焦化废水中有机物在A_1-A_2-O生物膜系统中的降解机理研究

Degradation of organic compounds in coal coking wastewater treated by the A_1-A_2-O biofilm system

对焦化废水中有机物在A1 A2 O生物膜系统各段的降解进行了研究 .结果表明 ,废水中主要有机组份为苯酚类和含氮杂环类化合物 ,它们所占比例分别为 5 0 %和 4 0 % .经过厌氧酸化处理后 ,苯酚类中简单酚得到了较大程度的降解 ,随着苯酚甲基取代基数目的增加 ,降解率逐渐降低 ,对三甲酚则没有降解 ;简单的含氮杂环化合物如喹啉、异喹啉、吲哚、吡啶在厌氧过程中也得到了较大的降解 ,而有取代基的含氮杂环化合物则有所增加 ;喹啉和甲基喹啉的降解可生成羟基喹啉和甲基 2(1H)喹啉酮中间产物 .经过厌氧酸化段处理后 ,废水的BOD5 COD有较大提高 .厌氧出水的大部分有机物可在缺氧段得到降解 .最终出水中有机物基本上为大分子难降解物质 .

Degradation of organic compounds in coal coking plant wastewater treated by the anaerobic acidification-anoxic-aerobic (A_1-A_2-O) biofilm system was studied. The results showed that the main organic compounds in the coal coking wastewater are phenol or its derivatives, and nitrogen heterocyclic compounds. They take 50% and 40% of the total organic compounds in the wastewater respectively. After treated by anaerobic unit, phenol was degraded significantly. The degradation efficiency decreased when the numbers of substituent methyl group on phenol increase. Trimethyl phenol could hardly be degraded in the anaerobic unit. Some simple nitrogen heterocyclic compounds such as quinoline, isoquinoline, indole, pyridine were also largely degraqded in the anaerobic unit, but substitution derivatives of nitrogen heterocyclic compounds increased. Oxyquinoline and methyl-2(1H)-quinolinone were the intermediate degradation products of quinoline and methyl quinoline respectively. BOD-5/COD of the wastewater increased greatly after treated by the anaerobic acidification unit, and most organic compounds in anaerobic effluent can be degraded in the anoxic unit. The organic components in effluent of the aerobic unit were mainly biorefractory compounds with big molecule.