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Performance of a down‐flow fluidized bed reactor under sulfate reduction conditions using volatile fatty acids as electron donors
Author(s) -
CelisGarcía Lourdes B.,
RazoFlores Elías,
Monroy Oscar
Publication year - 2007
Publication title -
biotechnology and bioengineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.136
H-Index - 189
eISSN - 1097-0290
pISSN - 0006-3592
DOI - 10.1002/bit.21288
Subject(s) - methanogenesis , sulfate , chemistry , propionate , sulfide , bioreactor , chemical oxygen demand , packed bed , fluidized bed , wastewater , chromatography , methane , waste management , organic chemistry , engineering
The use of a down‐flow fluidized bed (DFFB) reactor for the treatment of a sulfate‐rich synthetic wastewater was investigated to obtain insight into the outcome of sulfate reduction in a biofilm attached to a plastic support under a down‐flow regime. Fine low‐density polyethylene particles were used as support for developing a biofilm within the reactor. The reactor treated a volatile fatty acids mixture of acetate or lactate, propionate, and butyrate at different chemical oxygen demand (COD) to sulfate ratios ranging from 1.67 to 0.67 (g/g). Organic loading rate changed from 2.5 to 5 g COD/L · day and sulfate loading rate increased from 1.5 to 7.3 g SO 4 2‐ /L · day. At the beginning of continuous operation, methanogenesis was the predominant process; however, after 187 days, sulfate reduction became the main ongoing biological process. After 369 days, a COD removal of 93% and a sulfate removal of 75% were reached. Total sulfide concentrations in the reactor ranged from 105, when the reactor was mainly methanogenic, to around 1,215 mg/L at the end of the experiment. The high sulfide concentrations did not affect the performance of the reactor. Results demonstrated that the configuration of the DFFB reactor was suitable for the anaerobic treatment of sulfate‐rich wastewater. Biotechnol. Bioeng. 2007;97: 771–779. © 2006 Wiley Periodicals, Inc.