The production of cheap, efficient, and stable photocatalysts for degrading antibiotic contaminants remains challenging. Herein, Bi2O3/boron nitride (BN)/Co3O4 ternary composites were synthesized using the impregnation method. The morphological characteristics, structural features, and photochemical properties of the prepared photocatalysts were investigated via X-ray diffraction, Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, high-resolution transmission electron microscopy, and ultraviolet–visible (Vis) diffuse reflectance spectrum techniques. BN was used as a charge transfer bridge in the ternary composites, which afforded a heterojunction between the two semiconductors. The formation of the heterojunction substantially enhanced the charge separation and improved the photocatalyst performance. The degradation activity of the Bi2O3/BN/Co3O4 ternary composites against norfloxacin (NOR) under Vis light irradiation was investigated. The degradation rate of NOR using 5-wt% Bi2O3/BN/Co3O4 reached 98% in 180 min, indicating excellent photocatalytic performance. The ternary composites also exhibited high photostability with a degradation efficiency of 88.4% after five cycles. Hydroxyl radicals (•OH), superoxide radicals (•O2−), and holes (h+) played a synergistic role in the photocatalytic reaction, where h+ and •O2− were more important than •OH. Consequently, seven intermediates and major photocatalytic degradation pathways were identified. Toxicity experiments showed that the toxicity of the degradation solution to Chlorella pyrenoidosa decreased. Finally, the ecotoxicity of NOR and its intermediates were analyzed using the Toxicity Estimation Software Tool, with most intermediates exhibiting low toxicity.

The production of cheap, efficient, and stable photocatalysts for degrading antibiotic contaminants remains challenging. Herein, Bi2O3/boron nitride (BN)/Co3O4 ternary composites were synthesized using the impregnation method. The morphological characteristics, structural features, and photochemical properties of the prepared photocatalysts were investigated via X-ray diffraction, Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, high-resolution transmission electron microscopy, and ultraviolet-visible (Vis) diffuse reflectance spectrum techniques. BN was used as a charge transfer bridge in the ternary composites, which afforded a heterojunction between the two semiconductors. The formation of the heterojunction substantially enhanced the charge separation and improved the photocatalyst performance. The degradation activity of the Bi2O3/BN/Co3O4 ternary composites against norfloxacin (NOR) under Vis light irradiation was investigated. The degradation rate of NOR using 5-wt% Bi2O3/BN/Co3O4 reached 98% in 180 min, indicating excellent photocatalytic performance. The ternary composites also exhibited high photostability with a degradation efficiency of 88.4% after five cycles. Hydroxyl radicals (•OH), superoxide radicals (•O2-), and holes (h+) played a synergistic role in the photocatalytic reaction, where h+ and •O2- were more important than •OH. Consequently, seven intermediates and major photocatalytic degradation pathways were identified. Toxicity experiments showed that the toxicity of the degradation solution to Chlorella pyrenoidosa decreased. Finally, the ecotoxicity of NOR and its intermediates were analyzed using the Toxicity Estimation Software Tool, with most intermediates exhibiting low toxicity.

Near-ground ozone in the Yangtze River Delta (YRD) region has become one of the main air pollutants that threaten the health of residents. However, to date, the transport behavior and source areas of ozone in the YRD region have not been systematically analyzed. In this study, by combining the ozone observational record with a HYSPLIT (hybrid single-particle Lagrangian integrated trajectory) model, we tried to reveal the spatiotemporal regularity of the airflow transport trajectory of ozone. Spatially, high ozone concentrations mainly clustered in industrial cities and resource-based cities. Temporally, the center of the ozone pollution shifted westward of Nanjing from 2015 to 2021. With the passage of time, the influence of meteorological elements on the ozone concentration in the YRD region gradually weakened. Marine atmosphere had the most significant impact on the transmission path of ozone in Shanghai, of which the trajectory frequency in 2021 accounted for 64.21% of the total frequency. The transmission trajectory of ozone in summer was different from that in other seasons, and its transmission trajectory was mainly composed of four medium-distance transmission paths: North China-Bohai Sea, East China Sea-West Pacific Ocean, Philippine Sea, and South China Sea-South China. The contribution source areas mainly shifted to the southeast, and the emission of pollutants from the Shandong Peninsula, the Korean Peninsula-Japan, and the Philippine Sea-Taiwan area increased the impact of ozone pollution in the Shanghai area from 2019 to 2021. This study identified the regional transport path of ozone in the YRD region and provided a scientific reference for the joint prevention and control of ozone pollution in this area.

Antibiotics have attracted widespread attention around the world because they are ubiquitous in the environment and can lead to antibiotic-resistant microbes developing and pose ecotoxicological risks. In this study, we determined the spatiotemporal distributions of 39 antibiotics in 19 drinking water sources in Jiangsu area of the lower Yangtze River and attempted to identify the sources of the antibiotics and to prioritize the antibiotics. The total antibiotic concentrations in spring and fall were 234.56-6515.99 and 151.12-2562.59 ng/L, respectively. In spring, the total antibiotic concentration gradually increased from upstream to downstream. In fall, the antibiotic concentration did not markedly vary upstream to downstream (total concentrations 151.12-432.17 ng/L) excluding site S9 and S10. Analysis using a positive matrix factorization (PMF) model indicated that the antibiotics had four main sources. Pharmaceutical wastewater was the main source, contributing 34.1% and 41.2% of total antibiotics in spring and fall, respectively, and domestic wastewater was the second most important source, contributing 24.4% and 43% of total antibiotics in spring and fall, respectively. Pharmaceutical wastewater was the main source from midstream to downstream, but the other sources made different contributions in different areas because of the various ranges of human activities. An ecological risk assessment was performed. Stronger risks were posed by antibiotics in spring than fall, and fluoroquinolone antibiotics posed the strongest risks. Optimized risk quotients indicated that norfloxacin was a high-risk contaminant. An assessment of the risk of resistance development indicated that norfloxacin, ciprofloxacin, and enrofloxacin posed moderate to high risks of resistance development and should be prioritized for risk management. The results of this study are important reference data for identifying key sources of antibiotics and developing strategies to manage antibiotic contamination in similar areas.

以含锌废盐酸为原料制备磷酸锌[Zn3(PO4)2],探讨含锌废盐酸中Zn、Fe、Cr、Ni等重金属质量分数、TOC质量浓度、磷酸体积分数和反应时间等典型因素对Zn3(PO4)2纯度及化学组成结构的影响,并用XRD及SEM表征Zn3(PO4)2的物相结构.结果表明,含锌废盐酸可制备纯度较高、结构较为稳定的Zn3(PO4)2产品,制备过程中废盐酸中的Fe对Zn3(PO4)2产出纯度的影响较大;Zn3(PO4)2的产出纯度随TOC质量浓度的升高而下降;当磷酸体积分数低于85％时,对Zn3(PO4)2产出纯度总体呈正相关趋势,而高于85％后,产出纯度则有所降低;反应时间为5 h时制备Zn3(PO4)2的效率最高.

焚烧是城市生活垃圾减量化的重要处置方式,随之产生的焚烧飞灰问题也日益严重.高温熔融技术可以有效固化焚烧飞灰中的重金属,并深度分解二噁英.介绍了国内外焚烧飞灰高温熔融制备微晶玻璃技术的现状和研究进展,着重探讨了添加剂、预处理、热处理和后处理工艺对微晶玻璃品质的影响.

概述了中国长三角地区一般工业固体废物的产生、处置及综合利用现状,围绕一般工业固体废物实际处置效率不高,区域利用处置能力不平衡,配套利用处置污染控制标准缺失,污染环境案件频发等问题,梳理并分析其主要原因.以废弃矿山为突破口,为长三角地区一般工业固体废物的区域协同处置、污染环境防治与管理提供新的思路.

Nano ferrous sulfide (n-FeS) colloids show an excellent performance in the application of remediation in situ soil and groundwater. However, due to the interfacial effect and high reactivity of the nano sized FeS, n-FeS easy to agglomerate, which reduces their remediation efficiency. In this study, a novel composite colloid was synthesized using polyacrylic acid salt (PAA) and n-FeS. The PAA-n-FeS colloid was used to remove Cr(VI) in water remediation, and its removal mechanism and efficiency were explored. The results showed that the hydrodynamic diameter of PAA-n-FeS ranged from 65.04-90.09 nm and the zeta potential was from -27 to -54 mV at pH varying from 4.5-9.0. PAA was coated on the surface of n-FeS, which improved the dispersibility and stability of n-FeS by increasing the steric hindrance and electrostatic repulsion between n-FeS particles. Moreover, the Cr (VI) maximum removal amount PAA-n-FeS was 432.79 mg/g, which was significantly higher than that of n-FeS (218.29 mg/g) and PAA (12.32 mg/g). The mechanism of PAA-n-FeS removal of Cr(VI) was mainly derived from its own reducibility. The reaction products were mainly Cr(OH)(3), Cr(III)-Fe(III), Cr2O3, and Cr2S3. This research not only finds a new stabilizer for preventing n-FeS agglomeration, but also provides a novel n-FeS composited colloid for promoting the practical application to Cr(VI) removal from water.

Iohexol (IOH), as a typical iodinated X-ray contrastmedia (ICMs) with potential threat to human health, is difficult to be removed with the conventional wastewater treatment methods. In this work, new boron nitride coupled Bi2MoO6 layered microspheres (BN/Bi2MoO6) composites were applied to remove IOH from water via photocatalytic degradation. The degradation constant k(app) of IOH over 3.5 wt% BN/Bi2MoO6 was 0.016 min(-1), which was 3.2 times that of Bi2MoO6 (0.005 min(-1)). The degradation rate of IOH on 3.5wt% BN/Bi2MoO6 reached 92% in 150 min. The enhanced photocatalytic activity of BN/Bi2MoO6 can be attributed to the heterojunction between BN and Bi2MoO6. The matched type-I band alignment heterojunction of two semiconductors prominently improved the charge separation. Based on the trapping experiments, holes and superoxide radicals were proved to be the main active species for photocatalytic IOH degradation. Besides, the degradation products of IOH were analyzed by LC-HRMS and the possible degradation mechanism of IOH was also proposed in this work. (C) 2020 Elsevier B.V. All rights reserved.

Characteristics of the spatial and temporal distribution of air pollutants may reveal the cause of air pollution, especially for large regions where the anthropogenic pollutant emission is concentrated. This study addresses this issue by focusing on Shandong province, which has the highest air pollutant emissions in China. First, the spatial and temporal variation characteristics of the observed concentrations of conventional pollutants are analyzed in detail. The most prominent indicator of the problem (PM2.5), was selected as the key analytical object. On the spatial scale, the Multivariate Moran model was used to identify factors affecting the spatial distribution of PM2.5. On the time scale, wavelet analysis was used to explore the fluctuation characteristics of PM2.5 at different time periods. Results show that there are significant regional differences in pollutant concentration within Shandong province. The concentration of particulate matter and gaseous pollutants in western and northern Shandong is significantly higher than eastern Shandong. The average concentrations of PM2.5, PM10, SO2 and NO2 were highest in winter and lowest in summer, whereas concentration of O3 peaked in summer. For PM2.5, the annual mean concentration has a significant spatial correlation with SO2 emission, GDP per capita, population density and energy consumption per unit of GDP; in addition, the correlation between different regions and various indices is different. On the time scale, the fluctuation energy of PM2.5 concentrated in Dezhou and Liaocheng is the strongest on December 18 and 19, 2015. The inversion temperature has a strong influence on the daily variation of PM2.5 concentration. The formation and evolution of atmospheric pollution, therefore, can be explored by combining the temporal and spatial distribution of pollutants, providing a comprehensive analytical method for atmospheric pollution in different regions.

The adsorption of roxarsone (ROX) on the humic acid modified goethite (HA-alpha-FeOOH) was evaluated for several potential environmental factors. Results showed that 1) ROX had a higher adsorption capacity onto HA-alpha-FeOOH than unmodified alpha-FeOOH; 2) the adsorption of ROX increased with a decrease in pH; 3) the high ionic strength significantly inhibited the adsorption capacity of HA-alpha-FeOOH; and 4) a higher temperature yielded greater adsorption, since the process for ROX to be adsorbed by HA-alpha-FeOOH was a spontaneous endothermic reaction. The maximum adsorption capacity of ROX was found to be 80.71 mg center dot g(-1), when the temperature was 308 K. Meanwhile, the inhibitory effects of ionic strength and PO43- on the adsorption of ROX onto HA-alpha-FeOOH were enhanced with an increase in concentration. In addition, the adsorption equilibrium data obeyed Langmuir isotherm model and the kinetic data were well described by the pseudo-second-order kinetic model. From the infrared spectra of HA-alpha-FeOOH, it could be deduced that the ROX adsorption onto HA-alpha-FeOOH was achieved via the ion exchange between the arsenic acid and the carboxyl group on adsorbent, as well as the formation of As-O-Fe bond between Fe-O and arsenic acid ions.