ABSTRACT

The goal of this research is to apply an electrocoagulation process in continuous flow for the defluoridation of drinking water. Two sampling sites were studied, Temascalcingo (T), Mexico state and Jerecuaro (J), Guanajuato, with fluoride (F⁻) concentrations above the norms (2.3 mg L⁻¹ and 4.5 mg L⁻¹, respectively). In addition, a second Temascalcingo sample was enriched (T_E) to 9.2 mg L⁻¹ F⁻ to study the effect of the F⁻ concentration. A response surface design was proposed through a Box–Behnken model, and the variables studied were electrode system, flow-rate and current intensity. 51 experiments were performed with T-site to determine the best operating conditions for the system. These conditions were applied to the J-site. The experiments for T, Al/Al system achieves an F⁻ concentration within permissible limits (0.72 mg L⁻¹ F⁻) at 10 min of treatment, 0.2 A (Current density j 48.78 A m⁻²) and 10 mL min⁻¹ with a removal efficiency of 68.69%, and after 160 min, the removal increased to 99.56%. AlMg/AlMg needs 10 min to achieve a concentration of 0.75 mg L⁻¹ F⁻ at 0.2 A (j 25 A m⁻²), 16 mL min⁻¹ with a removal efficiency of 67.39%, and after 100 min, the removal is increased to 92.17%. An important and novel advantage is the use of AlMg allows an acceptable removal of F⁻ (<1.5 mg L⁻¹) at high and low concentrations in short periods of time; this also allows save energy costs and the effluent is free of residual aluminum, avoiding side effects.

摘要

本研究的目标是在连续流动中应用电凝工艺对饮用水进行脱氟。研究了两个采样点，墨西哥州 Temascalcingo (T) 和瓜纳华托州 Jerecuaro (J)，氟化物 (F ^- ) 浓度高于标准（分别为 2.3 mg L ^-1和 4.5 mg L ^-1）。此外，将第二个 Temascalcingo 样品富集 (T _E ) 至 9.2 mg L ^-1 F ^-以研究 F ^-专注。通过 Box-Behnken 模型提出了响应面设计，研究的变量为电极系统、流速和电流强度。使用 T-site 进行了 51 次实验，以确定系统的最佳运行条件。这些条件适用于 J 位点。T、Al/Al 系统的实验在处理 10 分钟、0.2 A（电流密度j 48.78 A m ^-2）和 10 mL min ^-1时达到了允许范围内的 F ^{-浓度（0.72 mg L -1} F ^- ）去除效率为68.69%，160 min后去除率提高到99.56%。AlMg/AlMg 需要 10 分钟才能达到 0.75 mg L ^-1 F的浓度⁻在0.2 A ( j 25 A m ^-2 )、16 mL min ^-1下，去除效率为67.39%，100 min后去除率提高到92.17%。一个重要且新颖的优点是使用 AlMg 可以在短时间内在高浓度和低浓度下可接受地去除 F ^- (<1.5 mg L ^{-1 )；}这也可以节省能源成本，并且出水不含残留铝，避免了副作用。