摘要
针对传统化学沉淀法处理含氟废水工艺中存在的氟资源浪费和污泥堆存困难的问题,提出了以氢氧化钙悬浊液为沉淀剂,流化床结晶法脱氟的新工艺.在小试规模下,采用流化床反应器对15L/h的含氟废水进行了处理,考察了反应时间、钙氟摩尔比、回流流量、钙液组成等因素对脱氟效果的影响.结果表明,进水氟浓度为1000mg/L、钙氟摩尔比=0.6、钙液中氯化钙与总钙的摩尔比=0.10时,出水氟离子浓度稳定低于20mg/L.在中试规模下,以某氟化盐厂工业废水为对象,采用流化床结晶—絮凝的组合工艺对0.5m3/h的废水进行了处理,出水氟离子浓度低于10mg/L,达到污水综合排放一级标准,氟化钙污泥含水率为27.0%、平均粒径为159.0μm,易于固液分离和回收利用.
Against the problems of fluoride wasting and sludge piling in the traditional chemical precipitation process, a novel fluidized bed crystallization process was proposed to remove fluoride in the fluorine-containing wastewater, in which the supernatant of calcium hydroxide was used as precipitant. The fluorine-containing wastewater of 15L/h was treated by a laboratory fluidized bed reactor. The effects of operating time, molar ratio n （Ca）：n （F）, reflux flow, and precipitant composition on defluorination efficiency were investigated. The results showed that the fluoride concentration of effluent was less than 20mg/L when n （Ca） ： n （F） = 0. 6, the content of CaC12 in the precipitant was 10%, and imquent concentration of fluoride was 1000mg/L. The industrial wastewater of O. 5m3/h in a fluoride factory was treated by pilot-scale fluidized bed crystanization-flocculation process. The fluoride concentration of effluent was less than 10mg/L and met the primary requirements of Integrated Wastewater Discharge Standard. The moisture content of CaF2 sludge in the bottom fluidized bed was 27.0% and the mean particle size was 159.0μm. The product could be separated and reused easily.
出处
《应用基础与工程科学学报》
EI
CSCD
北大核心
2012年第6期1032-1041,共10页
Journal of Basic Science and Engineering
基金
湖南省科技重大专项:湘乡工业区钢铝冶金重要辅助原料生产节能减排技术开发与示范(子项目:含氟废水深度净化及氟石膏资源化)(2009FJ1009)
关键词
含氟废水
流化床
氟化钙
结晶法
Fluorine-containing wastewater
fluidized bed
calcium fluoride
crysl^allization
