State Key Laboratory of Urban Water Resource and Environment (SKLUWRE), School of Environment, Harbin Institute of Technology, 73 Huanghe Road, Nangang District 150090, Harbin, PR China.
State Key Laboratory of Urban Water Resource and Environment (SKLUWRE), School of Environment, Harbin Institute of Technology, 73 Huanghe Road, Nangang District 150090, Harbin, PR China.
Water Res. 2024 Aug 1;259:121834. doi: 10.1016/j.watres.2024.121834. Epub 2024 May 23.
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.
广泛爆发的未知病原体威胁性感染和水传播感染，催生了用于病原体消除的吸附方法的发展。我们提出了一种涉及ε-聚赖氨酸（PLL）的生物炭功能化策略，PLL 是一种具有可变折叠构象的生物大分子聚（氨基酸），可作为生物炭上的“病原体夹具”。PLL 通过聚多巴胺（PDA）交联成功桥接到生物炭上。PLL 内正电荷侧链的延伸能够捕获水中的纳米级病毒和微米级细菌，实现了优异的去除性能。这种功能化生物炭被初步纳入超滤（UF）系统，以实现对病原体的有效和可控吸附和保留，并实现病原体从膜表面/孔转移到生物炭表面以及冲洗水。添加生物炭的 UF 系统对病原体表现出完全保留（约 7 个对数减少值）和水力洗脱到膜冲洗水中。观察到对有机物去除和抗污染能力的改善，表明在 UF 病原体去除方面打破了对不可逆污染的依赖的权衡。化学特性揭示了包含静电/疏水相互作用、孔填充、电子转移、化学键和二级结构转变的吸附机制。微观和机械分析验证了快速吸附和病原体裂解的机制。用于使用后的生物炭再生的低浓度碱性溶液，促进 PLL 侧链去质子化和折叠结构（α-螺旋/β-折叠）的转变。生物炭再生过程还促进了病原体的有效脱离/失活以及生物炭上功能基团的保护，这得到了物理化学检查和分子动力学模拟的证实。作为动态臂的聚（氨基酸）的可折叠性，显著促进了病原体的捕获/解吸/失活和生物炭的再生。这项研究还为在不同压力、温度、进料中的活性氧种类和化学清洗溶液下，由聚（氨基酸）功能化生物炭改性的 UF 系统的性能研究提供了启示，对公共卫生、生物炭的环境应用和 UF 过程的改进具有深远的意义。
