高氟高氯酸性废水处理实验研究

Removal of F^- and Cl^- from acid sastewater containing high concentration of fluoride ion and chloride ion

以有色金属冶炼行业产生的含高浓度氟、氯离子的酸性废水为处理研究对象,采取先除氟后除氯的思路,实验研究了使用氢氧化钙和偏铝酸钠去除废水中氟离子和氯离子的处理工艺.正交实验和单因素实验结果表明:影响氟离子去除效果的因素先后顺序为:钙氟比>p H>反应时间>沉降时间>PAM;影响氯离子去除效果的因素先后顺序为:钙氯比>铝氯比>反应温度>反应时间>p H.除氟阶段控制钙氟摩尔比为1.5∶2、废水p H值为12、搅拌反应时间40 min、PAM投加量3 mg/L、沉降75 min,废水中氟离子浓度可以由6300 mg/L下降到19.3 mg/L,去除率达到99.6%.除氯阶段按Ca(OH)2∶Na Al O2∶Cl-为10∶4∶1投加,12<p H<13,控制温度25℃,反应时间60 min,废水中氯离子浓度从1078 mg/L下降到280 mg/L以下,去除率达到74.02%.

Metal smelting process produces a great deal of of F- and Cl- . The treatment effect of treating fluorine hydroxide and sodium aluminate is studied. The orthogonal acid wastewater, which contains high concentration ion and chloride ion in wastewater with calcium experiments show that the factors which affect the effects of removing fluorine ion and chloride ion order respectively as： the mole ratio of calcium and fluoride〉 pH 〉reaction time 〉 the quantity of PAM; the mole ratio of calcium and aluminum and chloride 〉pH 〉 temperature〉reaction time. The effluent concentration of F- is reduced from 6300 mg/L to less than 19.3 mg/L when the mole ratio of calcium and fluoride is 1.5：2, wastewater pH is 12, reaction time is 40 min, PAM dosage is 3 mg/L and precipitation time is 75 min, and the removal rate can reach 99.6 %. The effluent concentration of C1- is reduced from 1028 mg/L to less than 280 mg/L when the mole ratio of calcium and aluminum and chloride is 10：4：1, 12〈pH〈13, reaction temperature is 25 ℃ and reaction time is 60 min, the removal rate can reach 74.02 %.