电絮凝-超滤除氟控铝工艺参数优化

电絮凝-超滤（electrocoagulation-ultrafiltration process，EC-UF）工艺在饮用水除氟方面具有良好的应用前景，但是存在着能耗较高和出水余铝不达标的问题。实验通过优化电絮凝参数和pH，解决了EC-UF工艺能耗高和出水余铝不达标问题。主要考察了电絮凝pH、电流密度、水力停留时间、初始氟浓度对氟离子的去除效果以及膜污染的控制情况，并分析了铝络合物对氟的去除机理。结果表明，在电流密度10 A·m-2、水力停留时间30 min、pH在6.0~7.0的最佳工艺条件下，EC-UF工艺的出水氟、余铝含量均可达到生活饮用水水质标准。与传统工艺相比，调控pH的EC-UF工艺能耗为0.467 kWh·g-1，降低了33.9%，并且具有较好的出水水质，表明pH的调控是EC-UF除氟控铝工艺优化的关键因素。

Parameters optimization on electrocoagulation-ultrafiltration process for removing fluoride and controlling residual aluminum

The electrocoagulation-ultrafiltration (EC-UF) process was widely employed in fluorine removal from drinking water. However, its further applicationwas limited due to the high energy consumption and high residual aluminum concentration in effluent. In this study, the problems of high energy consumption and the excess residual aluminum in the effluentof the EC-UF process were solved by optimizing the electrocoagulation parameters and the pH of the electro-flocculation tank. The effects of pH, current density, hydraulic retention time, initial fluorine concentration on fluoride ion removal and membrane fouling were studied, and the de-fluoride mechanism by aluminum complex was also analyzed. The results demonstrated that the concentrations of fluorine and residual aluminum in effluent of the EC-UF process met the water quality standard for drinking water under optimized conditions, such as a current density of 10 A·m-2, a HRT of 30 min and the constant pH from 6.0 to 7.0. Compared with the non-regulated pH process, theenergy consumption of pH-adjusted EC-UF process is 0.467 kWh?g-1, being reduced by 33.9%, and good effluent qualityis obtained, which indicate that pH adjustment is the key factor in EC-UF process operation.