Conventional water analysis based on influent sampling holds a limitation of accuracy due to fluctuation of influent composition in time. The study was aimed at identification of the composition from a back-calculation of biological responses in the activated sludge reactor. The developed approach was based on IWA ASM1, which was structured by the influent constituents. | Vietnam Journal of Science and Technology 55 (4C) (2017) 284-290 ESTIMATION OF BIODEGRADABLE MATERIAL CONCENTRATIONS IN THE SEWAGE USING IWA ACTIVATED SLUDGE MODEL Chanh Quang Nguyen Duong1, 2, *, Mitsuharu Terashima1, Hidenari Yasui1, Tuan Van Le3, Ha Thi Nguyen4, Chieu Van Le5 1 Graduate School of Environmental Engineering, the University of Kitakyushu, Kitakyushu,808-0135, Japan 2 Faculty of Environment, Danang University of Science and Technology, 54 Nguyen Luong Bang, Da Nang, Viet Nam 3 Department of Environmental Science, Hue University, 77 Nguyen Hue, Hue city, Viet Nam 4 Hanoi University of Science, Department of Environmental Technology Faculty of Environmental Science, 334 Nguyen Trai, Ha Noi, Viet Nam 5 Research Centre for Environmental Technology & Sustainable Development, 334 Nguyen Trai, Ha Noi, Viet Nam * Email: v4dac401@, m-terashima@, hidenariyasui@, lenntuan@, nguyenthiha@, lvchieu@ Received: 18 October 2017; Accepted for publication: 17 October 2017 ABSTRACT Conventional water analysis based on influent sampling holds a limitation of accuracy due to fluctuation of influent composition in time. The study was aimed at identification of the composition from a back-calculation of biological responses in the activated sludge reactor. The developed approach was based on IWA ASM1, which was structured by the influent constituents. A pilot-scale activated sludge 2 reactors (with and without primary settler were installed and operated continuously at Doan Thi Diem Str., Hue, Vietnam. Focusing on the activated sludge sampled from the reactor with a settler, the soluble biodegradable organic concentration in the influent was calculated. From the state variables in the activated sludge reactor, the organic matter and nitrogen compounds in the influent were calculated. Keywords: activated sludge reactor, back calculation, environmental modelling, influent constituents, .
