This research shows that when plants contaminated with heavy metals are processed for energy production through anaerobic fermentation, adding activated carbon dramatically improves the efficiency of biogas generation. The activated carbon acts like a filter to reduce the toxic effects of heavy metals while providing surfaces for beneficial microorganisms to grow and work more effectively. The study reveals how specific bacteria and microbes adapt to these conditions, making the overall process more productive and potentially opening new possibilities for recycling contaminated plant waste into useful energy.