Microplastics enhance the adsorption capacity of zinc oxide nanoparticles:Interactive mechanisms and influence factors

Microplastics(MPs)are of particular concern due to their ubiquitous occurrence and propen-sity to interact and concentrate various waterborne contaminants from aqueous surround-ings.Studies on the interaction and joint toxicity of MPs on engineered nanoparticles(ENPs)are exhaustive,but limited research on the effect of MPs on the properties of ENPs in multi-solute systems.Here,the effect of MPs on adsorption ability of ENPs to antibiotics was in-vestigated for the first time.The results demonstrated that MPs enhanced the adsorption affinity of ENPs to antibiotics and MPs before and after aging showed different effects on ENPs.Aged polyamide prevented aggregation of ZnONPs by introducing negative charges,whereas virgin polyamide affected ZnONPs with the help of electrostatic attraction.FT-IR and XPS analyses were used to probe the physicochemical interactions between ENPs and MPs.The results showed no chemical interaction and electrostatic interaction was the dom-inant force between them.Furthermore,the adsorption rate of antibiotics positively corre-lated with pH and humic acid but exhibited a negative correlation with ionic strength.Our study highlights that ENPs are highly capable of accumulating and transporting antibiotics in the presence of MPs,which could result in a widespread distribution of antibiotics and an expansion of their environmental risks and toxic effects on biota.It also improves our understanding of the mutual interaction of various co-existing contaminants in aqueous environments.     

纳米银颗粒在水环境中的环境行为和毒性效应研究进展

纳米材料的环境行为和生态效应是目前国内外研究的热点,其中纳米银颗粒(Ag NPs)是使用量最高的纳米材料。本文主要总结了Ag NPs在水环境中的赋存、Ag NPs的环境行为、Ag NPs对不同种类微生物的毒性效应以及影响Ag NPs毒性效应的因素,最后对Ag NPs在河口区的研究进行了展望。     

Ag插层K4Nb6OO17复合光催化剂降解水中有机污染物

介绍了通过微波辅助的离子交换法制备Ag插层K₄N_6OO₁₇复合光催化剂。复合光催化剂在降解水体中亚甲基蓝的过程中呈现出很高的光催化活性,并且插层复合光催化剂对亚基蓝在碱性条件下能发挥更高效的降解作用且对不同初始浓度的亚甲基蓝均具有较好的移除降解效率。在相同的反应条件下,Ag插层复合光催化剂要比等量的Ag负载K₄N_6OO₁₇,Ag负载TiO₂复合光催化剂活性高很多,使Ag插层K₄N_6OO₁₇复合光催化剂在净化水体污染物方面表现出更显著的优势。     

钯掺杂的TiO2纳米线阵列@MoS2电极光电催化高效还原六价铬和同步氧化对氯苯酚的机理研究

采用电沉积法将高分散的Pd纳米颗粒引入到TiO₂纳米线阵列@MoS₂（TNA@MoS₂）电极表面,并用于光阴极同步还原六价铬（Cr（VI））和氧化对氯苯酚（4-CP）.同时,通过X射线衍射、扫描电子显微镜和漫反射光谱对TNA@MoS₂/Pd电极进行了表征.光电催化实验表明,TNA@MoS₂/Pd光阴极在30 min内对Cr（VI）的还原效率达到99.8%,对4-CP的氧化效率达到91.5%且矿化效率为58.4%.循环伏安、电子自旋共振光谱、荧光光谱和自由基淬灭实验证实了同步还原和氧化反应的关键活性物种和作用机理.结果表明,TNA@MoS₂/Pd光阴极产生的稳定的原子氢（H*）,不仅可快速还原Cr（VI）,而且与溶解的O₂结合产生H₂O₂,提高了?OH的产量,从而同步氧化4-CP.循环实验表明,TNA@MoS₂/Pd电极具有良好的可重复使用性.     

Do geomagnetic storms change the behaviour of the stingless bee guiruçu (Schwarziana quadripunctata)?

Six behavioural experiments were carried out to investigate the magnetic field effects on the nest-exiting flight directions of the honeybee Schwarziana quadripunctata (Meliponini). No significant differences resulted during six experiment days under varying geomagnetic field and the applied static inhomogeneous field (about ten times the geomagnetic field) conditions. A surprising statistically significant response was obtained on a unique magnetic storm day. The magnetic nanoparticles in these bees, revealed by ferromagnetic resonance, could be involved in the observed effect of the geomagnetic storm.