萃取皂化废水除COD制工业盐工艺研究

Study on Technology of Preparing Industrial Salt by Removing COD from Extraction Saponification Wastewater

研究了皂化废水中含油量、COD浓度对皂化废水结晶盐的品质影响和Fenton氧化法降解COD工艺。结果表明,经活性炭除油后,含油量小于5mg/L;在摩尔比n(H2O2)/n(Fe2+)=8、反应pH=3.0、双氧水浓度0.0472mol/L、反应时间60min的条件下,COD浓度小于217mg/L。经上述工艺处理后的皂化水用氢氧化钠沉淀除铁,蒸发结晶可以得到白度为87.52、氯化钠纯度为95.7%,达到一级标准的工业级氯化钠盐。

Effects of oil content and COD concentration in saponification wastewater on quality of saponification wastewater crystal salt and Fenton oxidation degradation process of COD were studied.The results show that oil content is less than 5 mg/L after degreasing by activated carbon.COD concentration is less than 217 mg/L under the conditions including mole ratio of n(H2O2)/n(Fe2+)=8,reaction pH value of 3.0,reaction time of 60 min,and hydrogen peroxide concentration of 0.0472 mol/L.Saponified water treated by the above process is precipitated with sodium hydroxide to remove iron,and evaporative crystallization can obtain industrial-grade sodium chloride salt with whiteness of 87.52,purity of sodium chloride of 95.7%,and reaches first-class standard.