Jeonbuk National University (JBNU) Professor Oh Byung-taek (Division of Biotechnology, Major in Environmental Biotechnology) and his research team succeeded in removing more than 98% of the organophosphate insecticide chlorpyrifos (CPF), a pesticide widely used worldwide.

The results of this study were published in the internationally prestigious journal Chemical Engineering Journal (Impact Factor 13.2, JCR Top 3.0%) and were thus recognized internationally. P. Sathya, a doctoral student, served as first author and led the research.

Chlorpyrifos is an insecticide widely used in agricultural fields worldwide. It persists in soil for long periods and causes serious harm to human health and ecosystems. Various removal attempts have been made to date, but technologies that secure both high efficiency and safety simultaneously have been rare.

To address this, Professor Oh’s team devised a bio-electrochemical system (BES) that combines the Streptomyces pactum (AR-8) strain with electrochemical treatment.

Experimental results showed that, compared with single microbial degradation (59.87%) or simple electrolysis (3.44%), the bio-electrochemical process achieved a degradation rate of 80.15%, and, after optimization of conditions, removal reached up to 98.54%. This level approaches near-complete detoxification (mineralization).

In particular, the team used HPLC-MS/MS analysis to elucidate pathways by which CPF is degraded into less toxic intermediates and to verify ecological safety. Earthworms were used in this verification. The experiments showed that in CPF-contaminated soil, earthworms exhibited reduced survival, growth suppression, and bioaccumulation, whereas in BES-treated soil these negative effects were greatly diminished. Notably, physiological indicators and gut microbial communities of the earthworms showed almost no adverse effects, confirming the ecological safety of the technology.

Professor Oh Byung-taek emphasized, "This study is significant not only for achieving complete degradation of residual pesticides but also for demonstrating toxicity reduction and safety as a sustainable remediation technology," adding, "It can be widely applied in the agricultural and environmental sectors."

First author P. Sathya, a doctoral student, explained, "The observed increases in enzyme activities such as esterases and OPH during the experiments indicate that microorganisms became more active when electrically stimulated. This opens new possibilities for microorganism-based pollution remediation technologies."

This achievement has been highlighted as an eco-friendly solution that can fundamentally address soil and ecosystem damage caused by pesticide contamination. The research team's BES technology is expected to establish itself as a next-generation solution for pesticide pollution remediation in an era where environmental health and food safety are of paramount importance.