatering of Biosludge"],"dc:type":["Thesis"]},"updated_at":"2026-07-27T21:28:20Z"}