title: Treatment of papermaking tobacco sheet wastewater by electrocoagulation combined with electrochemical oxidation.
abstract: 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.
authors.affiliation: School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310018, China E-mail: maxj@mail.zjgsu.edu.cn.
authors.forename: Xiangjuan
authors.initials: X
authors.lastname: Ma
authors.affiliation: School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310018, China E-mail: maxj@mail.zjgsu.edu.cn; School of Environment, Tsinghua University, Beijing 100084, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Gao
authors.affiliation: Department of Production and Management, Hangzhou Liqun Environment-protecting Paper Co., Ltd, Hangzhou 310018, China.
authors.forename: Hanping
authors.initials: H
authors.lastname: Huang
mesh_terms: D001673:Biodegradation, Environmental; D057919:Biological Oxygen Demand Analysis; D055664:Electrochemical Techniques / Q000379:methods*; D007220:Industrial Waste / Q000032:analysis*; D009930:Organic Chemicals; D010084:Oxidation-Reduction; D014026:Nicotiana; D014865:Waste Disposal, Fluid / Q000379:methods; D062065:Wastewater / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000737:chemistry
chemical_list: D007220:Industrial Waste; D009930:Organic Chemicals; D062065:Wastewater; D014874:Water Pollutants, Chemical