除氟剂NY⁃Z02在高盐含氟废水中除氟应用研究

Removal of Fluoride from High⁃Salt Fluoride⁃Containing Wastewater Using Defluorination Agent NY⁃Z02

针对废旧电池回收过程产生的高盐含氟废水,采用高效除氟剂(NY⁃Z02)除氟,考察了反应终点pH值、反应温度、反应时间、除氟剂用量对除氟效果的影响,在此基础上提出了两段除氟工艺,并进行了中试试验。结果表明,在反应终点pH=7.0、反应温度20℃、反应时间20 min条件下,采用单段除氟工艺、除氟剂用量1.2%时废水中氟浓度降至12.5 mg/L,采用两段除氟工艺、除氟剂用量1.0%时,废水中氟浓度降至12.4 mg/L;中试试验除氟剂用量减少至0.768%,除氟后废水中氟浓度满足企业要求(不高于20 mg/L)。采用NY⁃Z02进行废水除氟,氟离子与除氟剂形成沉淀物(AlF 3)或随除氟剂生成的Al(OH)3絮凝沉淀得以去除,除氟效果好,且不引入杂质。

An efficient defluorination agent(NY⁃Z02)was used to remove fluoride from high⁃salt fluoride⁃containing wastewater generated in the process of recycling spent batteries.The effects of pH value,reaction temperature,reaction time and dosage of defluorination agent on fluoride removal effect were investigated.On this basis,a two⁃stage fluoride removal process was put forward,with which a pilot test was carried out.Results show that by using a single⁃stage fluoride removal process,a reaction runs at 20℃for 20 min with pH of 7.0 at the end and by adding defluorination agent at an amount of 1.2%,resulting in the fluoride concentration in the wastewater decreased to 12.5 mg/L.While by using a two⁃stage fluoride removal process,with addition of defluorination agent at an amount of 1.0%,the fluoride concentration in the wastewater can be decreased to 12.4 mg/L.In the pilot test with the dosage of defluorination agent reduced to 0.768%,the fluoride concentration in the wastewater after fluoride removal process met the requirement of enterprise(F≤20 mg/L).It is found that during the removal process with agent NY⁃Z02,fluoride ions in wastewater react with the agent and form precipitate of AlF 3,or together with Al(OH)3 are removed by flocculation and precipitation.It is shown that this process has good fluoride removal effect without bringing in any impurities.