Application of bioaugmentation in the rapid start-up and stable operation of biological processes for municipal wastewater treatment at low temperatures

To accelerate the start-up of biological municipal wastewater treatment processes at low temperatures and ensure their daily stable performances, bioaugmentation was adopted with the addition of specialized mixed bacteria. As a result, three types of biological processes were successfully started within 15 days and showed stable and efficient daily performances. Results of PCR–DGGE analysis demonstrated the long-term predominance of the bioaugmented specialized bacteria in the bioaugmented systems. And results of BIOLOG analysis showed that the bacterial community structure and catabolic capability of the biological systems varied with wastewater temperature variations. However, the stability of the bacterial community under normal operating conditions and adaptability to perturbations enabled the long-term stable and efficient performances of the biological systems. In conclusion, bioaugmentation was successful for rapid start-up and stable performances of three typical biological municipal wastewater treatment processes at low temperatures.