Rahim Hafeez Ur, Allevato Enrica, Stazi Silvia Rita
Department of Chemical, Pharmaceutical and Agricultural Sciences (DOCPAS), University of Ferrara, 44121 Ferrara, Italy.
Department of Environmental and Prevention Sciences (DiSAP), University of Ferrara, 44121 Ferrara, Italy.
J Environ Manage. 2024 Nov;370:122670. doi: 10.1016/j.jenvman.2024.122670. Epub 2024 Oct 3.
The development of innovative, eco-friendly, and cost-effective adsorbents is crucial for addressing the widespread issue of organic and inorganic pollutants in soil and water. Recent advancements in sulfur reagents-based materials, such as FeS, MoS, MnS, S, CS, NaS, NaSO, HS, S-nZVI, and sulfidated Fe, have shown potential in enhancing the functional properties and elemental composition of biochar for pollutant removal. This review explores the synthesis and characterization of sulfur reagents/species functionalized biochar (S-biochar), focusing on factors like waste biomass attributes, pyrolysis conditions, reagent adjustments, and experimental parameters. S-biochar is enriched with unique sulfur functional groups (e.g., C-S, -C-S-C, C=S, thiophene, sulfone, sulfate, sulfide, sulfite, elemental S) and various active sites (Fe, Mn, Mo, C, OH, H), which significantly enhance its adsorption efficiency for both organic pollutants (e.g., dyes, antibiotics) and inorganic pollutants (e.g., metal and metalloid ions). The literature analysis reveals that the choice of feedstock, influenced by its lignocellulosic content and xylem structure, critically impacts the effectiveness of pollutant removal in soil and water. Pyrolysis parameters, including temperature (200-600 °C), duration (2-10 h), carbon-to-hydrogen (C:H) and oxygen-to-hydrogen (O:H) ratios in biochar, as well as the biochar-to-sulfur reagent modification ratio, play key roles in determining adsorption performance. Additionally, solution pH (2-8) and temperature (288, 298, and 308 K) affect the efficiency of pollutant removal, though optimal dosages for adsorbents remain inconsistent. The primary removal mechanisms involve physisorption and chemisorption, encompassing adsorption, reduction, degradation, surface complexation, ion exchange, electrostatic interactions, π-π interactions, and hydrogen bonding. This review highlights the need for further research to optimize synthesis protocols and to better understand the long-term stability and optimal dosage of S-biochar for practical environmental applications.
开发创新、环保且经济高效的吸附剂对于解决土壤和水中有机和无机污染物广泛存在的问题至关重要。基于硫试剂的材料，如FeS、MoS、MnS、S、CS、NaS、NaSO、HS、S-nZVI和硫化铁，最近的进展表明，它们在增强生物炭的功能特性和元素组成以去除污染物方面具有潜力。本综述探讨了硫试剂/物种功能化生物炭（S-生物炭）的合成与表征，重点关注诸如废弃生物质属性、热解条件、试剂调整和实验参数等因素。S-生物炭富含独特的硫官能团（如C-S、-C-S-C、C=S、噻吩、砜、硫酸盐、硫化物、亚硫酸盐、元素硫）和各种活性位点（Fe、Mn、Mo、C、OH、H），这显著提高了其对有机污染物（如染料、抗生素）和无机污染物（如金属和类金属离子）的吸附效率。文献分析表明，受木质纤维素含量和木质部结构影响的原料选择对土壤和水中污染物去除的有效性至关重要。热解参数，包括温度（200-600°C）、持续时间（2-10小时）、生物炭中的碳氢（C:H）和氧氢（O:H）比，以及生物炭与硫试剂的改性比，在决定吸附性能方面起着关键作用。此外，溶液pH值（2-8）和温度（288、298和308K）会影响污染物去除效率，尽管吸附剂的最佳用量仍不一致。主要去除机制包括物理吸附和化学吸附，涵盖吸附、还原、降解、表面络合、离子交换、静电相互作用、π-π相互作用和氢键。本综述强调需要进一步研究以优化合成方案，并更好地了解S-生物炭在实际环境应用中的长期稳定性和最佳用量。
