Large amounts of biomass waste were harvested from constructed wetlands and had to be treated and disposed of. In this study, a one-step hydrothermal carbonization (HTC) process was utilized to dispose of such biomass waste and prepare high-performance adsorption adsorbents with the assistance of sulfuric acid. The experimental parameters were optimized through response surface methodology (RSM) to achieve excellent adsorption performance for methylene blue and mass yield. Based on the RSM results, an HTC product (HTC70–2) obtained under the optimal conditions of 70 wt % sulfuric acid concentration and 2 h of reaction time had shown maximum adsorption capacity (Q_max = 384.08 mg/g) and a higher mass yield (42.90 ± 3.29%). The optimized products were analyzed by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and Brunauer–Emmett–Teller (BET) analysis. The results showed that HTC70–2 had rough surfaces formed by nanoparticles, developed pore structures, and abundant functional groups. Moreover, the adsorption capacity of the sample decreased by only 12.8% after five adsorption–desorption cycle experiments, showing an outstanding renewable performance. FTIR, XPS, and zeta potential analysis were used to investigate the adsorption mechanisms, revealing that electrostatic attraction and surface complexation played a main role in the adsorption process.

中文翻译：

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酸性条件下 Ceratophyllum demersum 的一步法水热碳化制备高性能吸附剂


大量的生物质废弃物是从人工湿地中收获的，必须进行处理和处置。在本研究中，采用一步水热碳化 （HTC） 工艺处理此类生物质废弃物，并在硫酸的帮助下制备高性能吸附吸附剂。通过响应面法 （RSM） 优化实验参数，以获得优异的亚甲基蓝吸附性能和质量产率。根据 RSM 结果，在 70 wt % 硫酸浓度和 2 h 反应时间的最佳条件下获得的 HTC 产物 （HTC70-2） 显示出最大的吸附容量 （Q_max = 384.08 mg/g） 和更高的质量产率 （42.90 ± 3.29%）。通过扫描电子显微镜 （SEM） 、傅里叶变换红外光谱 （FTIR） 和 Brunauer-Emmett-Teller （BET） 分析对优化后的产物进行分析。结果表明，HTC70-2 具有纳米颗粒形成的粗糙表面、发达的孔隙结构和丰富的官能团。此外，经过 5 次吸附-脱附循环实验后，样品的吸附容量仅下降了 12.8%，显示出出色的可再生性能。采用 FTIR、XPS 和 zeta 电位分析研究吸附机理，揭示静电吸引和表面络合在吸附过程中起主要作用。