Boosting Chlorination of Diclofenac with Sludge-Derived Biochar

Sludge-derived biochar (SBC) enhances chlorination of diclofenac in water treatment. Carbon-centered persistent free radicals in SBC boost reactive species production, improving chlorination efficiency, reducing toxicity, and offering a sustainable, eco-friendly solution for eliminating emerging micropollutants.

June 8, 2024

1–2 minutes

Xu, et al (2024) Unraveling the intrinsic activity origin of sludge-derived 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 for boosted chlorination of diclofenac: Key role of persistent free radicals. Separation and Purification Technology. https://doi.org/10.1016/j.seppur.2024.127965

A recent study published in Separation and Purification Technology reveals a groundbreaking method to enhance chlorination in water treatment using sludge-derived biochar (SBC). The research, led by Jiaxin Xu and colleagues, explores the intrinsic activity of SBC, focusing on its role in boosting the chlorination of diclofenac, a common and toxic micropollutant found in wastewater.

The study highlights the pivotal role of carbon-centered persistent free radicals (PFRs) present in SBC. These radicals facilitate electron transfer, enhancing the production of reactive species such as hydroxyl radicals (•OH) and chlorine radicals (ClO•). These reactive species significantly improve the oxidative degradation of diclofenac across a pHpH is a measure of how acidic or alkaline a substance is. A pH of 7 is neutral, while lower pH values indicate acidity and higher values indicate alkalinity. Biochars are normally alkaline and can influence soil pH, often increasing it, which can be beneficial More range of 5.0 to 11.0.

Electron spin resonance and electrochemical tests confirmed that PFRs in SBC mediate electron transfer to free available chlorine (FAC) and dissolved oxygen. This interaction generates multiple reactive oxygen species (ROS) and boosts the overall chlorination process. Additionally, the study found that the regeneration of PFRs by FAC and electron-rich diclofenac enhances the reusability and efficiency of SBC in chlorination.

The SBC/FAC system developed in this study offers a more effective alternative to traditional chlorination, which often struggles with emerging micropollutants and produces toxic byproducts. The SBC method not only improves chlorination efficiency but also reduces toxicity and interference, making it a viable and eco-friendly solution for water treatment.

This innovative approach utilizing SBC as a catalyst for chlorination presents a promising advancement in the field of water purification. The study provides new insights into the activation potential of PFRs and underscores the importance of sustainable and efficient methods in addressing global water quality issues.