EDTAD-modified cassava stalks loaded with Fe3O4: highly efficient removal of Pb2+ and Zn2+ from aqueous solution

Environmental Science and Pollution Research - In this study, a novel magnetic cassava stalk composite (M-EMCS) was prepared through modification with ethylenediamine tetraacetic anhydride (EDTAD)...     

城市道路积尘PM 2.5碳组分春秋季节差异分析

为了解城市道路积尘PM 2.5中碳组分春秋季节差异,利用样方法采集石家庄市4种不同类型道路积尘PM 2.5样品,测定有机碳(OC)和元素碳(EC)浓度并分析。结果表明:OC,EC在积尘PM 2.5中平均浓度春季为86.77,12.11 mg/g,秋季为119.70,9.44 mg/g,秋季OC浓度大于春季,EC相反;OC/EC为6.4~7.9(春季)和11.36~17.49(秋季),存在严重的二次污染,秋季明显高于春季。与国内不同地区对比发现,石家庄市道路积尘中碳质颗粒物污染严重。主成分分析发现春季积尘中的碳主要来自于汽油车与柴油车尾气排放、道路降尘的沉积,而秋季则增加了生物质燃烧、燃煤排放的影响。     

多环芳烃对海洋贝类多生物水平毒性效应的研究进展

多环芳烃类化合物(PAHs)是海洋中常见的一类持久性有机污染物,对海洋生态安全及海洋生物健康造成严重威胁。海洋贝类作为海洋生态毒理学研究的模式生物,其滤食性、固着性等生理特点使其对PAHs具有较高的生物蓄积能力,可以在不同生物水平产生一系列的毒性效应。本文综述目前PAHs在海洋贝类多种生物水平所造成的生物毒性效应及其检测方法的研究进展,重点从个体生理特征、组织结构、细胞毒性和基因毒性4个层次展开讨论,为更有效地利用海洋贝类这一模型生物,深入开展PAHs对海洋生物的致毒效应与机制研究提供思路与检测方法参考。     

南京江北新区PM2.5中水溶性离子的季节特征和来源解析

为探究南京江北新区PM_2.5中水溶性离子的季节特征和来源，于2019年共采集了113个有效PM_2.5样品.用称重法和离子色谱法分别测定出PM_2.5和10种水溶性离子的质量浓度，并使用PMF源解析法对其进行来源解析.结果表明，观测期间南京江北新区PM_2.5和水溶性离子年平均浓度分别为（78.34±29.64）和（35.68±18.30）μg·m^-3，其四季变化趋势相同，冬季浓度高，夏季浓度低.10种水溶性离子中NO₃^-、SO₄^2-和NH₄⁺的浓度远远高于其他离子，其在总离子中的含量高达89.9%.南京江北新区四季PM_2.5中NH₄⁺主要与HSO₄^-和NO₃^-结合存在.硫氧化率（SOR）和氮氧化率（NOR）的年均值分别为0.53和0.28，说明观测期间大气中氮硫的二次生成率较高.南京江北新区PM_2.5中水溶性离子主要来源为二次转化、海盐和扬尘.     

Preparation of various thiol-functionalized carbon-based materials for enhanced removal of mercury from aqueous solution

In this work, biochar (BC), activated carbon (AC), and graphene oxide (GO) were thiol-functionalized using 3-mercaptopropyltrimethoxysilane (3-MPTS) (named as BCS, ACS, and GOS, respectively). BCS, ACS, and GOS were synthesized mainly via the interaction between hydrolyzed 3-MPTS and surface oxygen-containing functional groups (e.g., –OH, O–C=O, and C=O) and π-π interaction. The materials before and after modification were characterized and tested for mercury removal, including sorption kinetics and isotherms, the effects of adsorbent dosage, initial pH, and ionic strength. Pseudo-second-order sorption kinetic model (R² = 0.992~1.000) and Langmuir sorption isotherm model (R² = 0.964~0.998) fitted well with the sorption data of mercury. GOS had the most –SH groups with the largest adsorption capacity for Hg²⁺ and CH₃Hg⁺ (449.6 and 127.5 mg/g), followed by ACS (235.7 and 86.7 mg/g) and BCS (175.6 and 30.3 mg/g), which were much larger than GO (96.7 and 4.9 mg/g), AC (81.1 and 24.6 mg/g), and BC (95.6 and 9.4 mg/g). GOS and ACS showed stable mercury adsorption properties at a wide pH range (2~9) and ionic strength (0.01~0.1 mol/L). Mercury maybe removed by ligand exchange, surface complexation, and electrostatic attraction.

     

CaCu3Ti4O12, an efficient catalyst for ibuprofen removal by activation of peroxymonosulfate under visible-light irradiation

Environmental Chemistry Letters - Contamination of waters by pharmaceuticals is a major health issue. Therefore, there is a need for efficient techniques to remove pharmaceutical pollutants. Here,...     

沈阳环境空气臭氧浓度及累积速率时序曲线模拟研究

为了解环境空气臭氧累积规律,利用2017年沈阳市环境空气臭氧浓度数据,统计分析臭氧累积速率,并利用回归方法拟合并优化臭氧浓度及其累积速率的时间序列模型,同时结合气温、风力、臭氧前体物等时序变化情况分析臭氧浓度的影响因素。研究发现:沈阳市臭氧月均浓度年变化、日均浓度年变化以及小时浓度日变化时序曲线均呈现单峰形态;年变化中,6月的臭氧浓度最大,4月臭氧累积速率达到最大值;日变化中,14:00臭氧浓度达到最大值,09:00—11:00臭氧累积速率最大,19:00—20:00臭氧迅速消减。温度、风速同臭氧浓度之间均有较好的正相关性。臭氧前体物二氧化氮、挥发性有机物与臭氧浓度之间均呈明显的负相关性。     

Polycyclic aromatic hydrocarbons in river sediments from the western and southern catchments of the Bohai Sea, China: toxicity assessment and source identification

The concentration, distribution, and origin of 16 USEPA priority polycyclic aromatic hydrocarbons (PAHs) were investigated in river sediments from the western and southern catchments of the Bohai Sea, China. A toxicity assessment of 28 sediment samples collected from 15 main rivers was conducted by utilizing threshold and probable effect concentrations (TEC and PEC, respectively) derived from consensus-based sediment quality guidelines. The concentrations of total PAHs (∑PAH₁₆) ranged from 0.14 to 10,757 μg/kg dry weight (mean?=?1,368.6 μg/kg). The high concentrations of PAHs found in Binhai New Area of Tianjin and Binzhou City are likely the result of rapid population and heavy industry growth, resulting in elevated point and nonpoint source inputs of PAHs. Of the samples collected, samples 1 and 10 (7.1 % of the total) were categorized as toxic since some of the PAH concentrations exceeded the corresponding PECs. Twenty samples were classified as nontoxic, with both the individual PAH and the∑PAH₁₆ concentrations falling below the corresponding TECs. Analyses of selected PAH isomer ratios aided in the identification of PAH origins, allowing for a discrimination between pyrogenic and petrogenic sources. Spatial variability confirmed source heterogeneity within the study area. The most significant PAH-associated contamination was found in the Beitang River and Ji Canal, which are located in Binhai New Area. The magnitude of contamination and the likelihood of an ongoing influx of PAHs support the need for a better understanding of pollution sources and methods for both control and sediment restoration.     

Occurrence of veterinary antibiotics in animal wastewater and surface water around farms in Jiangsu Province, China

The objective of this investigation was to obtain a broad profile of veterinary antibiotics residues in animal wastewater and surface water around large-scale livestock and poultry farms in Jiangsu Province of China. Therefore, 53 samples collected from 27 large-scale animal farms in 11 cities and counties of Jiangsu Province in 2009, were monitored for 10 selected veterinary antibiotics using solid phase extraction and high performance liquid chromatography/electrospray ionization-tandem mass spectrometry (HPLC/ESI-MS/MS) techniques. Ten veterinary antibiotics were found in animal wastewaters, eight antibiotics were detected in pond waters, and animal farm-effluents and river water samples were contaminated by nine antibiotics. The most frequently detected antibiotics were sulfamethazine (75%), oxytetracycline (64%), tetracycline (60%), sulfadiazine (55%) and sulfamethoxazole (51%) which were detected with a maximum concentration of 211, 72.9, 10.3, 17.0 and 63.6 μg L⁻¹, respectively. The maximum concentration of 0.55 μg L⁻¹ for cyromazine, 3.67 μg L⁻¹ for chlortetracycline, 0.63 μg L⁻¹ for sulfadoxine, 39.5 μg L⁻¹ for doxycycline and 0.64 μg L⁻¹ for sulfaquinoxaline were determined in the collected samples. In general, the maximum concentration of the selected veterinary antibiotics was detected in animal wastewaters except for chlortetracycline in animal farm-effluents. In addition, residue levels of selected veterinary antibiotics in animal wastewater and surface water around the farms were related to animal species and have a high spatial variation.     

利用氢基质生物膜反应器去除水中砷酸盐

利用氢基质生物膜反应器(Hydrogen-based membrane biofilm reactor,MBfR)研究了NO_3~--N负荷、SO_4~(2-)负荷、As(Ⅴ)负荷、氢分压对水中砷去除效果的影响.结果表明,随着NO_3~--N进水负荷的增加,As(Ⅴ)和SO_4~(2-)还原受到明显抑制,系统产生As(Ⅲ)和NO_2~-的积累;随着SO_4~(2-)进水负荷的增加,反应器内总砷去除率由78.6%(25 mg·L-1SO_4~(2-))降低至1.1%(200 mg·L~(-1)SO_4~(2-)),而此时NO_3~--N的去除基本不受影响.同时,随着进水As(Ⅴ)负荷从0.25 mg·L~(-1)增至2 mg·L~(-1),出水SO_4~(2-)浓度明显升高,反应器内总砷去除率从70.0%降低至47.3%,而此时NO_3~--N的去除基本不受影响;当氢分压低于0.06 MPa时,提高氢分压可降低出水As(Ⅴ)浓度,当氢分压高于0.06 MPa后便不再是控制因素.由于体系中氢自养还原微生物会优先利用NO_3~--N和SO_4~(2-)作为电子受体,因此,为了保证As(Ⅴ)的高效还原去除,必须控制氢分压在0.05~0.07 MPa之间.