Degradation of organic compounds in coal coking wastewater treated by the A1-A2-O biofilm system
焦化废水中有机物在A1-A2-O生物膜系统中的降解机理研究

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.