Date of Award


Degree Name

Bachelor of Science


Pulp and Paper Technology


The objective of this thesis was to quantitatively determine the effects of reduced brownstock washer carryover on bleach plant effluent quality with respect to BOD and Color. More specifically; if efforts are made to reduce brownstock washer carryover by "X" pounds of BOD and Color, how many pounds of BOD and Color will be removed from the bleach plant sewer?

Very little work has been done in this area. The laboratory procedure involved extensive washing of hardwood pulp and subsequent re-introduction of weak black liquor to simulate carryover. Black liquor was added as pounds Salt Cake loss per ton pulp. The pulp was then bleached by Chlorination - Extraction, varying the Chlorine charge to obtain a 2.5 Kappa Number. The resulting bleaching effluent (combined) was analyzed for BOD5, Color, and Total Organic Carbon (TOC).