Toluene mineralization by denitrification in an up flow anaerobic sludge blanket (UASB) reactor

Simultaneous Elimination of Carbon and Nitrogen Compounds of Petrochemical Effluents by Nitrification and Denitrification

“…Several works focused on BTX removal have resulted in nitrite accumulation due to the low C/N ratio established (Burland & Edwards 1999;Dou et al 2008;Evans et al, 1992). This behavior is in contrast with that reported by Peña-Calva et al (2004a, 2004b and Martínez et al (2007Martínez et al ( , 2009, where BTX were converted to CO 2 whereas nitrate was reduced to N 2 at C/N ratios close to stoichiometric values. Thus, these results evidenced that complete elimination of both, carbon and nitrogen compounds will outcome with no accumulation of undesirable intermediaries if C/N ratios are close to stoichiometric values.…”

“…This situation is highly recommended for practical purposes, as operational costs by sludge disposition could be minimized. In this regard, Peña-Calva et al (2004a, 2004b, Hernández et al (2008) and Martínez et al (2007Martínez et al ( , 2009) have shown that denitrification process with BTX could be clearly dissimilative.…”

“…Different organic compounds have been used in organotrophic denitrification such as methanol, glycerol, benzoic acid, acetate, glucose, lactate (Akunna et al, 1993;CuervoLópez et al, 1999;Martínez et al, 2009). Recalcitrant compounds such as p-xylene, benzene, toluene and p-cresol have been successfully removed by organotrophic denitrification (Cervantes et al, 2009;Dou et al, 2008;Hänner et al, 1995;Martínez et al, 2007;Peña-Calva et al, 2004b). Therefore, denitrification seems a good option for treating wastewater and underground water contaminated with BTX as simultaneous removal of nitrogen and carbon compounds can be obtained.…”

“…Similarly to pH, effects of low and high temperatures are mainly related with the physicochemical changes in the cell membrane structures, either for lipids and proteins. It has been reported that toluene denitrification was performed with influents at 5 o C in a continuous UASB reactor (Martínez et al, 2007). Therefore, for obtaining a constant and acceptable denitrifying rate it is recommendable to conduct biological wastewater treatment at C/N stoichiometric values, neutral pH and temperature values between 20 and 35°C.…”

Study of the dynamics and material transformation characteristics of nitrite denitrification in UASB

“…[10,11] Moreover, it is also widely used specifically in the denitrification field. [12,13] UASB was specially designed not only to retain a high carbon level via nitrite denitrification for sludge, but also to ensure the desired condition of granular sludge formation in order to perform partial nitrification. [14] Most works focus on nitrate denitrification in UASB.…”