Biochar Catalytic System Degrades Ciprofloxacin in Purple Soil

Pig manure-derived biochar enhances ciprofloxacin degradation in purple soil by forming a catalytic system with endogenous hydrogen peroxide. This process generates hydroxyl radicals that break down the antibiotic, offering a sustainable solution for reducing antibiotic pollution and resistance in agricultural environments.

September 28, 2024

1–2 minutes

Chen, et al (2024)
Pig manure biocharBiochar is a carbon-rich material created from biomass decomposition in low-oxygen conditions. It has important applications in environmental remediation, soil improvement, agriculture, carbon sequestration, energy storage, and sustainable materials, promoting efficiency and reducing waste in various contexts while addressing climate change challenges. More in soil forms catalytic system with endogenous H₂O₂ to degrade ciprofloxacin in purple soil. *Chemical Engineering Journal*. https://doi.org/10.1016/j.cej.2024.156083

A recent study published in the Chemical Engineering Journal explores the potential of pig manure-derived biochar to degrade ciprofloxacin (CIP), a widely used antibiotic, in purple soil. CIP is a persistent pollutant, commonly found in agricultural soils, particularly in southwest China. Its accumulation can lead to antibiotic resistance, posing environmental and health risks.

Researchers tested biochar produced at two different temperatures—300℃ (PMC3) and 600℃ (PMC6)—and found that both enhanced CIP removal more effectively than raw pig manure. The study revealed that biochar interacts with hydrogen peroxide (H2O2) naturally produced by soil microbes, creating reactive oxygen species (ROS) like hydroxyl radicals (·OH) that break down CIP. Biochar facilitates this process by increasing H2O2 production and reducing catalase, an enzyme that normally breaks down H2O2.

Persistent free radicals in the biochar also played a key role in enhancing the degradation process. In fact, hydroxyl radicals were responsible for 72-80% of CIP breakdown in the biochar-amended soils. The study confirmed the degradation of CIP’s molecular structure, including the destruction of the piperazinyl ring, a key component of the antibiotic.

This research suggests that biochar could be a sustainable solution for CIP contamination, helping mitigate antibiotic pollution in agricultural soils without the need for external oxidants, which can cause secondary pollution.