In the present work, advanced treatment of carwash wastewater with an integrated electrocoagulation-nanofiltration (EC-NF) process to reuse the treated wastewater as rinsing water was investigated. The wastewater was pretreated by EC process under various operating parameters such as temperature (25 °C, 35 °C, 45 °C), stirring speed (150 rpm, 250 rpm, 350 rpm), and electrode connection mode (MP-P, MP-S, BP-S) using Fe electrode. The best results were achieved at 25 °C, 250 rpm and MP-P connection mode for EC, considering both pollutant removals and energy consumptions. EC sludge was characterized scanning electron microscopy-energy dispersive index (ESEM-EDX) analysis. The pretreated carwash wastewater using EC process was further treated by NF process using NF 270 and Desal 5DL membranes. Desal 5 DL membrane provided the highest treatment performance for chloride (92%), conductivity (80%) and total hardness (90%) parameters for EC-NF process. Resistance in series model was used for a deeper discussion of the reasons for flux decline. In addition, Fourier transform infrared (FTIR) spectroscopy and contact angle measurements were conducted for membrane fouling characterization. The foulants mainly accumulated on the membrane surface forming a cake layer and lower extent of membrane fouling was occurred for both membranes. As a result, this study showed that the water quality for reuse in carwashing process could be achieved with an integrated EC-NF process.

中文翻译：

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集成的电凝-纳滤工艺，可用于洗车废水的再利用。

在目前的工作中，研究了采用电凝聚-纳滤（EC-NF）综合工艺对洗车废水进行深度处理的方法，以将处理后的废水作为冲洗水重复使用。通过EC工艺在各种操作参数下对废水进行预处理，例如温度（25°C，35°C，45°C），搅拌速度（150 rpm，250 rpm，350 rpm）和电极连接模式（MP-P， MP-S，BP-S）使用铁电极。考虑到污染物去除和能耗，在25°C，250 rpm和MP-P连接模式下获得最佳效果的EC。EC污泥的特征在于扫描电子显微镜-能量色散指数（ESEM-EDX）分析。使用EC工艺的预处理洗车废水通过使用NF 270和Desal 5DL膜的NF工艺进一步处理。Desal 5 DL膜对EC-NF工艺的氯化物（92％），电导率（80％）和总硬度（90％）参数提供了最高的处理性能。串联电阻模型用于更深入地讨论通量下降的原因。此外，进行了傅里叶变换红外（FTIR）光谱和接触角测量，以表征膜污染。污垢主要聚集在形成滤饼层的膜表面上，并且两种膜的污垢程度均较低。结果，这项研究表明，通过集成的EC-NF工艺可以实现洗车过程中回用的水质。串联电阻模型用于更深入地讨论通量下降的原因。此外，进行了傅里叶变换红外（FTIR）光谱和接触角测量，以表征膜污染。污垢主要聚集在形成滤饼层的膜表面上，并且两种膜的污垢程度均较低。结果，这项研究表明，通过集成的EC-NF工艺可以实现洗车过程中回用的水质。串联电阻模型用于更深入地讨论通量下降的原因。此外，进行了傅里叶变换红外（FTIR）光谱和接触角测量，以表征膜污染。污垢主要聚集在形成滤饼层的膜表面上，并且两种膜的污垢程度均较低。结果，这项研究表明，通过集成的EC-NF工艺可以实现洗车过程中回用的水质。