A full scale anaerobic–anoxic–aerobic process coupled with low-dose ozonation for performance improvement.

Highlights: [•] Low dose ozone was used and obvious effects were obtained in a full scale A/A/O process. [•] Large amount of carbon and little nutrient were solubilized. The ratios of carbon to nitrogen and carbon to phosphorus in ozonated sludge were much higher than influent. [•] Performance of A/A/O process was improved by low-dose ozonation. [•] Low-dose ozonation didn’t destroy sludge cell walls and had no effect on DO concentration of biological reactors. [Copyright &y& Elsevier]