Enhanced methane production in anaerobic co-digestion systems with modified black phosphorus

Black phosphorus (BP) and BP modified by hydrogen peroxide (MBP) were used as accelerants to enhance CH4 production and CO2 reduction in microbial electrolysis cells (MECs) coupled with anaerobic co-digestion systems (MEC-AcoD). The MEC-AcoD group with a voltage of 0.6 V and 0.03 wt.% of MBP accelerant (MEC0.6MBP0.03) had the largest CH4 yield (242.1 mL/g VS) and the smallest carbon dioxide yield (97.6 mL/g VS) compared with the control group (141.2 mL/g VS, 146.9 mL/g VS). The digestates that used MEC0.6MBP0.03 exhibited superior thermal stability (46.2 %) and total nutrient contents (44.5 g/kg). These improvements may be attributed to the superior electron exchange capacity and physicochemical properties of MBP. Herein, we propose a strategy to understand enhanced CH4 production and CO2 reduction in anaerobic co-digestion and MEC-AcoD systems using MBP accelerants. Notably, combining MBP and MEC could effectively promote anaerobic co-digestion performance.

Automated summary

The use of black phosphorus and black phosphorus modified by hydrogen peroxide as accelerants in microbial electrolysis cells coupled with anaerobic co-digestion systems can enhance methane production and carbon dioxide reduction. The MEC-AcoD system with a voltage of 0.6 V and 0.03 wt.% of MBP accelerant showed the highest methane yield (242.1 mL/g VS) and the lowest carbon dioxide yield (97.6 mL/g VS). The digestates using this accelerant exhibited superior thermal stability (46.2%) and total nutrient contents (44.5 g/kg).