Yang Zhengming, Charoenkal Khantaphong, Wang Zhuochao, Xu Yang, Li Taiwen, Xu Tianyu, Li Qiang, Sun Xuecheng, Lin Shan, Cao Hongliang
Key Laboratory of Smart Farming for Agricultural Animals, Ministry of Agriculture and Rural Affairs, College of Engineering, Huazhong Agricultural University, No. 1, Shizishan Street, Hongshan District, Wuhan, 430070, PR China.
Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture and Rural Affairs, College of Resources and Environment, Huazhong Agricultural University, No. 1, Shizishan Street, Hongshan District, Wuhan, 430070, PR China.
J Environ Manage. 2025 Jun;386:125776. doi: 10.1016/j.jenvman.2025.125776. Epub 2025 May 15.
Biochar has shown considerable potential for removing ammonium (NH) from wastewater, supporting sustainable pollution control and nutrient recovery. However, optimizing biochar structure remains challenging, especially concerning the interplay between pore structure, surface functional groups, and NH adsorption mechanisms. This study addresses these challenges by investigating the adsorption mechanism of NH on biochar with nitrogen (N)- and oxygen (O)-doped groups, as well as hierarchical pores, through density functional theory (DFT) calculations and molecular dynamics (MD) simulations. The results reveal a significant enhancement in NH saturation adsorption, increasing from 2 mg/g to 11.7 mg/g. N-doped groups may enhance or inhibit adsorption, influenced by their specific electrostatic potentials. In contrast, O-doped groups provide stable and effective adsorption through their strong negative charges. Hierarchical pores facilitate NH transport and maximize the utilization of adsorption sites, substantially enhancing removal efficiency. Moreover, the micropore filling mechanism plays a pivotal role, especially in biochar with a high micropore concentration, further improving adsorption capacity. These findings deepen the understanding of adsorption mechanisms and underscore the potential of engineered biochar for effective ammonium recovery from wastewater, advancing environmental sustainability.
生物炭在去除废水中的铵（NH）方面显示出巨大潜力，有助于实现可持续的污染控制和养分回收。然而，优化生物炭结构仍然具有挑战性，特别是在孔隙结构、表面官能团和NH吸附机制之间的相互作用方面。本研究通过密度泛函理论（DFT）计算和分子动力学（MD）模拟，研究了NH在具有氮（N）和氧（O）掺杂基团以及分级孔隙的生物炭上的吸附机制，以应对这些挑战。结果表明，NH饱和吸附量显著提高，从2mg/g增加到11.7mg/g。N掺杂基团可能会增强或抑制吸附，这受到其特定静电势的影响。相比之下，O掺杂基团通过其强负电荷提供稳定而有效的吸附。分级孔隙促进了NH的传输，并使吸附位点的利用率最大化，从而显著提高了去除效率。此外，微孔填充机制起着关键作用，特别是在具有高微孔浓度的生物炭中，进一步提高了吸附能力。这些发现加深了对吸附机制的理解，并强调了工程生物炭从废水中有效回收铵的潜力，推动了环境可持续性发展。
