采用疏水改性纤维膜处理热镀锌废酸液实验研究

以高孔隙率的纤维膜为气液屏障,研究采用纤维膜的膜蒸馏技术在处理热镀锌废酸液过程中的可行性与效果。结果表明,疏水改性纤维膜对废酸液中含有的Fe^2+的截留率大于99.9%,且废酸液温度越高,渗透通量越大,最大渗透通量约为3.2 kg/(m^2·h)。膜蒸馏过程中,废酸液中的HCl挥发为气体穿过纤维膜,在冷凝侧冷凝为稀盐酸。废酸中的FeCl2会提高HCl蒸气分压力,使HCl的渗透通量增大,总渗透通量减小,从而使蒸馏液中HCl含量增大,有利于回收HCl。将疏水改性纤维膜应用于膜蒸馏过程处理热镀锌废酸液是可行的。

Experimental Study on the Treatment of Galvanizing Waste Acid by the Hydrophobic Modified Fibrous Membranes

The high porosity fibrous membrane was used as a gas-liquid barrier,and the feasibility and performance of membrane distillation using fibrous membrane in the treatment of the waste acid solution from the galvanizing industry were studied.The results showed that,the rejection rate of Fe2+contained in the waste acid solution was higher than 99.9%,and the higher temperature of the waste acid solution,the bigger the permeation flux,the maximum permeation flux was about 3.2 kg/(m2·h).During the membrane distillation process,the HCl in the waste acid was volatilized as a gas passing through the fiber membrane and condensed into dilute hydrochloric acid on the condensation side.The present of FeCl2 in the waste acid solution increased the partial pressure of HCl,which increased the permeate flux of HCl and decreased the total permeation flux.Therefore,the HCl content in the distillate increased,which was beneficial to recover HCl acid.It is feasible to apply the hydrophobic modified fiber membrane to the membrane distillation process for the waste acid of hot-dip galvanizing treatment.