Coking Waste Water Treatment Application And Research Of O-A-O-O Combinnation Process In Qian’an Zhonghua Company

In Qian’an Zhonghau Company,the COD concentration of surplus ammonia water is much higher than other coking enterprise because it is influenced of the level of coal blending and coke oven, chemical process, etc,. The COD concentration of steamed ammonia wastewater after steamed ammonia has reached scope of5000-6000mg/l.In this case, the original phenol cyanogen wastewater treatment plant processing capacity has not been able to need, because of COD concentration of the wastewater is high, the system sludge load is increased, resulting in the activated sludge flora appear serious imbalance, especially nitrifying bacteria can’t survive in high COD concentrations, therefore, the preoxidation process through the preliminary aeration for high concentration wastewater, create favorable conditions for nitrifying bacteria and denitrifying bacteria through reducing the COD load of subsequent biochemical process.This paper study on process modification for the coal wastewater in Qian’an Zhonghua company,On the basis of the original wastewater treatment process of A-O-O basically remain unchanged, a pre aeration pool is added at the front,After the site test in qian’an zhonghua company and simulation of the original process of all kinds of operation parameters, pre aeration pool is added in the A-O-O process, and through the pre aeration pool test research in air aeration state and dosing activated sludge state, we find the effect of dosing active sludge is superior to the effect of only aeration.Wastewater COD removal rate is from21.29%to50%above when the activated sludge be added in the pre aeration pool. At the same time,volatile phenol removal efficiency is from20%to90%, the cyanide removal efficiency is from32.99%to72.90%. Under the action of activated sludge in the pre aeration pool, the carbonation and ammoniation of the system are bringed forward, the nutrients structure of the water out the pre aeration pool are changed.especially the C/N ratio of water is changed, then, the follow-up process to transfer is beneficial to nitrification direction. In this case, the system’s nitrification significantly is enhanced, the ammonia nitrogen concentration in biochemical system drainage is reduced to the lowest standard,the situation that ammonia nitrogen emission concentration is higher is changed.At the same time, on the basis of field experiment, through the modification of the original system, the effluent COD index is decreased significantly, reached the ideal level, in this case, the system effluent ammonia nitrogen, volatile phenol, cyanide indexes all meet level1emission standard of the national discharge standards.Experiment research and industrial scale process reconstruction results show that the O-A-O-O combination process of this paper is suitable for the coking wastewater treatment under high COD concentration and is provided with promotion value in similar enterprises.