Professor Byung-Taek Oh's Team Achieves Simultaneous Antibiotic Wastewater Treatment And Methane Production

Antibiotics discharged from hospitals and pharmaceutical plants mix into wastewater and cause environmental pollution. They are especially difficult to treat when multiple types are present together.

A research team from Jeonbuk National University (JBNU) led by Professor Byung-Taek Oh (Division of Biotechnology) has developed a new technology that effectively treats antibiotic-contaminated wastewater while producing bioenergy. Professor Oh and Dr. Harshavardhan Mohan (Postdoc.) led the study.

The research findings were published in the latest issue of the Chemical Engineering Journal (IF 13.2, top 3%).

To address the challenge of hard-to-treat antibiotics, the team focused on a technology called the bioelectrochemical system (BES). This technology supplements microbial activity with electrical stimulation to promote pollutant degradation.

The researchers co-cultured an antibiotic-degrading microorganism (Enterobacter sp.) with a methane-producing microorganism (Methanoculleus sp.) and applied them to the system.

As a result, under optimal conditions they succeeded in removing more than 79% of all six antibiotics while simultaneously producing methane gas. Cumulative methane production reached 7.55 ± 0.78 mmol.

Chemical oxygen demand (COD), an indicator of contamination, was also reduced by more than 91%, confirming that the antibiotics were not merely degraded but could be converted into an energy resource.¹

The mechanistic analysis is also notable. First, the ACD-08 strain that degrades antibiotics breaks them down (oxidizes) at the electrode's cathode and converts them into intermediate compounds such as volatile fatty acids (VFAs). The MB-04 strain that produces methane then uses these compounds at the anode to generate methane. In other words, a linked metabolic structure was formed in which the product of one microorganism is taken up by another to produce energy.

In addition, the electrical stimulation applied in the bioelectrochemical system enhanced interspecies electron transfer (extracellular electron transfer), increasing reaction efficiency. As a result, microbial growth and enzyme activity increased, and oxidative stress that can occur during degradation decreased, improving overall treatment performance.

In particular, comparative experiments using only the antibiotic-degrading strain or only the methane-producing strain failed to achieve both pollutant removal and energy recovery simultaneously. This shows that the synergy produced when the two strains act together in an electrochemical environment is the core of the achievement.

Dr. Harshavardhan Mohan said, "Wastewater at field sites contains multiple antibiotics, making treatment difficult. This study is meaningful because it reduces various antibiotics simultaneously while recovering methane." Professor Byung-Taek Oh added, "An integrated technology that reduces environmental pollution while producing energy is an important direction for sustainable water treatment. We will develop this into a technology applicable to real field conditions."

Meanwhile, the study has attracted attention for suggesting the possibility of transforming antibiotic wastewater from a pollutant that must simply be treated into a resource from which energy can be recovered.