Study Of EGSB Reactor Removing Volatile Phenol Of Coking Wastewater Under Micro-Aerobic Conditions

Along with the rapid development of industrial, coking wastewater increases in quantity, Phenols of coking wastewater are hazardous materials, which make the water conditions polluted badly, the treatment of phenols has become the issues that must be resolved. In this investigation, EGSB reactors are utilized to treat coking wastewater, The phenol removal efficiency of reactor and influencing Factors of the operation of reactor are analysed under continuous micro-aerobic conditions in this paper.Three EGSB reactors were used to treat coking wastewater in this investigation. By using anaerobic and intermittent micro-aerobic conditions as a reference, EGSB reactor that remove volatile phenol of coking wastewater are analyzed under continuous micro-aerobic conditions. Experiment results showed that:During the operation of reactor, the quality of coking wastewater has influenced the operation of reactor. The results show that reactor have very strong ability of resisting loads shock under continuous micro-aerobic conditions, the reactor have good phenol removal efficiency. At the time of 87d, With influent phenol concentration of 154.34～201.34mg/L and COD concentration of 1761～1927mg/L, the phenol removal efficiency of the reactor under anaerobic and intermittent micro-aerobic conditions decreased from 53% and 63% to 27% and 38% respectively, but the reactor could attain 100% phenol removal efficiency under continuous microaerobic conditions. However, after temperature decreased, At the time of 136d, Because of the weather condition, the temperature of outdoor and reactor decreased to -19℃and 24～25℃respectively. The performance of three EGSB reactors has decreased obviously. The phenol removal efficiency of reactors under anaerobic, intermittent and continuous micro-aerobic conditions decreased from 25%, 99%,95% to 16%,27%,15% respectively. Then we took measures immediately to resume the reactor temperature to 30-33℃. The removal efficiency of continuous micro-aerobic reactor have resumed only in 11 days, but anaerobic and intermittent micro-aerobic reactors are very difficult. Supplement of appropriate oxygen is benefit to the stable operation of EGSB reactor, and can make oxidation reaction among metabolic intermediates. Methanogenic bacteria that exist in granules are not sensitive to the low oxygen level, because of the Metabolic synergy in granules, some refractory and toxic compounds are transferred and degraded timely. The granular sludge have an enrichment micro-community, from the exterior to interior of granular sludge, there are aerobic bacteria, facultative bacteria and anaerobic bacteria, gradually.