Treatment of slightly polluted wastewater in an oil refinery using a biological aerated filter process

Wuhan University Journal of Natural Sciences 11/2007; 12(6):1094-1098. DOI: 10.1007/s11859-007-0080-2

ABSTRACT The slightly polluted wastewater from oil refinery contains some COD, oil pollutants and suspended solids (SS). A small-scale
fixed film biological aerated filter (BAF) process was used to treat the wastewater. The influences of hydraulic retention
time (HRT), air/water volume flow ratio and backwashing cycle on treatment efficiencies were investigated. The wastewater
was treated by the BAF process under optimal conditions: the HRT of 1.0 h, the air/water volume flow ratio of about 5:1 and
the backwashing cycle of every 4–7 days. The results showed that the average removal efficiency of COD, oil pollutants and
SS was 84.5%, 94.0% and 83.4%, respectively. And the average effluent concentration of COD, oil pollutants and SS was 12.5,
0.27, 14.5 mg·L−1, respectively. The experimental results demonstrated that the BAF process is a suitable and highly efficient method to treat
the wastewater.

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