Biological treatment of propanil and 3,4-dichloroaniline: Kinetic and microbiological characterisation

• Published in: Water research (Oxford) Vol. 44; no. 17; pp. 4980 - 4991
• Main Authors: Carvalho, G., Marques, R., Lopes, A.R., Faria, C., Noronha, J.P., Oehmen, A., Nunes, O.C., Reis, M.A.M.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Kidlington Elsevier Ltd 01-09-2010; Elsevier
• Subjects: 3,4-Dichloroaniline; Aniline Compounds - isolation & purification; Applied sciences; Bacteria - genetics; Bacteria - growth & development; Bacteria - isolation & purification; Bacteria - metabolism; Biodegradation; Biodegradation rates; Biodegradation, Environmental; Biological; Biomass; Bioreactors - microbiology; Carbon; Denaturing Gradient Gel Electrophoresis; DGGE; Ecology; Enrichment; Exact sciences and technology; Feeding; Herbicides; Kinetics; Microbial population analysis; Microorganisms; Other industrial wastes. Sewage sludge; Phylogeny; Pollution; Principal Component Analysis; Propanil; Propanil - isolation & purification; Strategy; Wastes; Water treatment and pollution; Xenobiotics; Herbicides; Microbial population analysis; Propanil; Biodegradation rates; Xenobiotics; DGGE; 3,4-Dichloroaniline; Waste treatment; Biological purification; Health and environment; Batchwise; Sequencing batch reactor; Bacteria; Micrococcales; Agriculture; Paddy field; Biological treatment; Public health; Xenobiotic; Organic compounds; Biodegradation; Enterococcus; Pollutant behavior; Pesticides; Denaturing gradient gel electrophoresis; Herbicide; Streptococcaceae; Bioreactor; Water pollution; Kinetics
• ISSN: 0043-1354; 1879-2448
• DOI: 10.1016/j.watres.2010.08.006

Propanil (3,4-dichloropropionanilide) is a widely used herbicide, applied worldwide in rice paddies. Propanil is primarily transformed in nature to 3,4-dichloroaniline (DCA), which is more slowly biodegradable. Both compounds have adverse health and ecotoxicity effects. This work investigated the microbial ecology and kinetics of propanil-degrading enrichments obtained from soil in a sequencing batch reactor (SBR) operated with different feeding strategies, aiming at the enhanced biological removal of propanil and DCA from contaminated waters.
During SBR operation with a dump feeding strategy, a high propanil concentration led to DCA accumulation, which was only fully degraded after 5 days, likely due to DCA inhibition. For this reason, the operational mode was changed to fed-batch operation with lower initial propanil concentrations, which resulted in faster propanil and DCA biodegradation. Thus a fed-batch operation seems more appropriate for the acclimatisation of an effective propanil- and DCA-degrading population.
The changes in performance were accompanied by a shift in the microbial population structure, as determined by DGGE of the 16S rRNA gene, particularly after a feed of DCA as the sole carbon source. Isolates obtained from the acclimatised population included members of the genera
Enterococcus and
Rhodococcus, as well as
Brevundimonas, which displayed >90% propanil biodegradation efficiency.