硝基T酸萃余硫酸溶液纳滤膜法净化技术

Purification of nitro T acid raffinate by nanofiltration membrane technology

H酸的中间体硝基T酸生产中产生大量废酸,通过叔胺类萃取剂N235处理该废酸,再采用纳滤膜脱除萃余液中残留萃取剂及可溶性萘系磺化物。适宜的纳滤前处理萃取条件：在萃取油相中不添加正辛醇;N235体积分数为33%,W/O（水油比）为2：1。经过二级萃取后,CODCr去除率为79%。二级萃余液采用纳滤膜浓缩至1/6体积,平均通量可达9.9~20.9 L·m-2·h-1,纳滤后可回收27%浓度的硫酸,CODCr总去除率为94%~97%,总色度去除率99%。大幅降低污染物排放量。

Production of nitro T acid which is an intermediate of H acid produces a large amount of waste acid.In this paper,the complex extraction coupled with nanofiltration membrane using trialkylamine（N235） as extracting agent was adopted to purify this waste acid in order to remove the residual extractant and soluble sulfonated naphthalene.The suitable extraction condition for nanofiltration processing was N235 volume fraction of 33%,water over oil ratio of 2：1 without addition of n-octanol.After secondary extraction,the removal rate of CODCrwas 79%.When the secondary raffinates were concentrated to one sixth of the volume by nanofiltration,the average fluxes of the membranes were 9.9—20.9 L·m-2·h-1.Sulfuric acid with 27% concentration（mass fraction） was recovered.The total removal rates of CODCr and chroma were 94%—97% and 99%,respectively.This coupling method could greatly reduce the pollutant emissions in production of nitro T acid.