Gönder Z Beril, Balcıoğlu Gökhan, Vergili Ilda, Kaya Yasemin
Istanbul University, Faculty of Engineering, Department of Environmental Engineering, Avcilar Campus, Avcilar, 34320, Istanbul, Turkey.
Istanbul University, Faculty of Engineering, Department of Environmental Engineering, Avcilar Campus, Avcilar, 34320, Istanbul, Turkey.
J Environ Manage. 2017 Sep 15;200:380-390. doi: 10.1016/j.jenvman.2017.06.005. Epub 2017 Jun 7.
The present study was conducted to investigate the electrochemical treatment of carwash wastewater using electrocoagulation (EC) process with Fe and Al electrodes. The effects of operating conditions such as initial pH (2-10), current density (0.1-5 mA/cm) and operating time (5-50 min) on chemical oxygen demand (COD), oil-grease, chloride removal efficiencies as well as total operating costs were studied. The optimum conditions that achieve higher removal efficiencies were found as pH: 8, current density: 3 mA/cm, operating time: 30 min for Fe electrode and pH: 6, current density: 1 mA/cm, operating time: 30 min for Al electrode. The removal efficiencies for COD, oil-grease and chloride were obtained as 88%, 90% and 50% for Fe and 88%, 68% and 33% for Al electrodes under the optimum conditions. The total operating costs at the optimum conditions were calculated as 0.6 $/m and 0.3 $/m for Fe and Al electrodes, respectively. The sludge samples generated after EC process were characterized with Fourier transform infrared (FTIR) spectroscopy and zeta potential measurements for both electrodes. The analyses showed the presence of hydroxides and oxyhydroxides in the sludge samples and the surface of the sludge samples was negatively charged in the wide range of pH. As a conclusion, this study revealed that EC process using Fe electrode should be a feasible technology for higher COD and oil-grease removals from carwash wastewaters.
本研究旨在探讨采用铁和铝电极的电凝聚（EC）工艺对洗车废水进行电化学处理。研究了初始pH值（2 - 10）、电流密度（0.1 - 5 mA/cm）和运行时间（5 - 50分钟）等操作条件对化学需氧量（COD）、油类和油脂、氯离子去除效率以及总运行成本的影响。发现实现较高去除效率的最佳条件为：铁电极时，pH值为8，电流密度为3 mA/cm，运行时间为30分钟；铝电极时，pH值为6，电流密度为1 mA/cm，运行时间为30分钟。在最佳条件下，铁电极对COD、油类和油脂以及氯离子的去除效率分别为88%、90%和50%，铝电极分别为88%、68%和33%。最佳条件下铁电极和铝电极的总运行成本分别计算为0.6美元/立方米和0.3美元/立方米。对电凝聚过程后产生的污泥样品进行了傅里叶变换红外（FTIR）光谱和zeta电位测量，以表征两个电极的情况。分析表明污泥样品中存在氢氧化物和羟基氧化物，并且在较宽的pH范围内污泥样品表面带负电荷。总之，本研究表明使用铁电极的电凝聚工艺对于从洗车废水中高效去除COD和油类及油脂应是一种可行的技术。
