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BACKGROUND The kaolin flocculant activities of bovine blood (BB) and hemoglobin (HEM) at different salt and pH values were determined. Lower limit concentration (LLC), window of application (WA), and degrees of clarification (DC) values for BB and HEM were determined and compared with those of the synthetic polymeric flocculants poly(diallydimethylammonium chloride) (PDADMAC), cationic polyacrylamide (PAM), and anionic PAM. BB flocculation of lignin, a bioproduct of biomass conversion to bioethanol, was demonstrated. RESULTS Flocculation of kaolin by BB and HEM increased at acidic pH and in the presence of NaCl. LLC values of HEM and BB were similar to LLC values of cationic and anionic PAM. LLC values of HEM and BB were 18–20‐fold higher than that of PDDMAC. WA values of BB and HEM were similar to those of PDADMAC, cationic PAM, and anionic PAM. For lignin flocculation, the ratio of LLC for BB/PDADMAC was 20–38, but the ratio of WA for BB/PDADMAC was > 3.6. For kaolin and lignin flocculation, DC values were similar for all flocculants. CONCLUSIONS The renewable flocculants BB and HEM rapidly settle kaolin and lignin suspensions; BB and HEM could be used in the process to separate lignin from other biomass components. Published 2014. This article is a U.S. Government work and is in the public domain in the USA

669 (1980). In order to obtain further understanding of the nature of lignin reactions during autocatalysed hydrolysis (autohydrolysis) of wood, milled wood lignin (MWL) was isolated from aspen (Populus tremuloides) and treated under autohydrolysis conditions. By this means reactions of the lignin itself could be distinguished from those taking place between lignin and the carbohydrate or other components of the wood. The material after the reaction was separated into a dioxane insoluble fraction (DI), a dioxane soluble but ether insoluble fraction (DSEI), and an ether soluble fraction (ES). Studies were carried out on the DI and DSEI fractions; no direct study was made of the small ES fraction.The formation of DI material increased linearly during the first 7.5 min at 170°C and then levelled off. At the same time DSEI decreased and then levelled off. Gel permeation chromatography of the DSEI fraction suggested that during autohydrolysis there is an initial generation of low molecular weight fragments which recombine to form first a high molecular weight soluble fraction and from this the insoluble product. The DSEI fraction contained increased conjugated and unconjugated keto groups. Carboxylic acids were also detected; they have been attributed to the reincorporation of low molecular weight aromatic acids generated by the hydrolysis of the corresponding esters. The dioxane insoluble (DI) fraction had fewer unconjugated keto groups than the DSEI fraction, indicating that these groups participated in the condensation reactions leading to the formation of insoluble material. These probably involve position 6 of the aromatic ring. JAIRO H. LORA et MORRIS WAYMAN. Can. J. Chem. 58,669 (1980). Dans le but d'obtenir de plus amples informations sur la nature des reactions de la lignine lors de I'hydrolyse autocatalysee (autohydrolyse) du bois, on a isole du peuplier (Populus tremuloides) la lignine de bois moulu (LBM) et on l'a soumise a une autohydrolyse. Par ces reactions de la lignine on peut distinguer celles qui ont lieu entre la lignine et les carbohydrates ou d'autres derives du bois. Les produits de la reaction sont separes en fraction insoluble dans le dioxanne (ID), fraction soluble dans le dioxanne mais insoluble dans l'tther (SDIE) et en une fraction soluble dans l'ether (SE). On a etudie les fractions ID et SDIE mais on n'a pas fait d'etudes directes sur la petite fraction SE.La formation de produits ID augmente lineairement durant les 7.5 premieres minutes puis se stabilise. En mcme temps la fraction §DIE dirninue puis se stabilise. La chromatographie sur gel de la fraction SDIE suggere que lors de l'autohydrolyse il y aformation initiale de fragments de faibles poids moleculaires qui se recombinent d'abord pour donner la fraction soluble de poids moleculaire eleve e t a partir duquel se forme le produit insoluble. La fraction SDIE contient des groupes cetoniques conjugues et non conjugues. On a egalement decele des acides carboxyliques et on les attribue a la reincorporation d'acides aromatiques de faib...