2,4,6-Trichlorophenol and phenol removal in methanogenic and partially-aerated methanogenic conditions in a fluidized bed bioreactor

✍ Scribed by Claudio Garibay-Orijel; Elvira Ríos-Leal; Jaime García-Mena; Héctor Mario Poggi-Varaldo

• Book ID: 102315511
• Publisher: Wiley (John Wiley & Sons)
• Year: 2005
• Tongue: English
• Weight: 163 KB
• Volume: 80
• Category: Article
• ISSN: 0268-2575
• DOI: 10.1002/jctb.1313

✦ Synopsis

Abstract

A fluidized bed bioreactor (FBBR) was operated for more than 575 days to remove 2,4,6‐trichlorophenol (TCP) and phenol (Phe) from a synthetic toxic wastewater containing 80 mg L^−1^ of TCP and 20 mg L^−1^ of Phe under two regimes: Methanogenic (M) and Partially‐Aerated Methanogenic (PAM). The mesophilic, laboratory‐scale FBBR consisted of a glass column (3 L capacity) loaded with 1 L of 1 mm diameter granular activated carbon colonized by an anaerobic consortium. Sucrose (1 g COD L^−1^) was used as co‐substrate in the two conditions. The hydraulic residence time was kept constant at 1 day. Both conditions showed similar TCP and Phe removal (99.9 + %); nevertheless, in the Methanogenic regime, the accumulation of 4‐chlorophenol (4CP) up to 16 mg L^−1^ and phenol up to 4 mg L^−1^ was observed, whereas in PAM conditions 4CP and other intermediates were not detected. The specific methanogenic activity of biomass decreased from 1.01 ± 0.14 in M conditions to 0.19 ± 0.06 mmolCH~4~ h^−1^ gTKN^−1^ in PAM conditions whereas the specific oxygen uptake rate increased from 0.039 ± 0.008 in M conditions to 0.054 ± 0.012 mmolO~2~ h^−1^ gTKN^−1^, which suggested the co‐existence of both methanogenic archaea and aerobic bacteria in the undefined consortium. The advantage of the PAM condition over the M regime is that it provides for the thorough removal of less‐substituted chlorophenols produced by the reductive dehalogenation of TCP rather than the removal of the parent compound itself. Copyright © 2005 Society of Chemical Industry