高含油煤气化废水除油预处理的工艺研究

Oil removal pretreatment process of high oil-containing coal gasification wastewater

对高含油煤气化废水的预处理工艺包括酸析、强化混凝、络合萃取技术及相互组合工艺等进行了研究。结果表明,酸析-混凝工艺对原水进行处理的最佳条件为:p H为4.50,聚合氯化铝(PAC)和阴离子聚丙烯酰胺(PAM)的质量浓度分别为3 000 mg/L和2.0 mg/L,处理后,CODCr和油类的去除效率分别为11.9%和19.0%。酸析-络合萃取-强化混凝组合实验最优条件为:p H为4.07,有机相和水相的体积比(O/A)为1∶1,萃取温度为20℃,强化混凝PAC质量浓度为1 500 mg/L。经酸析-络合萃取-强化混凝组合工艺处理后,CODCr和含油量分别降至4 277 mg/L和44 mg/L,去除率分别达到88.14%和97.57%。酸析-络合萃取-强化混凝组合工艺是一种有效的煤气化废水预处理技术,既回收了资源,同时也有利于进一步的生物氧化工艺处理。

The pretreatment processes for oil-containing coal gasification wastewater are studied,including acid precipitation,coagulation,coordination extraction and the coupled technologies. For the effluent treated by coupled acid precipitation-coagulation process,the CODCrremoval rate and oil removal rate are 11. 9% and 19. 0%,respectively,with4. 50 of p H,3000 mg / L of polyaluminium chloride and 2. 0 mg / L of anionic flocculant（ PAM）. In comparison,the integrated acid precipitation-coagulation-coordination extraction process has better CODCrremoval rate and oil removal rate（ 88. 14% and 97. 57%,respectively） under the following conditions： 4. 07 of p H,1 ∶ 1 of O / A rate,20℃ of the extraction temperature and 1 500 mg / L of PAC. It suggests that the integrated acid precipitation-coagulation-coordination extraction process is an efficient technology to pretreat the high oil-containing coal gasification wastewater,which both recycles the resources and is helpful to the further biological oxidation.