ZnO Nanopillar Coated Surfaces with Substrate‐Dependent Superbactericidal Property

ZnO nanopillars coated on various surfaces are able to kill adhered bacteria and fungi due to their physical structure through a rupturing mechanism. Remarkably, zinc foil and galvanized steel surfaces with ZnO nanopillar coatings demonstrate an excellent remote bacteria‐killing property. Their bacterial killing efficacy is several orders higher than ZnO nanopillars coated on other surfaces as well as ZnO nanoparticles themselves. Mechanistic study shows that the nanostructure surface kills adhered microbial cells by rupturing the cell wall, while superoxide (^?O₂^?) released from the ZnO coating with electrons donated from zinc via the Zn/ZnO interface rather than photoirritation is responsible for the superior remote killing. The results of this study represent a novel mechanism of surface disinfection and its application in water disinfection is also demonstrated.     

In Situ Disinfection through Photoinspired Radical Oxygen Species Storage and Thermal‐Triggered Release from Black Phosphorous with Strengthened Chemical Stability

Photodynamic therapy (PDT) utilizing light‐induced reactive oxygen species (ROS) is a promising alternative to combat antibiotic‐resistant bacteria and biofilm. However, the photosensitizer (PS)‐modified surface only exhibits antibacterial properties in the presence of light. It is known that extended photoirradiation may lead to phototoxicity and tissue hypoxia, which greatly limits PDT efficiency, while ambient pathogens also have the opportunity to attach to biorelevant surfaces in medical facilities without light. Here, an antimicrobial film composed of black phosphorus nanosheets (BPSs) and poly (4‐pyridonemethylstyrene) endoperoxide (PPMS‐EPO) to control the storage and release of ROS reversibly is introduced. BPS, as a biocompatible PS, can produce high singlet oxygen under the irradiation of visible light of 660 nm, which can be stably stored in PPMS‐EPO. The ROS can be gradually thermally released in the dark. In vitro antibacterial studies demonstrate that the PPMS‐EPO/BPS film exhibits a rapid disinfection ability with antibacterial rate of 99.3% against Escherichia coli and 99.2% against Staphylococcus aureus after 10 min of irradiation. Even without light, the corresponding antibacterial rate reaches 76.5% and 69.7%, respectively. In addition, incorporating PPMS significantly improves the chemical stability of the BPS.     

用于乡村公共卫生安全的多功能气调机

新冠疫情爆发揭示了世界范围内公共卫生安全领域存在的艰巨挑战,尤其是公共基础设施弱、公共卫生安全意识薄弱的乡村地区。本文面向乡村防疫的特性需求,基于气固吸附和固载二氧化氯技术,开发了一种兼具灭菌、驱虫和富碳施肥的新型气调机装置。机组采用四床变电吸附（ESA）碳捕集与变压吸附（PSA）制氮循环结合的方法,对CO2和N2进行富集;同时,将固载二氧化氯应用于吸附剂中,实现一定强度的杀菌效果。基于测试数据和模拟模型,对碳捕集循环中吸附和解吸温度的温差、制氮循环中出口流速和吸附压力对该气调机的分离性能（回收率、纯度、生产率）和能效性能（比能耗、最小分离功、第二定律效率）的影响进行分析。结果表明：CO2的回收率、纯度、生产率均随温差的增大而升高;N2的纯度随出口流速的增大而降低,随吸附压力的增大而升高;N2回收率和生产率随出口流速和吸附压力的升高均呈现上升的趋势;系统比能耗随吸附压力的升高而升高,随温差和出口流速的增大均呈现降低的趋势;第二定律效率呈现与比能耗相反的变化趋势。模拟结果显示：当温差为105 K,出口流速为0.01 m/s,吸附压力为1 MPa时,CO2和N2纯度均达到最大值,体积分数（VOL）分别为80.6% 和97.05%,此时系统比能耗为2.13 MJ/kg,第二定律效率为4.71%,能效性能处于较好水平;即使在其他操作条件下,CO2纯度普遍高于60%VOL,N2纯度普遍高于95%VOL,系统其他性能参数均可达到较高水平。     

基于TRIZ理论的公共扶手消毒装置设计

目的 解决目前公共扶手消毒设备自动化程度低且需要人力操作的问题.方法 首先对现有公共扶手消毒设备进行调研分析,找出存在的缺陷与问题;然后利用TRIZ理论中的功能分析、因果分析法进行分析,归纳出根本问题;最后利用物理矛盾、物场分析法、ARIZ算法工具找到问题的最终解,并形成最优解决方案.结果 运用TRIZ工具解决问题,设计出一款能够自主通过公共扶手上的障碍部分,实现无接触式全自动公共扶手消毒设备.结论 方案解决了目前公共扶手消毒设备存在的诸多问题,为TRIZ理论在解决实际问题中的应用提供思路和参考.     

紫外线在饮用水生产中的应用

紫外线是光谱介于可见光的紫色光和x射线之间的光波。在饮用水生产中用于消毒杀菌有较大的优越性 ,紫外线还可在饮用水生产中用于降解有机物 ,在反渗透膜前加装紫外线装置可保护膜体 ,延长膜的使用寿命     

氯/二氧化氯消毒对热水管壁生物膜的控制作用

建筑生活热水存在严重的生物安全性问题,需要采取必要的消毒措施.为此,采用建筑生活热水模拟管道系统,对比研究氯或二氧化氯冲击消毒对管壁生物膜微生物的灭活效果,并通过高通量测序和扫描电子显微镜评估冲击消毒对管壁生物膜群落组成和生物膜表观特征的影响.结果表明,高消毒剂质量浓度可显著提高微生物的灭活速率,但已不能进一步改善微生物灭活率; 1. 5 mg/L氯或二氧化氯的消毒效果不佳; 3～5 mg/L氯或二氧化氯在冲击消毒120 min后,总大肠菌群、细菌总数和异养菌(HPC)均可达到完全灭活的程度,能够有效控制热水管道生物膜,说明足够的消毒剂质量浓度和消毒时间对保持高效灭活率非常必要.生活热水管壁生物膜的微生物多样性丰富,异常球菌-栖热菌门和变形菌门为优势门,并含有多种致病菌,与市政供水和二次供水管道系统的优势菌群有很大差异;氯或二氧化氯冲击消毒对各种菌门均有不同程度的灭活效果,二氧化氯对致病菌、变形菌门和衣原体门等的灭活效果更佳.氯或二氧化氯冲击消毒能有效破坏生物膜的表面结构,使生物膜出现间隙变大、萎缩、脱落等现象,二氧化氯对生物膜的破坏作用更显著,具有更佳的冲击消毒作用和消毒效果.研究结果为建筑生活热水系统的安全消毒技术以及生物安全性保障提供了支持.     

Theoretical and Experimental Insight into the Mechanism for Spontaneous Vertical Growth of ReS2 Nanosheets

Rhenium disulfide (ReS₂) differs fundamentally from other group‐VI transition metal dichalcogenides (TMDs) due to its low structural symmetry, which results in its optical and electrical anisotropy. Although vertical growth is observed in some TMDs under special growth conditions, vertical growth in ReS₂ is very different in that it is highly spontaneous and substrate‐independent. In this study, the mechanism that underpins the thermodynamically favorable vertical growth mode of ReS₂ is uncovered. It is found that the governing mechanism for ReS₂ growth involves two distinct stages. In the first stage, ReS₂ grows parallel to the growth substrate, consistent with conventional TMD growth. However, subsequent vertical growth is nucleated at points on the lattice where Re atoms are “pinched” together. At such sites, an additional Re atom binds with the cluster of pinched Re atoms, leaving an under‐coordinated S atom protruding out of the ReS₂ plane. This under‐coordinated S is “reactive” and binds to free Re and S atoms, initiating growth in a direction perpendicular to the ReS₂ surface. The utility of such vertical ReS₂ arrays in applications where high surface‐to‐volume ratio and electric‐field enhancement are essential, such as surface enhanced Raman spectroscopy, field emission, and solar‐based disinfection of bacteria, is demonstrated.     

饮用水消毒副产物生物毒性与调控策略的研究

饮用水消毒可以有效除去病毒、细菌等有害微生物,但消毒剂会与水中的有机物反应生成多种消毒副产物(DBPs),危害人类健康。基于对消毒副产物种类、生成及污染现状的探讨,归纳总结了DBPs的典型生物毒性及其毒性作用机制。为有效防控DBPs环境风险,深入探讨了针对去除DBPs前体物、优化消毒剂及消毒过程、DBPs毒性的调控策略。最后对DBPs生物毒性作用机制及调控策略的研究进行了展望,为DBPs污染防治提供理论与技术支持。     

污水氯消毒过程中有机氯胺的生成及其影响

消毒是保证污水再生利用水质安全的必要措施，氯消毒是最常用的消毒方法。在氯消毒过程中，污水中的含氮有机物与氯反应会生成有毒有害的有机氯胺。国外很早就开始了对有机氯胺的研究，而国内对有机氯胺的关注较少。有机氯胺在一定条件下可以在自然水体中长时间稳定存在，部分有机氯胺在脱氯时不易被亚硫酸钠脱除。有机氯胺一般具有一定的生物毒性，而且一些有机氯胺也是致癌消毒副产物的前体物质，对水中的生物以及人体健康会产生毒害作用。消毒过程中有机氯胺的生成不仅会降低消毒效果，而且也会影响水体中余氯的测定。