1. Technical and economic analysis of real anaerobic digester centrate by means of partial nitrification and sustainable heterotrophic denitrification.
- Author
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Bartrolí, A., Garcia-Belinchón, C., Hidalgo, J. M., Rougé, P., Fàbregas, C., Fortuny, M., Lafuente, J., and Prado, Ó. J.
- Subjects
SEWAGE disposal plants ,ANAEROBIC digestion ,SEQUENCING batch reactor process ,DENITRIFICATION ,NITRIFICATION ,SUSPENDED solids ,BIOCHEMICAL oxygen demand - Abstract
The reliability of partial nitrification coupled with heterotrophic denitrification for the treatment of real anaerobic digester centrate produced in a wastewater treatment plant was technically and economically assessed in two sequencing batch reactors. Removal efficiencies above 90% were consistently achieved at N-ammonium loads above 1.2 g N L
-1 d-1 . Ethanol, affluent from a waste water treatment plant (biological treatment inlet) and a zero-cost liquid residue from a chemical industry containing polyethylene glycol and sorbitol were employed as carbon source for denitrification. In this last case, a total organic carbon (TOC) requirement of 4.5 g TOC g-1 NO2 - -N was calculated. The denitrification rate was 0.26 g NO2 - -N g VSS-1 d-1 (VSS: volatile suspended solids). These results show that a carbon-rich waste can serve as a no-cost feed for denitrifying bioreactors. An in-depth economic analysis considering the main investment and operating costs of the process was developed, showing that it can suppose yearly savings above 50% with respect to the most widely used alternative of returning anaerobic digester centrate untreated to the head of the facility. [ABSTRACT FROM AUTHOR]- Published
- 2013
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