4. Conclusion
The GPDBD is an effective method for the removal of organic
pollutants from coking wastewater and forms an applicable pretreatment
step. The result shows that at an initial pH of about
8.5, air flow rate of 2 L min1
, COD removal efficiency reached
70%, NH3–N removal efficiency was 21% and approximately 100%
of total phenol was removed at a reaction time of 120 min. Several
PAHs compounds, including benzoquinone, naphthalenol and
dimethyl phthalate were removed completely as determined by
GC–MS analysis. After a reaction time of 100 min, the rate of
BOD5/COD from 0.14 to 0.52, indicating the biodegradability of
coking wastewater significantly improved