The effect of ammonia concentration on the treatment of bio electrochemical leachate using MFCs technology

Abstract

AbstractMicrobial fuel cells (MFCs) have garnered attention in bio-electrochemical leachate treatment systems. The most common forms of inorganic ammonia nitrogen are ammonium ($${NH}_{4}^{ +}$$ NH 4 + ) and free ammonia. Anaerobic digestion can be inhibited in both direct (changes in environmental conditions, such as fluctuations in temperature or pH, can indirectly hinder microbial activity and the efficiency of the digestion process) and indirect (inadequate nutrient levels, or other conditions that indirectly compromise the microbial community’s ability to carry out anaerobic digestion effectively) ways by both kinds. The performance of a double-chamber MFC system—composed of an anodic chamber, a cathode chamber with fixed biofilm carriers (carbon felt material), and a Nafion 117 exchange membrane is examined in this work to determine the impact of ammonium nitrogen ($${NH}_{4}-N$$ NH 4 - N ) inhibition. MFCs may hold up to 100 mL of fluid. Therefore, the bacteria involved were analysed using 16S rRNA. At room temperature, with a concentration of 800 mg L−1 of ammonium nitrogen and 13,225 mg L−1 of chemical oxygen demand (COD), the study produced a considerable power density of 234 mWm−3. It was found that $${NH}_{4}-N$$ NH 4 - N concentrations above 800 mg L−1 have an inhibitory influence on power output and treatment effectiveness. Multiple routes removed the most nitrogen ($${NH}_{4}^{ +}$$ NH 4 + -N: 87.11 ± 0.7%, NO2–N: 93.17 ± 0.2% and TN: 75.24 ± 0.3%). Results from sequencing indicate that the anode is home to a rich microbial community, with anammox (6%), denitrifying (6.4%), and electrogenic bacteria (18.2%) making up the bulk of the population. Microbial fuel cells can efficiently and cost-effectively execute anammox, a green nitrogen removal process, in landfill leachate.