Batch and continuous reactor treatment of black liquor from pulp and paper mill wastewater. (Water Quality and Treatment 02:00 PM, Saturday, April 5, 2003 Brewer/Frost Science 138 Dr. Yung-Tse Hung-Presiding).

Hung, Yung-Tse ; Peddibovina, Sai Srinivas Kumar

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This paper describes a study on the treatment of black liquor from a kraft pulp and paper mill using batch and continuous biological reactors. The objective of the study was to determine the removal efficiency of COD (chemical oxygen demand) from black liquor from a kraft pulp and paper mill wastewater by biological treatment processes using Aeromonas formicans. Batch and continuous activated sludge reactors were used in the study. Compressed air was used for mixing and for providing dissolved oxygen for bio-oxidation in the reactors. The black liquor had 11.36 pH, 5400 mg/L COD, 7640 color unit, 2.18 mg/L lignin. The results of batch studies showed that the strain, Aeromonas formicans, removed 71% of COD and 78% of lignin, and 86% color during 10 days of hydraulic detention time. The removal efficiency of COD, color and lignin obtained in continuous reactor studies was 73, 88, and 77%, respectively, during 8 days of hydraulic detention time. First order kinetics was observed for COD, color and lignin removal. The kinetic coefficient, k, was 0.43, 0.60, and 0.55 [day.sup.-1] for COD, color, and lignin, respectively. A linear relationship was observed between COD and lignin removal efficiency, and between color and lignin removal efficiency. Results indicated that the bacterial strain used in the study was effective in removing COD, color and lignin from black liquor in pulp and paper mill wastewater.

YUNG-TSE HUNG Y.HUNG@CSUOHIO.EDU AND SAI SRINIVAS KUMAR PEDDIBOVINA SAISRINIVAS33@YAHOO.COM, CIVIL AND ENVIRONMENTAL ENGINEERING DEPT, CLEVELAND STATE UNIVERSITY, CLEVELAND OH 44115-2214