臭氧催化氧化在石化废水深度处理应用中的若干问题

石化污水处理厂二级出水可生化性低,含部分有毒难降解有机物。随着GB 31571—2015《石油化学工业污染物排放标准》2015年7月1日的实施,我国石化污水处理厂迎来了一次集中处理技术升级,其大多采用以臭氧/臭氧催化氧化为核心的处理工艺建成深度处理单元,对石化污水处理厂二级出水进行深度处理使其达标排放。目前这类装置大多已运行超过2年,实际运行过程中,该技术出现了设计之初未曾考虑到的一系列问题,致使臭氧利用率不高且持续下降,治理成本逐年增高等。结合实际工程,从絮体、胶体大分子有机物、臭氧传质和催化剂4个方面对这些问题进行了系统分析,同时对臭氧催化氧化技术在石化污水处理厂二级出水处理中的发展方向进行了展望。

Application and problems of catalytic ozonation in advanced treatment of petrochemical wastewater

Biological effluent of petrochemical wastewater treatment plant contains toxic and refractory organic compounds, which is difficult to be furtherly treated by biological process. However, with the implementation of Emission Standard of Pollutants for Petroleum Chemistry Industry (GB 31571-2015) after July 1, 2015, the petrochemical wastewater treatment plants had experienced great centralized technology improvement. Meanwhile, most of the advanced treatment units have been built by ozone/catalytic ozonation process to achieve the discharge standard. At present, most of these advanced treatment units have been in operation for more than two years. With the actual operation, a series of problems which were not taken into account at the beginning of the design have arisen. Due to low ozone utilization rate and continuous deterioration, the treatment costs continuously increased. In order to solve these problems, combined with practical conditions, four aspects of the flocs, colloidal macromolecule organic compounds, ozone mass transfer and catalysts were analyzed. In the meantime, the development trend of ozone catalytic oxidation technology in secondary effluent treatment of petrochemical industry was put forward.