Utilization of Guar Gums For White-Water BOD Reduction, 1995 Papermakers Conference Proceedings

Orlando J. Rojas & Ronald D. Neuman Auburn University, Robert J. Mills Rhône-Poulenc The effect of wet-end additives on the soluble carbohydrate concentration in papermaking white-water systems was studied by a calorimetric method. Past related studies have typically employed washed/screened pulps or model systems such as microcrystalline cellulose. However, the present investigation was conducted not only on model systems but also on whole pulp suspensions, i.e., fibers, fines and naturally present soluble sugars, hemicelluloses, etc. This approach permitted the observation of a dramatic carbohydrate “substraction” from the white water upon addition of cationic guar gum or starch. It is evident that some complexing of soluble (and colloidal) carbohydrates. fines and the wet-end additive takes place. The impact of the observed phenomenon on the reduction of effluent stream BOD and its effect on other papermaking strategies will be discussed.