Department of Chemical Engineering, College of Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Sakai-shi, Osaka 599-8531, Japan.
Water Res. 2010 Mar;44(6):1900-8. doi: 10.1016/j.watres.2009.11.023. Epub 2009 Nov 20.
We have studied the decomposition and decoloration of 4-(2-Hydroxynaphthylazo) benzenesulfonic acid sodium salt (AO7, acid dye) as a model for textile wastes by using a flow-type subcritical water system. The operating temperature was ranged from 180 to 374 degrees C at 10-25 MPa at a wide range of residence time. The pressure (up to 25 MPa) did not affect the decomposition reactions. AO7 completely decomposed at higher temperatures and or longer residence times. The main products from decomposition of AO7 were found to be 2-naphthalenol, phenol, 1,1'-Binaphthalene-2,2'-diol, and N-(phenylmethylene)benzenamine. In order to identify the decomposition pathways, the products were also individually treated under a batch type subcritical water conditions. We found that 2-naphthalenol underwent to further decomposition to 1,1'-Binaphthalene-2,2'-diol during the subcritical water reaction. Other decomposition products resulted from the decomposition of directly AO7. Kinetic model of the subcritical water reaction was developed by considering major products. The kinetic constants obtained from the proposed reaction pathway showed good agreement with experimental results.
我们使用流动型亚临界水体系研究了 4-(2-羟基萘基偶氮)苯磺酸钠盐（AO7，酸性染料）作为纺织废料模型的分解和脱色。操作温度范围为 180 至 374°C，压力为 10-25 MPa，停留时间范围很广。压力（高达 25 MPa）不会影响分解反应。在更高的温度和/或更长的停留时间下，AO7 完全分解。从 AO7 分解的主要产物被发现是 2-萘酚、苯酚、1,1'-联萘-2,2'-二醇和 N-(亚苯基亚甲基)苯甲胺。为了确定分解途径，还在分批式亚临界水条件下单独处理了产物。我们发现，2-萘酚在亚临界水反应中进一步分解为 1,1'-联萘-2,2'-二醇。其他分解产物是由直接的 AO7 分解产生的。通过考虑主要产物，建立了亚临界水反应的动力学模型。从提出的反应途径获得的动力学常数与实验结果吻合较好。
