Thermophilic biomethanization of agricultural waste in codigestion: effect of pesticides
Resumen: Anaerobic digestion (AD) is becoming one of the most feasible and efficient options for agroindustrial waste management. However, this kind of waste can contain certain substances from the industrial activity, which could potentially inhibit or, at least, modify the biomethanization process. Pesticides are widely used in agricultural activities. Mancozeb is an ethylene dithiocarbamate fungicide with broad spectrum used in crops. It reacts with and inactivates sulfhydryl groups of aminoacids and enzymes of fungal cells, disrupting of respiration, lipid metabolism and production of energy. Tefluthrin is a synthetic pyrethroid insecticide used to control a wide range of soil pests. It causes neurotoxicity and is a sodium channel modulator. This paper assesses the influence of the presence of mancozeb and
tefluthrin on thermophilic (55°C) anaerobic co-digestion (carrot, cabbage, green pea, artichoke and fava and broad bean) of synthetic agroindustrial waste. The main results show that the pesticides improve the biomethanization process referred to generation of biogas (123%), consumption of volatile solid -VS- (18%), removal of chemical oxygen demand (5%) and yield of biogas measured like mL biogas/ VS consumed (117%), between other parameters. Anaerobic codigestion on presence of pesticides seems feasible and improved in comparison with the codigestion without these substances.