The rotating-biological-contactor (RBC) and the activated-sludge (AS) technologies, applied to town sewage treatment are compared on an economical basis, in the Italian market context. Two treatment schemes are considered: oxidation-nitrification (ON) and oxidation-nitrification-denitrification (OND). Anaerobic digestion of biomass wastage sludge is also accounted for in connection with a cogeneration plant utilizing the bhiogas thereby produced. The obtained results show that AS plants are generally less onerous than RBC plants whenever denitrification is needed, while RBC plants are preferable to AS ones when a simple oxidation-nitrification treatment is performed on comparatively small scale plants (< 25,000 equivalent inhabitants). The total cost difference between AS and RBC plants is though limited: lower than 7% for the ON process and lower than 17% for the OND one. Therefore, except for large-scale OND plants for which the AS technology appears to be fairly convenient, additional technical aspects and local constraints should be considered together with economical issues for a proper choice. An improvement in the reliability of RBC rotors and a higher degree of competition among producers are needed in order to reduce the comparatively high investment costs typical of this technology which, on the other hand, allows much louver energy consumptions and running costs than those of the AS technology
Sewage treatment plants: economical comparison between activated-sludge and rotating-biological-contactor technologies / Saracco, Guido; Specchia, Vito. - In: CHEMICAL AND BIOCHEMICAL ENGINEERING QUARTERLY. - ISSN 0352-9568. - 9:1(1995), pp. 7-17.
Sewage treatment plants: economical comparison between activated-sludge and rotating-biological-contactor technologies
SARACCO, GUIDO;SPECCHIA, Vito
1995
Abstract
The rotating-biological-contactor (RBC) and the activated-sludge (AS) technologies, applied to town sewage treatment are compared on an economical basis, in the Italian market context. Two treatment schemes are considered: oxidation-nitrification (ON) and oxidation-nitrification-denitrification (OND). Anaerobic digestion of biomass wastage sludge is also accounted for in connection with a cogeneration plant utilizing the bhiogas thereby produced. The obtained results show that AS plants are generally less onerous than RBC plants whenever denitrification is needed, while RBC plants are preferable to AS ones when a simple oxidation-nitrification treatment is performed on comparatively small scale plants (< 25,000 equivalent inhabitants). The total cost difference between AS and RBC plants is though limited: lower than 7% for the ON process and lower than 17% for the OND one. Therefore, except for large-scale OND plants for which the AS technology appears to be fairly convenient, additional technical aspects and local constraints should be considered together with economical issues for a proper choice. An improvement in the reliability of RBC rotors and a higher degree of competition among producers are needed in order to reduce the comparatively high investment costs typical of this technology which, on the other hand, allows much louver energy consumptions and running costs than those of the AS technologyPubblicazioni consigliate
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https://hdl.handle.net/11583/1653987
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