DTRO膜和NF膜处理污酸废水研究

针对某冶炼厂污酸废水的水质特点,提出"预处理+膜处理"的工艺路线.重点研究了废水pH值对CO2除钙的影响、铝盐药剂种类和反应pH值对除砷、氟的影响,最后分别采用DTRO膜和NF膜对预处理后的废水进行分盐浓缩.试验结果表明:当废水pH值为9.0时,废水中ρ(Ca)最低为1.0 mg/L.当铝盐与氟砷摩尔比为1.3:1.0,反应pH值为6.0时,砷和氟的去除率分别为59.3%和88.0%.在7.5 MPa压力下,DTRO膜产水率高达88%,对各种盐分截留率均大于94.5%.而NF膜在4.0 MPa压力下,硫酸根离子和氯离子的分盐率在99%以上.

Study on sewage acid wastewater treatment with DTRO/NF membrane

Based on water quality characteristics of sewage acid wastewater treatment in a smelter,pretreatment plus membrane treatment routing was proposed.Effect of pH value on calcium removal of CO2,agent type of aluminum salt and reaction pH value on removal of arsenic and fluorine were mainly studied.DTRO membrane and NF membrane were used to separate salt and concentrate pretreated wastewater respectively.The results showed that when pH value was 9.0,the lowest concentration of calcium ions in solution was 1.0 mg/L.When the molar ratio of Al/(F+As)was 1.3∶1.0 and reaction pH value was 6.0,the removal rates of arsenic and fluorine were 59.3%and 88.0%.At the pressure of 7.5 MPa,water production rate of DTRO membrane was 88%,and the salt rejection of all kinds salts were more than 94.5%.On the other side,the separation rate of SO42-and Cl-in NF membrane was more than 99%at the pressure of 4.0 MPa.