Electrochemical degradation of acidified reed pulp black liquor with three-dimensional electrode reactor
来源期刊：中南大学学报(英文版)2015年第8期
论文作者：ZHAO Jing YE Sheng WANG Yun-yan YOU Xiang-yu CHAI Li-yuan SHU Yu-de
文章页码：2945 - 2953
Key words：black liquor; three-dimensional electrode; electro-catalytic oxidation; •OH radical; lignin
Abstract: The electrochemical degradation of reed pulp black liquor containing lignin pretreated by acidification method was investigated using a three-dimensional electrode reactor. Using activated carbon as particle electrode, the effects of pH value, reaction temperature, electrolysis time and current on residual concentration of total organic carbon (TOC) were discussed in detail. The optimal conditions were obtained: pH 2.5, influent flow rate of 200 mL/min, 25 °C, 300 mA and 2 h of electrolysis time, and the removal efficiency of TOC maintains at 35.57 %. The results of the electrochemical method indicate that •OH radicals are produced in activated carbon anode in the electrolysis process and then adsorbed on the activated carbon surface. Microcell consists of •OH radicals and the absorbed lignin. With the microcell reaction, the lignin is degraded, while the anodic polarized curve illustrates that the lignin is obviously oxidized in the anode. The contributions of direct and indirect electrolyses to the TOC removal ratio are about 50%, respectively.
ZHAO Jing(赵静)1, 2, YE Sheng(叶晟)2, 3, WANG Yun-yan(王云燕)2, YOU Xiang-yu(尤翔宇)2, CHAI Li-yuan(柴立元)2, SHU Yu-de(舒余德)2
(1. Jiangsu Transportation Institute Co., Ltd., Nanjing 210017, China;
2. School of Metallurgy and Environment, Central South University, Changsha 410083, China;
3. Jiangsu Sentay Environmental Science and Technology Co., Ltd., Nanjing 211153, China)
Abstract:The electrochemical degradation of reed pulp black liquor containing lignin pretreated by acidification method was investigated using a three-dimensional electrode reactor. Using activated carbon as particle electrode, the effects of pH value, reaction temperature, electrolysis time and current on residual concentration of total organic carbon (TOC) were discussed in detail. The optimal conditions were obtained: pH 2.5, influent flow rate of 200 mL/min, 25 °C, 300 mA and 2 h of electrolysis time, and the removal efficiency of TOC maintains at 35.57 %. The results of the electrochemical method indicate that •OH radicals are produced in activated carbon anode in the electrolysis process and then adsorbed on the activated carbon surface. Microcell consists of •OH radicals and the absorbed lignin. With the microcell reaction, the lignin is degraded, while the anodic polarized curve illustrates that the lignin is obviously oxidized in the anode. The contributions of direct and indirect electrolyses to the TOC removal ratio are about 50%, respectively.
Key words:black liquor; three-dimensional electrode; electro-catalytic oxidation; •OH radical; lignin
