Yuriy I. Pankivskyi (2000). COMBINED PHYSICAL-CHEMICAL AND BIOLOGICAL TREATMENT OF MUNICIPAL WASTEWATER UNDER COLD WEATHER CONDITIONS, ME Thesis, Lenox Institute of Water Technology, USA; May 2000, 67 p. In: “Environmental Science, Technology, Engineering, and Mathematics (STEM)” , Lawrence K Wang., Mu-Hao Sung Wang, and Nazih K. Shammas (editors). Volume 2000, Number 5, May 2000; 67 p. Lenox Institute Press, Newtonville, NY, USA. …..ABSTRACT: Innovative Combined Physical-Chemical and Biological process system has been elaborated and proposed as an alternative technology for municipal wastewater treatment plants operation. In the series of laboratory bench-scale experiments typical raw municipal wastewater from the Town of Lee, Massachusetts, USA, was treated directly, or elevated to design concentrations ( BOD5 / TSS / NH3-N = 250 mg/L / 250 mg/L / 25 mg/L) before treatment. The current and future National Pollutant Discharge Elimination System (NPDES) effluent limitations were the goals for wastewater treatment in this research. Innovative Dissolved Air Flotation (DAF) Technology was applied for primary and secondary clarification. Improved activated sludge single-sludge process was applied for biological treatment (carbonaceous oxidation, nitrification and denitrification) under simulated cold weather conditions. Three complex experiments were performed to prove the system efficiency. It is concluded that the combination of primary DAF, aerobic carbonaceous oxidation, aerobic nitrification, anoxic denitrification, secondary DAF-Filtration and chlorination is an effective innovative system for municipal wastewater treatment. The future NPDES effluent standards can be met. Addition of RAS from a stabilization tank will increase the efficiency of biological treatment.