One-pot hydrothermal fabrication of BiVO4/Fe3O4/rGO composite photocatalyst for the simulated solar light-driven degradation of Rhodamine B

• BiVO₄/Fe₃O₄/rGO has excellent photocatalytic activity under solar light radiation. • It can be easily separated and collected from water in an external magnetic field. • BiVO₄/Fe₃O₄/0.5% rGO exhibited the highest RhB removal efficiency of over 99%. • Hole (h⁺) and superoxide radical (O₂^•−) dominate RhB photo-decomposition process. • The reusability of this composite was confirmed by five successive recycling runs. Fabrication of easily recyclable photocatalyst with excellent photocatalytic activity for degradation of organic pollutants in wastewater is highly desirable for practical application. In this study, a novel ternary magnetic photocatalyst BiVO₄/Fe₃O₄/reduced graphene oxide (BiVO₄/Fe₃O₄/rGO) was synthesized via a facile hydrothermal strategy. The BiVO₄/Fe₃O₄ with 0.5 wt% of rGO (BiVO₄/Fe₃O₄/0.5% rGO) exhibited superior activity, degrading greater than 99% Rhodamine B (RhB) after 120 min solar light radiation. The surface morphology and chemical composition of BiVO₄/Fe₃O₄/rGO were studied by scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, UV–visible diffuse reflectance spectroscopy, Fourier transform infrared spectroscopy, and Raman spectroscopy. The free radicals scavenging experiments demonstrated that hole (h⁺) and superoxide radical (O₂^•−) were the dominant species for RhB degradation over BiVO₄/Fe₃O₄/rGO under solar light. The reusability of this composite catalyst was also investigated after five successive runs under an external magnetic field. The BiVO₄/Fe₃O₄/rGO composite was easily separated, and the recycled catalyst retained high photocatalytic activity. This study demonstrates that catalyst BiVO₄/Fe₃O₄/rGO possessed high dye removal efficiency in water treatment with excellent recyclability from water after use. The current study provides a possibility for more practical and sustainable photocatalytic process.     

测定化学物对乙酰胆碱酯酶抑制毒性的微板吸光法研究

随着化学污染物种类与数量的日益增多,高通量测试方法显得越来越重要。基于乙酰胆碱酯酶(ACh E)抑制法原理,以多功能酶标仪为测试设备,96孔微板为暴露反应载体,建立了测定化学物对ACh E抑制毒性的微板吸光法。系统研究了ACh E浓度、碘化硫代乙酰胆碱(ATCI)浓度、二硫代二硝基苯甲酸(DTNB)浓度对显色吸光度、吸光度变化速率、化学物测试毒性的影响。结果表明,随着ACh E、DTNB、ATCI的浓度增加,吸光度均增加;吸光度变化速率与ACh E浓度呈正相关,与DTNB浓度基本无关,与ATCI浓度呈现先增后减的双相关系;随着ATCI浓度增加,灭多威剂量-效应曲线(DRC)向右移动。最终建立的优化测试条件为DTNB 0.2 g·L~(-1)、ATCI 0.2 g·L~(-1)、ACh E 0.04 U·m L~(-1)、p H 6.8、反应温度29℃及暴露时间15 min;并与国标方法进行了对比与验证,发现试剂加样顺序对毒性测定结果有显著影响。基于ACh E的微板毒性测试结果表明,灭多威的DRC呈现良好的S型曲线,可用Weibull函数有效表征,拟合决定系数R2大于0.97,空白变异控制在了±10%以内。此方法可用于化学污染物的高通量毒性检测。     

Combined effects of air pollution in adulthood and famine exposure in early life on type 2 diabetes

Environmental Science and Pollution Research - Famine exposure or air pollution is linked to type 2 diabetes mellitus (T2DM). However, their combined effects on T2DM remain largely unknown. A total...     

石家庄市夏季臭氧污染近地层垂直变化特征

基于2022年6月1日—8月31日河北省石家庄市地面气象要素和臭氧（O₃）观测数据，结合O₃激光雷达垂直探测数据分析近地层O₃垂直变化特征，并利用后向轨迹聚类分析法探讨其污染来源。结果表明：（1）2022年夏季石家庄O₃污染天数为6月＞7月＞8月。影响ρ（O₃）变化的主要影响因子是气温，平均气温与ρ（O₃）正相关，相对湿度与ρ（O₃）负相关。（2）当探测高度≥2 km时，全天、日间、夜间的ρ（O₃）变化较稳定，ρ（O₃）均在100μg/m³左右。近地层ρ（O₃）差异最大，无论是日间还是夜间，ρ（O₃）均在0.3 km左右达到峰值，之后逐渐降低。6月的ρ（O₃）垂直变化速率较大，7、8月ρ（O₃）垂直变化速率逐渐降低。（3）不同垂直高度下，石家庄夏季ρ（O₃）日变化情况均成“单峰单谷”型，地面ρ（O₃）日变化波动最明显，随着高度的上升ρ（O₃）日变化情况趋于平缓。（4）后向轨迹聚类分析结果表明，距离地面10，500，1 000 m高度层的O₃后向轨迹均呈散射状分布，距离地面10 m的O₃路径来源为河北西南部，距离地面500 m的O₃路径来源为河北南部，距离地面1 000 m的O₃主要途经地点为内蒙古西南部、西北部和河北东北部。     

利用流式影像术(FlowCAM)分析淡水浮游藻类群落特征 ——以北京城区主要河流为例

浮游藻类是水生态系统的重要初级生产者,对其进行分类鉴定和定量分析是开展生态研究的基础.选取北京城区主要河流为研究对象,于2020年6—7月(夏季)、10月(秋季)对北运河水系22个站位的表层水进行采样调查,探究利用流式影像术(FlowCAM)分析浮游藻类群落结构的可行性.结果表明,浮游藻类的细胞丰度和粒径组成均存在着明...     

Effects of tetracycline on the secondary metabolites and nutritional value of oilseed rape (Brassica napus L.)

Environmental Science and Pollution Research - Secondary metabolism, which helps a plant cope with external stress, is sensitive to environmental changes and plays a prominent role in maintaining...     

Construction of MoS2 nanoarrays and MoO3 nanobelts: Two efficient adsorbents for removal of Pb（Ⅱ）, Au（Ⅲ） and Methylene Blue

Toxic heavy metal ions, valuable noble metal ions and organic dyes are significant concerns in wastewater treatment. In this work, MoO₃ nanobelts（MoO₃ NBs） prepared by solvothermal method and MoS₂ nanoarrays（Mo S₂ NAs） constructed using MoO₃NBs precursor were proposed to effectively remove heavy/noble metal ions and organic dyes, such as Pb^（Ⅱ）, Au^（Ⅲ）and Methylene Blue（MB）. The two adsorbents exhibited the excellent adso...