Abstract

TELLEZ-PEREZ, S.K.; SILVA, C.D.  and  TEXIER, A.C.. Simultaneous ammonium and p-hydroxybenzaldehyde oxidation in a sequencing batch reactor. Rev. Mex. Ing. Quím [online]. 2013, vol.12, n.1, pp.97-104. ISSN 1665-2738.

The simultaneous ammonium and p-hydroxybenzaldehyde (pOHBD) oxidation capacity of a nitrifying sludge was investigated in a sequencing batch reactor (SBR). At all initial pOHBD concentrations tested (25-400 mg C/L), both ammonium (100 mg NH_4-⁺N/L) and pOHBD were consumed with efficiencies of 99.2 ± 1.5% and 100 ±t 1%, respectively. At pOHBD concentrations lower than 100 mg C/L, the main product of ammonium oxidation was nitrate with a yield (Y_NO3) of 0.97 ± 0.03 g NO^-₃-N/g NH⁺₄-N consumed. At 200 and 400 mg pOHBD-C/L, Y_NO3 decreased to 0.78 ± 0.05 and nitrite was detected (Y_NO2 = 0.04 ± 0.01 g NO^-₂-N/g NH⁺₄-N consumed). p-Hydroxybenzoate (pOHBT) was detected as product of pOHBD oxidation. pOHBT accumulation was significant in the first operation cycles at 25 mg pOHBD-C/L. Afterward, pOHBT was completely removed and no aromatic intermediates were detected. At low C/N ratio values (0.25-4), a dissimilatory nitrifying respiratory process was maintained (Y_BM = 0.03 ± 0.01 g biomass-N/g NH⁺₄-N consumed). These results show that nitrifying SBR can be successfully used for the simultaneous removal of animonium and p-hydroxybenzaldehyde in a unique reactor. This information might be useful for treating industrial wastewaters contaminated with nitrogen and recalcitrant phenolic compounds.

Keywords : ammonium; biological oxidation; p-hydroxybenzaldehyde; nitrification; sequencing batch reactor.