Abstract：
Widespread outbreaks of threatening infections caused by unknown pathogens and water transmission have spawned the development of adsorption methods for pathogen elimination. We proposed a biochar functionalization strategy involving ε-polylysine (PLL), a bio-macromolecular poly(amino acid)s with variable folding conformations, as a \"pathogen gripper\" on biochar. PLL was successfully bridged onto biochar via polydopamine (PDA) crosslinking. The extension of electropositive side chains within PLL enables the capture of both nanoscale viruses and micrometer-scale bacteria in water, achieving excellent removal performances. This functionalized biochar was tentatively incorporated into ultrafiltration (UF) system, to achieve effective and controllable adsorption and retention of pathogens, and to realize the transfer of pathogens from membrane surface/pore to biochar surface as well as flushing water. The biochar-amended UF systems presents complete retention (∼7 LRV) and hydraulic elution of pathogens into membrane flushing water. Improvements in removal of organics and anti-fouling capability were observed, indicating the broken trade-off in UF pathogen removal dependent on irreversible fouling. Chemical characterizations revealed adsorption mechanisms encompassing electrostatic/hydrophobic interactions, pore filling, electron transfer, chemical bonding and secondary structure transitions. Microscopic and mechanical analyses validated the mechanisms for rapid adsorption and pathogen lysis. Low-concentration alkaline solution for used biochar regeneration, facilitated the deprotonation and transformation of PLL side chain to folded structures (α-helix/β-sheet). Biochar regeneration process also promoted the effective detachment/inactivation of pathogens and protection of functional groups on biochar, corroborated by physicochemical inspection and molecular dynamics simulation. The foldability of poly(amino acid)s acting like dynamic arms, significantly contributed to pathogen capture/desorption/inactivation and biochar regeneration. This study also inspires future investigation for performances of UF systems amended by poly(amino acid)s-functionalized biochar under diverse pressure, temperature, reactive oxygen species of feeds and chemical cleaning solutions, with far-reaching implications for public health, environmental applications of biochar, and UF process improvement.
摘要：
由未知病原体和水传播引起的威胁性感染的广泛爆发催生了用于消除病原体的吸附方法的发展。我们提出了一种涉及ε-聚赖氨酸（PLL）的生物炭功能化策略，具有可变折叠构象的生物大分子聚(氨基酸)，作为生物炭上的“病原体夹持器”。PLL通过聚多巴胺（PDA）交联成功地桥接到生物炭上。PLL内正电侧链的延伸使得能够捕获水中的纳米级病毒和微米级细菌。实现优异的去除性能。将这种功能化的生物炭暂时掺入超滤（UF）系统中，实现病原体的有效和可控的吸附和保留，并实现病原体从膜表面/孔转移到生物炭表面以及冲洗水。生物炭改良的UF系统具有完全保留（〜7LRV）和将病原体水力洗脱到膜冲洗水中。观察到有机物去除和防污能力的改善，表明UF病原体去除的折衷取决于不可逆的结垢。化学表征揭示了包含静电/疏水相互作用的吸附机制，孔隙充填,电子转移,化学键合和二级结构转变。微观和机械分析验证了快速吸附和病原体裂解的机制。低浓度碱性溶液用于生物炭再生，促进PLL侧链向折叠结构(α-螺旋/β-折叠)的去质子化和转化。生物炭再生过程还促进了病原体的有效分离/失活和生物炭上官能团的保护。通过物理化学检查和分子动力学模拟得到证实。聚(氨基酸)的可折叠性像动态臂一样，显着有助于病原体捕获/解吸/灭活和生物炭再生。这项研究还启发了未来的研究，研究了在不同压力下通过聚（氨基酸）s官能化生物炭修改的UF系统的性能，温度,进料和化学清洁溶液的活性氧，对公共卫生有着深远的影响，生物炭的环境应用，和UF工艺改进。
