Psychrophilic anaerobic digestion emerges as an appealing integrated solution for the management of agricultural waste, particularly for farmers in regions where the average temperature does not exceed 26 °C, as seen in coffee cultivation. Therefore, this study seeks to assess the biomethane potential of thermochemical-treated coffee husk through psychrophilic anaerobic digestion (C3-20 °C-w/pretreatment). To examine its viability, outcomes were compared with reactors operating at both mesophilic (C1-35 °C) and psychrophilic (C2-20 °C) conditions, albeit without the use of pretreated coffee husk. The C3-20 °C-w/pretreatment test demonstrated a 36.89% increase (150.47 NmL CH₄/g VS; 161.04 NmL CH₄/g COD), while the C1-35 °C test exhibited a 24.03% increase (124.99 NmL CH₄/g VS; 133.77 NmL CH₄/g COD), both in comparison to the C2-20 °C test (94.96 NmL CH₄/g VS; 101.63 NmL CH₄/g COD). Notably, the C3-20 °C-w/pretreatment trial yielded superior outcomes, accompanied by an associated energy output of 3199.25 GWh/year, sufficient to meet the annual energy demands of 494 residences. This marks an increase of 83 and 182 million residences compared to the mesophilic and psychrophilic AD of CH without pretreatment, respectively.

PSLer is designed to utilize commercial boards and open-source code to deliver and capture voltage in microbial electrolysis systems. This applied voltage enhances microbial metabolic processes, allowing the microbial cells to generate electrical power, which the device captures and records. Effective operation, optimization, and troubleshooting of microbial electrolysis cells rely on power suppliers and multimeters with data acquisition capabilities to ensure dependable performance and efficient resource use. In this context, the manuscript describes the development of an automatic monitoring device that incorporates a Power Supply Unit, Arduino UNO, and ADS1256 boards, with an assembly cost less than $300 American dollars. This cost-effective solution empowers researchers with limited budgets to conduct dependable and efficient research. Additionally, the manuscript provides detailed instructions for assembling and using the monitoring device. This innovative prototype overcomes the limitations of costly and inflexible commercial devices and fosters interdisciplinary research, ultimately saving time and reducing costs.