A kinetics study on the biodegradation of synthetic wastewater simulating effluent from an advanced oxidation process using Pseudomonas putida CECT 324.
Bacterial growth on mixed substrates is employed for wastewater treatment. Biodegradation kinetics of Pseudomonas putida CECT 324 growth on formic acid, vanillin, phenol and oxalic acid mixtures is described. The experiments were carried out in a stirred-tank fermentor in batch mode at different temperatures (25, 30 and 35 degrees C) and pH (5, 6 and 7). The four compounds selected are typical intermediates in pesticide-contaminated water treated by advanced oxidation processes (AOPs). The toxicity of intermediates was investigated for a combined AOP-biological treatment, and the minimum DOC inhibitory concentration of the intermediate mixture was 175 ppm. The resulting biodegradation and growth kinetics were best described by the sum kinetics with interaction parameters (SKIP) model. Phenol and oxalic acid inhibit P. putida growth, and formic acid consumption strongly affects the biodegradation of oxalic acid. At all the temperatures tested and at pH between 5 and 7, P. putida CECT 324 was able to degrade the four substrates after culture times of 30 h at 30 degrees C and pH 7, which were the best conditions, and after 70 h, under the worst, at 35 degrees C.
Martín
M M Ballesteros
MM
Department of Chemical Engineering, University of Almería, 04120 Almería, Spain. mmenta@ual.es
Pérez
J A Sánchez
JA
Fernández
F G Acién
FG
Sánchez
J L García
JL
López
J L Casas
JL
Rodríguez
S Malato
SM
D001673:Biodegradation, Environmental; D019149:Bioreactors; D002264:Carboxylic Acids / Q000737:chemistry; D004867:Equipment Design; D005285:Fermentation; D007700:Kinetics; D015233:Models, Statistical; D010100:Oxygen / Q000737:chemistry*; D016958:Pseudomonas putida / Q000378:metabolism*; D013696:Temperature; D013997:Time Factors; D014865:Waste Disposal, Fluid / Q000379:methods*; D014874:Water Pollutants, Chemical / Q000032:analysis; D018508:Water Purification / Q000379:methods*
D002264:Carboxylic Acids; D014874:Water Pollutants, Chemical; D010100:Oxygen