title: A combined adsorption and flocculation process for producing lignocellulosic complexes from spent liquors of neutral sulfite semichemical pulping process.
abstract: The spent liquor (SL) of a neutral sulfite semichemical pulping process contains lignocelluloses that are currently treated in a waste water system. In this work, an adsorption process using activated carbon (AC) was considered for isolating the lignin and hemicelluloses from SL. The maximum adsorptions of 0.9 g/g lignin and 0.43 g/g of hemicelluloses on AC were achieved under the conditions of 30°C, pH 7 and 3h with SL/AC weight ratio of 90. The addition of polydiallyldimethylammonium chloride (PDADMAC) to the SL/AC system significantly improved the adsorption of lignin to 2.5 g/g on AC. The molecular weight of PDADMAC considerably affected the results in that the higher MW PDADMAC led to less lignin, but more hemicelluloses, turbidity and chemical oxygen demand removals from the SL. The thermal analysis also revealed that the higher MW PDADMAC generated precipitates with a lower incineration temperature and heating value.
authors.affiliation: Biology Department, University of Guelph, 50 Stone Road East, Guelph, Ontario N1G 2W1, Canada; Chemical Engineering Department, Lakehead University, 955 Oliver Road, Thunder Bay, Ontario P7E 5E1, Canada.
authors.forename: Mehdi
authors.initials: M
authors.lastname: Dashtban
authors.affiliation: Chemical Engineering Department, Lakehead University, 955 Oliver Road, Thunder Bay, Ontario P7E 5E1, Canada.
authors.forename: Allan
authors.initials: A
authors.lastname: Gilbert
authors.affiliation: Chemical Engineering Department, Lakehead University, 955 Oliver Road, Thunder Bay, Ontario P7E 5E1, Canada. Electronic address: pfatehi@lakeheadu.ca.
authors.forename: Pedram
authors.initials: P
authors.lastname: Fatehi
mesh_terms: D000327:Adsorption; D057919:Biological Oxygen Demand Analysis; D001709:Biotechnology / Q000379:methods*; D002606:Charcoal / Q000737:chemistry; D005427:Flocculation; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008031:Lignin / Q000138:chemical synthesis* / Q000302:isolation & purification; D008970:Molecular Weight; D009391:Nephelometry and Turbidimetry; D010209:Paper; D011095:Polyethylenes / Q000737:chemistry; D011134:Polysaccharides / Q000302:isolation & purification; D000644:Quaternary Ammonium Compounds / Q000737:chemistry; D013447:Sulfites / Q000737:chemistry*; D013696:Temperature; D013818:Thermogravimetry
chemical_list: D011095:Polyethylenes; D011134:Polysaccharides; D000644:Quaternary Ammonium Compounds; D013447:Sulfites; C036909:lignocellulose; D002606:Charcoal; C041004:poly-N,N-dimethyl-N,N-diallylammonium chloride; C007916:hemicellulose; D008031:Lignin
keywords: Adsorption; Biorefinery; Hemicellulose; Lignin; NSSC