Performance evaluation of self-designed Nickel oxide/Biochar nano-magnetic coating reactor for anaerobic digestion of...

Considering the issues of low methane yield and high energy consumption in traditional anaerobic digestion systems. This study developed a novel nano-magnetic coating reactor by depositing nickel oxide/biochar onto the reactor surface and installing North Pole-South Pole alternately arranged magnets on the agitator blades, thereby introducing eddy currents into the anaerobic digestion system. Experimental results indicate that at an optimal organic loading rate of 8 g VS L^-1·d^-1, the volumetric methane yield in the nano-magnetic coating reactor reached 1.22 L L^-1·d^-1, representing a 32.61 % increase compared to ordinary fermentation reactor. The dominant bacterial strains, including Streptococcus, DMER64 and Candidatus_Methanomethylicus, obviously improved direct interspecies electron transfer efficiency and methane metabolism capacity in the system. The novel nano-magnetic coating reactor developed in this study enhances methane yield through an endogenous electric field while reducing energy consumption, exploring new strategies for multidisciplinary collaboration in biogas applications.