聚乙烯醇在超临界水氧化中降解

以H2O2为氧化剂用间歇式超临界水氧化装置对聚乙烯醇(PVA)废水进行降解研究。通过正交实验,考察了反应温度、压力、时间及氧化剂过氧倍数对降解效果的影响,并且采用GC/MS对液相降解产物进行表征推测其可能降解途径。结果表明:PVA在SCWO体系中能完全降解,反应温度440℃、压力28 MPa、氧化剂过氧倍数4、反应40 min时,COD去除率为99.03%,出水COD=89.09 mg/L。PVA在SCWO体系中降解为烯烃、烯酮、醇和羧酸类中间产物、最终降解为小分子的饱和直链烷烃类液相产物。

Degradation of PVA by supercritical water oxidation

The degradation of polyvinyl alcohol(PVA)using H2O2 as the oxidant in a batch tube reactor was studied.The influences of temperature,pressure,time and excess oxygen on the COD removal rate were investigated and the process conditions were optimized through orthogonal tests.The chief liquid products were characterized by GC/MS.The results showed that PVA could be degraded completely in supercritical water.When the reaction temperature was 440℃,the pressure was 28 MPa,oxygen excess was 4,and the reaction time was 40 min,the COD removal rate could achieve 99.03% and COD of the effluent was 89.09 mg/L.The liquid products were alkene,enol,mellow,organic acids,straight chain alkane,and so on.