Ge, et al (2024) Mitigation of asphalt volatile organic compounds emissions and health hazards using a TiO₂-doped 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: Microscopic and physiological insights. Environmental Technology & Innovation. https://doi.org/10.1016/j.eti.2024.103763

Asphalt is a key material in pavement construction due to its waterproofing, adhesive, and durable properties. However, its production and use release harmful volatile organic compounds (VOCs), posing significant health risks. Researchers have developed a novel composite, combining titanium dioxide (TiO2) with biochar, to address this issue. This composite aims to reduce VOC emissions and mitigate associated health hazards.

The TiO2-biochar composite enhances the physical properties of asphalt, increasing its softening point by about 6°C and improving thermal stability and deformation resistance. These changes contribute to better pavement performance. Analytical techniques, such as headspace-gas chromatography/mass spectrometry (HS-GC/MS), revealed that the composite significantly reduces VOC emissions by over 80%, particularly targeting harmful compounds like alkanes, cycloalkanes, and aromatic hydrocarbons. The TiO2-biochar modified asphalt exposed to UV light (TUBC) showed the most pronounced effect.

To assess the health benefits, the composite’s cytotoxicity was tested using human bronchial epithelial (BEAS-2B) cells. The results indicated that the composite maintained higher cell viability and reduced reactive oxygen species (ROS) levels. This reduction in oxidative stress and inflammation is crucial in minimizing the health risks associated with VOC exposure. The composite’s effectiveness is attributed to its high adsorption capacity and photocatalytic degradation under UV light, breaking down VOCs into less harmful substances.

The study underscores the dual mechanism of the TiO2-biochar composite in mitigating VOC emissions. Biochar’s large surface area and 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 enable effective adsorption of VOCs, while TiO2’s photocatalytic properties degrade these compounds. Microscopic analysis confirmed the uniform dispersion of the composite in the asphalt matrix, essential for efficient decontamination.

In vitro assays further demonstrated the composite’s potential in reducing cellular toxicity. BEAS-2B cells exposed to various concentrations of asphalt VOCs exhibited lower viability with increased VOC exposure. However, cells exposed to TUBC showed significantly higher viability, indicating reduced cytotoxicity. The study also measured mRNA levels of key biomarkers, such as CYPIA1, ROS, GST-3, EPHX1, and IL-1β, which are associated with VOC-induced cellular toxicity. The TiO2-biochar composite effectively lowered the levels of these biomarkers, aligning with its VOC reduction capabilities.

The findings establish the TiO2-biochar composite as a promising solution for creating greener and safer asphalt. Future research will focus on optimizing the composite and validating its performance in real-world applications. This innovation not only improves pavement quality but also offers significant environmental and health benefits, especially for workers exposed to asphalt fumes.

In conclusion, the TiO2-biochar composite represents a significant advancement in asphalt modification. By reducing VOC emissions and associated health risks, it promotes safer construction practices and contributes to environmental sustainability. As research continues, this composite could become a standard in the industry, enhancing both infrastructure and public health.