Photosynthetic bacteria (PSB) can assist with wastewater purification and useful biomass recovery
without excess sludge. The feasibility of using PSB to treat white spirit wastewater was studied. The
effects of the crucial process factors were also tested. The results demonstrated that using PSB to treat
white spirit wastewater was feasible, and biomass production was achieved. PSB exhibited the ability to
acclimatize to white spirit wastewater: they were tolerant of a high COD of 9100e25,600 mg l1 and an
ethanol concentration of 0.5e2.0% (v/v). In addition, PSB were able to adapt to a pH of 5.0e8.0 and adjust
the effluent pH. These characteristics were favorable for white spirit wastewater treatment. In performance
improving study, dilution (reflux) was used as a strategy to improve the degradation effectiveness.
Refluxing with a ratio of 300% was the optimal method. A similar treatment effect as an anaerobic process was achieved: the COD removal reached 76.02%, and valuable biomass instead of excess sludge was simultaneously obtained.