电絮凝-气浮-砂滤组合工艺除氟

Removal of fluoride by combined technology of electrocoagulation-flotation-filtration

为了有效去除水中的氟离子,对电絮凝-气浮-砂滤组合工艺除氟(F-)离子进行了研究。详细考察了电压、电絮凝停留时间和初始F-离子浓度等参数对除F-离子效率的影响。结果表明:当初始F-离子浓度为1.50 mg/L,停留时间为10 min,电压为15 V条件下,出水F-离子浓度为0.92 mg/L;当初始F-离子浓度为2.5 mg/L,停留时间为15 min,电压15 V条件下,出水F-离子浓度为0.98 mg/L。用Al-Ferron逐时络合比色法表征了电絮凝和气浮单元出水中铝形态随时间的变化。结果显示:电絮凝出水Ala含量随时间增加迅速降低到5%以下,电絮凝和气浮单元出水Alb含量均占到50%以上,Alc含量均随时间增加而增加。

This paper investigated the removal of fluoride from aqueous solution using the combined technology of electrocoagulation-flotation-filtration.Effects of the voltage,hydraulic retention time（HRT） and initial fluoride concentration on the efficiency of fluoride removal were systematically evaluated.Results showed that the fluoride concentration was reduced to 0.92 mg/L with the initial fluoride concentration of 1.5 mg/L,HRT of 10 min and voltage of 15 V;the fluoride concentration was reduced to 0.98 mg/L with the initial fluoride concentration of 2.5 mg/L,HRT of 15 min and voltage of 15 V.The change of aluminum species in the effluent with time was characterized by Al-Ferron timed complex-colorimetric method.The result indicated that the content of Ala in the effluent of electrocoagulation unit rapidly decreased below 5% with the increase of time;the content of Alb in the effluent of both electrocoagulation and floatation units was above 50%;the content of Alc in the effluent of both units increased with time.