The pervasive presence of pharmaceutical and personal care products (PPCPs) in aquatic environments poses a significant and growing threat to both natural ecosystems and human health. Among these contaminants, ibuprofen (IBP), a widely used nonsteroidal anti-inflammatory drug, is particularly concerning. While extensively consumed for pain relief, a substantial 85% of ingested IBP remains unabsorbed by the human body and is subsequently excreted into the environment. Current urban water treatment facilities frequently overlook these discharged PPCPs, leading to their accumulation in water bodies. Research indicates that IBP can impair the reproduction and development of aquatic animals , disrupt the human immune system, lead to central nervous system disorders, and intensify organ dysfunction, highlighting an urgent need for effective removal strategies. A recent study published in Frontiers of Environmental Science & Engineering by Zhixian Zhou, Zhengxiang Li, Chenman Shi, Wenlong Zhang, Jiangtao Feng, Wei Yan, and Hongjie Wang, introduces a groundbreaking solution: a novel 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 composite capable of dramatically enhancing IBP adsorption from water.

Adsorption technology is recognized as a practical, low-cost, and safe method for removing PPCPs like IBP from water. Biochar is a promising adsorbent due to its porous structure and affinity for organic pollutants. However, the efficacy of traditional biochar is often limited by its low porosityPorosity of biochar is a key factor in its effectiveness as a soil amendment and its ability to retain water and nutrients. Biochar’s porosity is influenced by feedstock type and pyrolysis temperature, and it plays a crucial role in microbial activity and overall soil health. Biochar More and specific surface area, which constrain its adsorption capacity for IBP. To overcome these limitations, the research team developed a polyaniline/acid-impregnated reed biochar (PANI/H-BC) composite. This innovative material was synthesized through in-situ polymerization, integrating nitrogen-rich polyaniline particles onto reed biochar produced via rapid pyrolysisPyrolysis is a thermochemical process that converts waste biomass into bio-char, bio-oil, and pyro-gas. It offers significant advantages in waste valorization, turning low-value materials into economically valuable resources. Its versatility allows for tailored products based on operational conditions, presenting itself as a cost-effective and efficient More. This strategic modification aimed to enhance both the porosity and surface functional groups of the adsorbent.

The results of their adsorption experiments were remarkable. The PANI/H-BC composite demonstrated a maximum IBP adsorption capacity of 35.58 mg/g. This represents a significant improvement, with the composite performing 4.3 times better than polyaniline (PANI) alone and an impressive 3.7 times better than unmodified biochar (BC). Furthermore, the speed of adsorption was dramatically increased; PANI/H-BC achieved adsorption equilibrium within a mere 30 minutes, representing a 50% reduction in equilibrium time compared to traditional biochar. Critically, the composite proved highly reusable, retaining substantial adsorption capacity even after ten adsorption-desorption cycles.

The enhanced performance of PANI/H-BC is attributed to a synergistic combination of mechanisms. Microscopic analysis revealed that while unmodified biochar had a relatively smooth surface, the PANI/H-BC composite displayed a distinctive porous, network-like fibrous structure with irregular and rough surfaces. This increased roughness and porosity provide a greater number of active sites for IBP molecules to bind. Moreover, the loading of PANI successfully transformed the biochar adsorbent surface from hydrophobic to hydrophilic. The contact angle, a measure of hydrophilicity, decreased from 144.273° for H-BC to 88.568° for PANI/H-BC. This change is crucial because IBP, being hydrophilic when solution 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 exceeds its pKa of 4.91, interacts more effectively with a hydrophilic adsorbent surface. The improved dispersion and stability of the modified adsorbent in aqueous solutions lead to an increased contact area with IBP molecules, facilitating more effective interactions. The study further elucidated that the enhanced adsorption performance is the result of multiple molecular interactions, including π-π conjugation, hydrogen bonding, and electrostatic interactions between the adsorbent and IBP molecules. Beyond its impressive performance, a production cost assessment confirmed the practical application potential of PANI/H-BC, emphasizing its low cost and renewability.

This research offers substantial theoretical support for the development of advanced adsorbents for IBP removal and provides a practical, efficient, and cost-effective method for mitigating pharmaceutical pollution in water bodies. The PANI/H-BC composite represents a significant stride towards sustainable environmental engineering solutions, contributing to safer water resources and a healthier environment.

Source: Zhou, Z., Li, Z., Shi, C., Zhang, W., Feng, J., Yan, W., & Wang, H. (2025). Insight into the enhanced adsorption behavior and mechanism of ibuprofen from water on polyaniline/acid-impregnated reed biochar composite. Frontiers of Environmental Science & Engineering, 19(10), 135.