Use of an industrial effluent as a carbon source for denitrification of a high-strength wastewater

Abstract

Denitrification of a high-strength synthetic wastewater (150 g NO^- ₃ l^-1) was carried out using a wine distillery effluent as an example of an industrial carbon source (22.7 g chemical oxygen demand l^-1). Two configurations were tested: one consisted of an acidogenesis reactor followed by a denitrifying reactor and the other was a single reactor directly fed with the raw effluents. In both cases, denitrification was achieved at a nitrate load of 9.54 g NO^- ₃ l^-1 day^-1 (2.19 g N as NO^- ₃ l^-1 day^-1) with good specific reduction rates: 32.6 mg and 35.2 mg N as NO _x  g volatile suspended solids h^-1, calculated on a single day, for the two-step and the one-step process respectively. Dissimilatory nitrate reduction to ammonium did not occur, even in the one-step process.