Kinetics of methane production and biodegradation of linear alkylbenzene sulfonate from laundry wastewater

This study evaluates the kinetics of methane production and degradation of standard linear alkylbenzene sulfonate (LAS) (50 +/- 3.5mg/L) and LAS from laundry wastewater (85 +/- 2.1mg/L) in anaerobic batch reactors at 30 degrees C with different sources of inoculum. The inocula were obtained by auto-fermentation (AFM) and UASB reactors from wastewater treatment of poultry slaughterhouse (SGH), swine production (SWT) and wastewater treatment thermophilic of sugarcane industry (THR). The study was divided into three phases: synthetic substrate (Phase I), standard LAS (Phase II) and LAS from laundry wastewater (Phase III). For SGH, the highest values for cumulative methane productions (1,844.8 +/- 149 mu molPhase II), methane production rate (70.8 +/- 88 mu mol/hPhase II and 4.01 +/- 07 mu mol/hPhase III) were observed. The use of thermophilic biomass (THR) incubated at 30 degrees C was not favorable for methane production and LAS biodegradation, but the highest kinetic coefficient degradation (k(1)(app)) was obtained for LAS (0.33 +/- 0.3h) compared with mesophilic biomass (SGH and SWT) (0.13 +/- 0.02h). Therefore, both LAS sources influenced the kinetics of methane production and organic matter degradation. For SGH, inoculum obtained the highest LAS degradation. In the SGH inoculum sequenced by MiSeq-Illumina was identified genera (VadinCA02, Candidatus Cloacamonas, VadinHB04, PD-UASB-13) related to degrade toxic compounds. Therefore, it recommended the reactor mesophilic inoculum UASB (SGH) for the LAS degradation.