Isolation and Irradiation-Modification of Lignin Specimens from Black Liquor and Evaluation of Their Effects on Wastewater Purification

Ke-Qin Wang, Jing-Ping Chen, Liang Chen, Xiao-Fen Wu, Xiao-Jun Su, Samuel Amartey, Wensheng Qin

Abstract


In this study, crude lignin extracted from the black liquor generated by a pulp and paper mill was modified by different doses of irradiation. The crude and irradiation-modified lignins were used to treat wastewater that was generated during the production of starch glucoamylase. Changes to the physical and chemical properties and structure of the irradiation-modified lignins were determined using scanning electron microscopy, solubility analysis, elemental analysis, analysis of phenolic hydroxyl group, ultraviolet–visible spectroscopy, and Fourier transform infrared spectroscopy. Irradiation reduced the phenolic hydroxyl content in the lignin but increased its solubility by about 40%; analysis revealed that irradiation also destroyed the skeletal structure of the benzene ring in the lignin. After four minutes of settling, the total nitrogen (TN) and chemical oxygen demand (COD) in the wastewater reached 7.0 mg/L and 1573.1 mg/L, respectively. The settled solids content and protein recovery were 1.12 g/L and 98%, respectively. This study suggested that irradiation-modified lignin extracted from black liquor generated in the pulp and paper industry can be used to treat wastewater from the production of starch glucoamylase.

Keywords


Black liquor; Irradiation modification; Lignin; Wastewater treatment

Full Text: PDF

Welcome to BioResources! This online, peer-reviewed journal is devoted to the science and engineering of biomaterials and chemicals from lignocellulosic sources for new end uses and new capabilities. The editors of BioResources would be very happy to assist you during the process of submitting or reviewing articles. Please note that logging in is required in order to submit or review articles. Martin A. Hubbe, (919) 513-3022, hubbe@ncsu.edu; Lucian A. Lucia, (919) 515-7707, lucian.lucia@gmail.com URLs: bioresourcesjournal.com; http://ncsu.edu/bioresources ISSN: 1930-2126