Plastic pollution has become a global threat in the natural environment, and an urgent remedial measure is needed to reduce the negative effects caused by plastic pollutants. In the current study, the effects of pyrolysis temperature (500 °C, 700 °C, and 900 °C) and aging on the adsorption of polystyrene nanoplastics (PSNPs) onto corncob biochar were systematically assessed with kinetic, isotherm, pH-dependent adsorption experiments, FTIR and XPS spectroscopy, and DLVO calculations. The oxidation was done with 5% of HNO₃/H₂SO₄ to simulate long-term oxidative aging of biochar in the environment. The results showed that the specific surface area, hydrophobicity, and aromaticity of biochar increased with pyrolysis temperature, whereas the specific surface area and amounts of oxygen-containing groups increased after oxidation. The adsorption mechanism of PSNPs onto the biochar was explored based on the correlation between biochar properties and adsorption parameters derived from adsorption isotherms. Overall, the adsorption capacity of biochar for PSNPs increased with increased pyrolysis temperature and after aging. While the increase of specific surface area was considered the major factor leading to the increase of the adsorption, the variation in surface properties also played an important role. Pore filling, hydrophobic interaction, and hydrogen bonding may all be involved in PSNPs adsorption to biochar. However, the hydrophobic interaction might be more important for the fresh biochar, whereas hydrogen bonding involving oxygen-containing groups might make a bigger contribution to PSNPs adsorption to oxidized biochar. The pH experiments revealed that PSNPs adsorption decreased in general with the increase of pH, indicating that electrostatic repulsion played a vital role in the PSNPs adsorption process. The results of this study indicate that biochar can be potentially applied to immobilize plastic particles in terrestrial ecosystems such as in soil or groundwater, and the immobilization could be enhanced via artificial oxidation or aging of biochar in the natural environment.

塑料污染已经成为自然环境中的全球威胁，因此需要采取紧急补救措施以减少塑料污染物造成的负面影响。在本研究中，通过动力学，等温线，pH依赖性吸附，系统地评估了热解温度（500°C，700°C和900°C）和老化对聚苯乙烯纳米塑料（PSNPs）吸附在玉米芯生物炭上的影响。实验，FTIR和XPS光谱以及DLVO计算。用5％的HNO ₃ / H ₂ SO ₄进行氧化模拟环境中生物炭的长期氧化老化。结果表明，生物炭的比表面积，疏水性和芳香性随热解温度的增加而增加，而氧化后比表面积和含氧基团的数量增加。基于生物炭性质与吸附等温线得出的吸附参数之间的相关性，探讨了PSNPs在生物炭上的吸附机理。总体而言，生物炭对PSNPs的吸附能力随热解温度的升高和老化而增加。尽管认为比表面积的增加是导致吸附增加的主要因素，但表面性质的变化也起着重要的作用。毛孔填充，疏水作用，氢键可能都参与了PSNP吸附到生物炭中。但是，疏水相互作用对于新鲜生物炭可能更为重要，而涉及含氧基团的氢键可能对PSNPs吸附到氧化生物炭上的贡献更大。pH实验表明，随着pH的升高，PSNPs的吸附量总体上下降，这表明静电排斥在PSNPs的吸附过程中起着至关重要的作用。这项研究的结果表明，生物炭可以潜在地应用于将塑料颗粒固定在诸如土壤或地下水等陆地生态系统中，并且可以通过在自然环境中进行人工氧化或生物炭的老化来增强生物炭的固定性。对于新鲜生物炭而言，疏水相互作用可能更为重要，而涉及含氧基团的氢键可能对PSNPs吸附到氧化生物炭上的贡献更大。pH实验表明，随着pH的升高，PSNPs的吸附量总体上下降，这表明静电排斥在PSNPs的吸附过程中起着至关重要的作用。这项研究的结果表明，生物炭可以潜在地应用于将塑料颗粒固定在诸如土壤或地下水等陆地生态系统中，并且可以通过在自然环境中进行人工氧化或生物炭的老化来增强生物炭的固定性。对于新鲜生物炭而言，疏水相互作用可能更为重要，而涉及含氧基团的氢键可能对PSNPs吸附到氧化生物炭上的贡献更大。pH实验表明，随着pH的升高，PSNPs的吸附量总体上下降，这表明静电排斥在PSNPs的吸附过程中起着至关重要的作用。这项研究的结果表明，生物炭可以潜在地应用于将塑料颗粒固定在诸如土壤或地下水等陆地生态系统中，并且可以通过在自然环境中进行人工氧化或生物炭的老化来增强生物炭的固定性。pH实验表明，随着pH的升高，PSNPs的吸附量总体上下降，这表明静电排斥在PSNPs的吸附过程中起着至关重要的作用。这项研究的结果表明，生物炭可以潜在地应用于将塑料颗粒固定在诸如土壤或地下水等陆地生态系统中，并且可以通过在自然环境中进行人工氧化或生物炭的老化来增强生物炭的固定性。pH实验表明，随着pH的升高，PSNPs的吸附量总体上下降，这表明静电排斥在PSNPs的吸附过程中起着至关重要的作用。这项研究的结果表明，生物炭可以潜在地应用于将塑料颗粒固定在诸如土壤或地下水等陆地生态系统中，并且可以通过在自然环境中进行人工氧化或生物炭的老化来增强生物炭的固定性。