内循环流化床吸附-膜分离工艺的饮水除氟特性

将内循环吸附与膜分离技术联合，开发一种新型饮水除氟工艺。为明确工艺特性，以模拟高氟水为实验原水，采用连续流小试装置，通过单因素实验和响应面法分析了HRT、吸附剂投加量2个重要参数对工艺除氟效能的影响规律。结果表明，HRT与活性Al2O3投加量对工艺的除氟效能均存在显著影响，在一定条件下存在最优值。响应面分析结果表明，最佳条件为：HRT=3.2 h，活性Al2O3投加量为5 g·L-1。该条件下，出水氟浓度最低可降至0.2 mg·L-1，在瞬时出水氟浓度与累积出水平均氟浓度超标前，单位活性Al2O3的处理水量分别为1.15 t·kg-1和1.36 t·kg-1；工艺运行过程中，TMP处于较低水平且增加缓慢，表明膜污染程度较小；基于吸附原理与物料平衡原理建立了工艺连续流动态数学模型，模拟得出的出水氟浓度动态变化曲线与实测结果较为一致。

Fluoride removal from drinking water by the process combined internal circulating fluidized bed and membrane

A new method of fluoride removal was developed by adding a membrane into a pneumatic internal circulating fluid-bed adsorption reactor. The HRT and adsorbent dosage are the two most important parameters for this process. Their influences on the fluoride removal were studied by a series of single-factor tests and the response surface method (RSM) with a pilot test device. The results indicate that both factors have a marked influence on the fluoride removal, and can be optimized. The optimum values of the HRT and the dosage of Al2O3 in this study were 3.2 h and 5 g·L-1, respectively. Under these conditions, the lowest concentration of F- in the effluent was 0.2 mg·L-1; 1 kg of activated Al2O3 could treat an average of 1.15 t and 1.36 t water for the instantaneous F- of effluent and the average F- of cumulative treated water, respectively. During device operation, the low level of TMP suggested that minor membrane fouling had occurred. The model developed to predict the time variation of F- in the effluent was based on the theoretical adsorption and material balance equation, where the predicted dynamic curve of F- in the effluent was identical to that of the measured curve.