Ma Xiangjuan, Gao Yang, Huang Hanping
School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310018, China E-mail:
Department of Production and Management, Hangzhou Liqun Environment-protecting Paper Co., Ltd, Hangzhou 310018, China.
Water Sci Technol. 2015;71(8):1165-72. doi: 10.2166/wst.2015.057.
Attempts were made in this study to examine the efficiency of electrocoagulation (EC) using aluminum (Al) anode and stainless steel net cathode combined with electrochemical oxidation with a β-PbO₂anode or a mixed metal oxide (MMO) anode for treatment of papermaking tobacco sheet wastewater, which has the characteristics of high content of suspended solids (SS), intensive color, and low biodegradability. The wastewater was first subjected to the EC process under 40 mA/cm² of current density, 2.5 g/L of NaCl, and maintaining the original pH of wastewater. After 6 minutes of EC process, the effluent was further treated by electrochemical oxidation. The results revealed that the removal of SS during the EC process was very beneficial to mass transfer of organics during electrochemical oxidation. After the combined process, 83.9% and 82.8% of chemical oxygen demand (COD) removal could be achieved on the β-PbO₂and MMO anodes, respectively. The main components of the final effluent were biodegradable organic acids, such as acetic acid, propionic acid, butyric acid, valeric acid, and hexahyl carbonic acid; the 5-day biochemical oxygen demand/chemical oxygen demand (BOD₅/COD) ratio increased from 0.06 to 0.85 (Al + β-PbO₂) or 0.80 (Al + MMO). Therefore, this integrated process is a promising alternative for pretreatment of papermaking tobacco sheet wastewater prior to biological treatment.
本研究尝试考察使用铝（Al）阳极和不锈钢网阴极的电凝聚（EC）与β-PbO₂阳极或混合金属氧化物（MMO）阳极的电化学氧化相结合处理造纸烟草薄片废水的效率，该废水具有悬浮固体（SS）含量高、颜色深和生物降解性低的特点。废水首先在电流密度40 mA/cm²、NaCl浓度2.5 g/L且保持废水初始pH值的条件下进行电凝聚过程。电凝聚过程6分钟后，出水进一步进行电化学氧化处理。结果表明，电凝聚过程中SS的去除对电化学氧化过程中有机物的传质非常有利。经过联合处理后，在β-PbO₂阳极和MMO阳极上分别可实现83.9%和82.8%的化学需氧量（COD）去除率。最终出水的主要成分是可生物降解的有机酸，如乙酸、丙酸、丁酸、戊酸和己二酸；五日生化需氧量/化学需氧量（BOD₅/COD）比值从0.06提高到0.85（Al + β-PbO₂）或0.80（Al + MMO）。因此，这种集成工艺是造纸烟草薄片废水生物处理前预处理的一种有前景的替代方法。
