ABSTRACT Methane production from agro‐industrial wastewater represents an important opportunity for renewable energy generation and waste valorization. In this study, methane production from four agro‐industrial wastewaters—nejayote (corn nixtamalization wastewater), dairy, poultry, and swine—was evaluated through batch biodegradability assays under mesophilic conditions and kinetic modeling. The highest methane production capacity was obtained from nejayote wastewater (325 L CH 4 kg −1 VSS), followed by swine (223 L CH 4 kg −1 VSS), dairy (181 L CH 4 kg −1 VSS), and poultry wastewater (131 L CH 4 kg −1 VSS). Methane production kinetics were successfully described using first‐order, logistic, and modified Gompertz models. Among them, the modified Gompertz model provided the best fit for at least three of the evaluated substrates, including nejayote, particularly due to its accurate prediction of lag phase and methane production rate. Pearson correlation analysis revealed a strong positive relationship between alkalinity and both total chemical oxygen demand (CODt) ( r 2 = 0.98, p < 0.05) and methane production ( r 2 = 0.97, p < 0.05). Conversely, ammonium exhibited a negative correlation with methane yield ( r 2 = −0.75, p < 0.05). These results demonstrate the high anaerobic biodegradability of nejayote wastewater and provide valuable parameters for the design and optimization of methane production systems using agro‐industrial effluents.
Maldonado‐Escalante et al. (Sun,) studied this question.