Parsa J Basiri, Rezaei M, Soleymani A R
Faculty of Chemistry, Bu-Ali Sina University, Hamedan 65178, Iran.
J Hazard Mater. 2009 Sep 15;168(2-3):997-1003. doi: 10.1016/j.jhazmat.2009.02.134. Epub 2009 Mar 9.
In this research two types of electrochemical reactors for the treatment of simulated wastewaters containing Direct blue 71 azo dye (DB71) were used: (1) Laboratory scale undivided electrolysis cell system (450 mL volume) with one 2 cm x 2 cm platinum plate as the anode placed in the middle of the cell and two 2 cm x 8 cm steel plates (SS-304) as cathodes placed in the sides of the cell 2 cm from the central anode. (2) Pilot scale reactor (9L volume), equipped with two 3 cm x 23 cm stainless steel plates as anode and cathode, with distance of 3 cm apart. The influence of supporting electrolyte, applied voltage and pH were studied. The UV-vis spectra of samples during the electrochemical oxidation showed the rapid decolorization of the dye solution. During the process, the COD and current were measured in order to evaluate the degree of mineralization, energy consumption, current and anode efficiencies. The optimum supporting electrolyte and applied voltage were NaCl (5 g L(-1)) and 15 V. Using the lab scale reactor resulted in complete decolorization and mineralization of the dye solutions after ca. 90 and 120 min, respectively. Similar results were obtained using the pilot plant reactor under the same conditions. The good fit of the data to pseudo-first-order kinetics for COD removal at all applied voltages (except 20 V) was taken as proof of the involvement of indirect oxidation pathways in the process.
在本研究中，使用了两种类型的电化学反应器来处理含直接蓝71偶氮染料（DB71）的模拟废水：（1）实验室规模的无隔膜电解槽系统（体积为450 mL），其中一块2 cm×2 cm的铂板作为阳极置于电解槽中间，两块2 cm×8 cm的钢板（SS - 304）作为阴极置于距中央阳极2 cm的电解槽两侧。（2）中试规模反应器（体积为9L），配备两块3 cm×23 cm的不锈钢板分别作为阳极和阴极，两者间距为3 cm。研究了支持电解质、施加电压和pH值的影响。电化学氧化过程中样品的紫外 - 可见光谱表明染料溶液迅速脱色。在此过程中，测量了化学需氧量（COD）和电流，以评估矿化程度、能耗、电流和阳极效率。最佳支持电解质和施加电压分别为NaCl（5 g L⁻¹）和15 V。使用实验室规模的反应器时，染料溶液分别在约90分钟和120分钟后实现完全脱色和矿化。在相同条件下使用中试规模反应器也获得了类似结果。在所有施加电压下（20 V除外），数据与COD去除的准一级动力学良好拟合，这证明了间接氧化途径参与了该过程。
