Enhancing methane production by adding Fe3+ in mesophilic anaerobic digestion of cheese waste

The advancements in cheese production technology have resulted in increased waste generation, especially in the form of liquid byproducts left over after the milk clotting process. This research examines the possibility of using cheese waste to produce methane (CH4) through mesophilic anaerobic digestion and investigates how adding iron (Fe) can improve CH4. Field experiments were conducted to evaluate the effects of varying concentrations of cheese waste (0–33.33 g/L) and FeCl3 (0–3.0 g/L) on CH4 yield. Results revealed that the addition of 2 g/L FeCl3 achieved the highest cumulative CH4 yield and production rate, with increases of 68% and 65% over the control, respectively. The study also monitored pH levels and found that the best treatment maintained a near-neutral pH of 6.79 by day 50, which is important for sustaining effective microbial activity. This study highlights the potential of incorporating Fe supplementation to optimize CH4 yields from cheese waste and other organic substrates, contributing to more sustainable and efficient renewable energy production.