Portal de Periódicos da CAPES

Enhanced anaerobic degradability of highly polluted pesticides-bearing wastewater under thermophilic conditions

2017; Elsevier BV; Volume: 339; Linguagem: Inglês

10.1016/j.jhazmat.2017.06.032

1873-3336

N. García-Mancha, Victor M. Monsalvo, Daniel Puyol, Juan J. Rodrı́guez, A.F. Mohedano,

Advanced oxidation water treatment

This work presents a sustainable and cost-competitive solution for hardly biodegradable pesticides-bearing wastewater treatment in an anaerobic expanded granular sludge bed (EGSB) reactor at mesophilic (35°C) and thermophilic (55°C). The reactor was operated in continuous mode during 160days, achieving an average COD removal of 33 and 44% under mesophilic and thermophilic conditions, respectively. The increase of temperature improved the biomass activity and the production of methane by 35%. Around 96% of pesticides identified in raw wastewater were not detected in both mesophilic and thermophilic effluents. A dramatic selection of the microbial population in anaerobic granules was caused by the presence of pesticides, which also changed significantly when the temperature was increased. Pesticides caused a significant inhibition on methanogenesis, especially over acetoclastic methanogens. Aerobic biodegradability tests of the resulting anaerobic effluents revealed that aerobic post-treatment is also a feasible and effective option, yielding more than 60% COD reduction.