Abstract: The wastewater from coal to ethylene glycol is a typical coal chemical wastewater, which is difficult to be treated stably by conventional biochemical treatment and has high operation cost. The A/O fluidized bed biofilm reactor has the characteristics of high microbial concentration, high volume load and sludge load, fast mass transfer, strong impact load resistance and good treatment effect. The A/O fluidized bed biofilm reactor developed by SINOPEC(named A/O SFBBR) was used to treat glycol wastewater. The treating effects of operating conditions, such as C/N, HRT and nitrate liquid reflux ratio, were investigated. The economic technique analysis for SFBBR and traditional A/O reactor were compared. The results showed that: (1) the performance of SFBBR was best when the C/N was in the range of 3.5 to 5.0, the hydraulic retention time (HRT) of aerobic reactor was in the range of 10 to 21h and the nitrate reflux ratio was in the range of 1.5 to 4.5; and the average COD, NH4--N and TN concentration of the effluent were 18.3 mg/L, 4.7 mg/L and 19.3 mg/L, respectively; (2) compared with the traditional A/O reactor, the SFBBR exhaust gas emission reduced by about 80%, waste produced sludge reduced by about 43%, the project investment decreased by about 16%, and the operating cost reduced by 30% approximately.

Key words: anoxic/oxic fluidized bed biofilm reactor, coal to EG wastewater, operation effect