微波辅助法合成纳米ReFeO3光催化剂

以稀土金属硝酸盐La(NO₃)₃、Sm(NO₃)₃、Eu(NO₃)₃、Gd(NO₃)₃和Fe(NO₃)₃·9H₂O为原材料, 以活性炭为模板剂,聚乙烯醇(PVA)和尿素分别用作阻聚剂和均相沉淀剂,在微波辐照下制得纳米钙钛矿型化合物ReFeO₃(Re:La,Sm,Eu,Gd)。用X射线粉末衍射仪(XRD)、UV-vis漫反射仪(DRS)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)对产物组成、结构、颗粒大小、形貌等进行了表征,结果表明产物均为单一钙钛矿结构的纳米颗粒。以产物为光催化剂,在可见光照射下对罗丹明B水溶液进行光催化降解实验,发现该类化合物均具有较好的光催化活性,180 min内对罗丹明B的脱色率均达到85%以上。     

CNQDs/Ag3PO4/g-C3N4复合光催化材料的制备及其对双酚A的降解性能

采用溶剂热法和原位沉淀法制备了CNQDs/Ag3PO4/g-C3N4三元复合光催化剂,通过SEM、TEM、XRD、FT-IR、XPS、BET等手段对其进行了表征;以BPA为目标污染物,考察了pH、BPA初始浓度、催化剂投加量及光照强度等因素对BPA去除效果的影响;同时,对该三元复合催化剂光催化降解BPA的机制进行了探讨...     

Ion-imprinted polymers for environmental monitoring of inorganic pollutants: synthesis, characterization, and applications

Ion imprinting has become one of the fast-growing technologies that have gained a lot of attention recently especially in the area of materials science. One of them is called the ion-imprinted polymers (IIPs). The IIPs are synthesized on the principles of enzyme phenomenon whereby a polymer is altered by a polymerization that takes place in the presence of a template that will be later removed to create cavities that will recognize only the analyte of interest. This specific and selective affinity for the target species decreases the chances of competition with other different types of ions. The imprinting technique started with the discovery of the bulk polymerization method where by the monomer, initiator, crosslinker, and template are mixed together and allowed to polymerize, and then the resulting polymer is ground and sieved to get particles with sizes suitable for the polymer's application. The IIPs have got some attractive qualities for use in environmental applications which include their stability and inexpensiveness and have a wide range of synthesis options with each suiting a certain unique application. Apart from environmental work, IIPs have applications in many other areas such as in membranes, in drug delivery, and in biosensors as alternatives to antibodies just to mention a few. This review focuses on the synthesis, types of imprinting, characterization, and applications of IIPs.     

Eco-friendly synthesis of nanostructured mesoporous materials from natural source rice husk silica for environmental applications

Environmental Science and Pollution Research - Nanostructured mesoporous materials of MCM-41 type were synthesized using a natural, non-toxic, and cheap source of silica from rice husk. Then, this...     

微波辅助法合成纳米ReFeO3光催化剂

以稀土金属硝酸盐La（NO3）3、Sm（NO3）3、Eu（NO3）3、Gd（NO3）3和Fe（NO3）3.9H2O为原材料,以活性炭为模板剂,聚乙烯醇（PVA）和尿素分别用作阻聚剂和均相沉淀剂,在微波辐照下制得纳米钙钛矿型化合物ReFeO3（Re：La,Sm,Eu,Gd）。用X射线粉末衍射仪（XRD）、UV-vis漫反射仪（DRS）、扫描电子显微镜（SEM）、透射电子显微镜（TEM）对产物组成、结构、颗粒大小、形貌等进行了表征,结果表明产物均为单一钙钛矿结构的纳米颗粒。以产物为光催化剂,在可见光照射下对罗丹明B水溶液进行光催化降解实验,发现该类化合物均具有较好的光催化活性,180 min内对罗丹明B的脱色率均达到85%以上。     

掺硼氧化银光催化剂制备及降解模拟印染废水

采用离子交换共沉淀法制备掺硼氧化银光催化剂并进行相应表征,以甲基橙为降解对象对其光催化氧化性能进行考察,并将其用于可见光下降解多种有机物及模拟印染废水。实验结果表明:掺硼氧化银光催化剂能带带隙为1.29 eV,具有很好的光催化氧化-还原能力,可见光下降解甲基橙,光照120 s可实现甲基橙完全降解;重复使用活性保持稳定;对不同有机物均可实现光催化氧化完全降解;模拟印染废水降解实验证实,在pH值5~10范围内,可见光照射下氧化银光催化剂在25 min内可实现混合染料的完全降解。掺硼氧化银是一种具有应用前景的可见光光催化剂。     

环境治理中光催化剂的失活与再生

催化剂失活是影响光催化过程用于污染治理经济实用的关键因素。对近几年来国内外环境污染控制中光催化剂的失活现象及其原因进行了综述．分析了液相和气相光催化反应体系中催化剂失活后再生的方法．特别是对气相光催化反应中水蒸汽的影响进行了讨论。     

Graphitic carbon nitride: a sustainable photocatalyst for organic pollutant degradation and antibacterial applications

Environmental Science and Pollution Research - Recently, graphitic carbon nitride (GCN) has been found to be of great interest in various sustainable applications. In this study, a simple...     

Nanoscale zero-valent metals: a review of synthesis,characterization, and applications to environmental remediation

Engineered nanoscale zero-valent metals (NZVMs) representing the forefront of technologies have been considered as promising materials for environmental remediation and antimicrobial effect, due to their high reducibility and strong adsorption capability. This review is focused on the methodology for synthesis of bare NZVMs, supported NZVMs, modified NZVMs, and bimetallic systems with both traditional and green methods. Recent studies have demonstrated that self-assembly methods can play an important role for obtaining ordered, controllable, and tunable NZVMs. In addition to common characterization methods, the state-of-the-art methods have been developed to obtain the properties of NZVMs (e.g., granularity, size distribution, specific surface area, shape, crystal form, and chemical bond) with the resolution down to subnanometer scale. These methods include spherical aberration corrected scanning transmission electron microscopy (Cs-corrected STEM), electron energy-loss spectroscopy (EELS), and near edge X-ray absorption fine structure (NEXAFS). A growing body of experimental data has proven that nanoscale zero-valent iron (NZVI) is highly effective and versatile. This article discusses the applications of NZVMs to treatment of heavy metals, halogenated organic compounds, polycyclic aromatic hydrocarbons, nutrients, radioelements, and microorganisms, using both ex situ and in situ methods. Furthermore, this paper briefly describes the ecotoxicological effects for NZVMs and the research prospects related to their synthesis, modification, characterization, and applications.     

A rapid and high-throughput quantum dots bioassay for monitoring of perfluorooctane sulfonate in environmental water samples

Currently HPLC/MS is the state of the art tool for environmental/drinking water perfluorooctane sulfonate (PFOS) monitoring. PFOS can bind to peroxisomal proliferator-activated receptor-alpha (PPARα), which forms heterodimers with retinoid X receptors (RXRs) and binds to PPAR response elements. In this bioassay free PFOS in water samples competes with immobilized PFOS in ELISA plates for a given amount of PPARα-RXRα. It can be determined indirectly by immobilizing PPARα-RXRα-PFOS complex to another plate coated with PPARα antibody and subsequent measuring the level of PPARα-RXRα by using biotin-modified PPARα-RXRα probes-quantum dots-streptavidin detection system. The rapid and high-throughput bioassay demonstrated a detection limit of 2.5 ng L⁻¹ with linear range between 2.5 ng L⁻¹ and 75 ng L⁻¹. Detection results of environmental water samples were highly consistent between the bioassay and HPLC/MS.     

A comprehensive review of hydrophobic silica and composite aerogels: synthesis,properties and recent progress towards environmental remediation and biomedical applications

Environmental Science and Pollution Research - The hydrophobicity of silica and composite aerogels has enabled them to acquire applications in a variety of fields. With remarkable structural,...     

Development of thermal programmed desorption mass spectrometry methods for environmental applications

The physical availability of hydrophobic organic contaminants (HOCs) bound to soils and sediments often controls their environmental toxicity. Currently, complicated and time extensive procedures are necessary to determine physical availability. The development of thermal programmed desorption mass spectrometry (TPD-MS) techniques for environmental samples may make it possible to evaluate the physical availability of HOCs in soils and sediments and also calculate relevant release energy values for bound contaminants. This work focused on developing the analytical protocols and data processing requirements for studying the desorption of HOCs from various simple geosorbents using TPD-MS. The work seeks to document the use of the TPD-MS method as an environmental assessment tool and provide the reader with a working knowledge of the entire process.     

Modification of cyclodextrin and use in environmental applications

Environmental Science and Pollution Research - Water pollution, which has become a global problem in parallel with environmental pollution, is a problem that needs to be solved urgently,...     

A fast one-pot synthesize of crystalline anglesite by hydrothermal synthesis for environmental assessment on pure phase

Environmental Science and Pollution Research - Anglesite (PbSO4) is a lead sulfate that belongs to the barite group and is naturally ubiquitous in the environment. This work describes a simple way...     

Ag／ZnO光催化降解甲基对硫磷研究

描述了掺杂体系Ａｇ／ＺｎＯ用于甲基对硫磷水溶液光催化降解,有氧存在下,经ＵＶ照射对甲基对硫磷光降解是有效的,并讨论了影响光降解中甲基硫磷诸因素,初步探讨了光降解机理和动力学,起始降解物为Ｃ２Ｈ６Ｐ＾＋Ｓ和Ｏ２ＮＨ４Ｏ,且是一级反应,半衰期为１．８２ｍｉｎ。     

TiO2晶体的微波水热法制备及光催化性能研究

以TiSO4和尿素为主要原料,EDTA为控制剂,采用微波水热法制备纳米TiO2光催化剂,并分析了纳米TiO2晶粒的最佳形成条件。利用XRD、TEM等技术对制备产物进行表征。结果表明,TiSO4和尿素混合物在微波水热条件下晶化150min后,产物为锐钛矿型TiO2,且产物粒径小、大小均匀。在紫外光照射下,以自制的锐钛矿型纳米TiO2为催化剂,酸性橙为降解目标物,进一步研究了其光催化性能。结果表明,该TiO2在紫外光照射下表现出稳定的光催化活性。     

宏基因组学在环境工程领域的应用及研究进展

宏基因组学作为环境生物学(特别是环境微生物学)和基因组学结合而产生的新兴学科,利用其独特的生物分子检测技术和高通量基因筛选方法,在环境微生物群落研究和资源开发上取得了一系列突破性的进展,并逐步应用到环境科学与工程的各个领域。旨在通过对宏基因组技术的简单介绍,总结近期它在环境工程领域,如水处理工程、污染土壤生物修复、生活垃圾生物处理、海洋及其他生境石油泄漏修复和生物电化学工程中的应用和进展。同时,也为环境工程领域中生物处理技术的改进提供更多微生物层面上的理论依据和方法学思路,并对宏基因组学在环境工程领域内的应用和发展进行了展望。     

TiO_2晶体的微波水热法制备及光催化性能研究

以TiSO4和尿素为主要原料,EDTA为控制剂,采用微波水热法制备纳米TiO2光催化剂,并分析了纳米TiO2晶粒的最佳形成条件。利用XRD、TEM等技术对制备产物进行表征。结果表明,TiSO4和尿素混合物在微波水热条件下晶化150 min后,产物为锐钛矿型TiO2,且产物粒径小、大小均匀。在紫外光照射下,以自制的锐钛矿型纳米TiO2为催化剂,酸性橙为降解目标物,进一步研究了其光催化性能。结果表明,该TiO2在紫外光照射下表现出稳定的光催化活性。     

Fe/Si/TiO2三元复合光催化剂的性能研究

用溶胶-凝胶法制备了Fe/Si/TiO2三元复合光催化剂,利用X射线衍射(XRD)和紫外-可见漫反射光谱(DRS)对样品进行了分析表征,并以甲基橙为模拟污染物,考察了其光催化活性.结果表明,Fe/Si/TiO2三元复合光催化剂与TiO2相比,光催化活性明显提高;当煅烧温度为900℃、添加Fe的摩尔分数为0.050%时,光催化活性最佳.     

磁性Fe_3O_4/Ag_3PO_4复合光催化剂催化降解染料废水中的孔雀石绿

利用离子交换法制备了可磁性分离并具有高效可见光催化活性的Fe3O4/Ag3PO4复合光催化剂,对制备的样品进行了粉末X射线衍射(XRD)表征。同时,用孔雀石绿溶液模拟染料废水,考察了孔雀石绿溶液的初始浓度、催化剂投加量及溶液初始pH值对复合光催化剂催化降解孔雀石绿效果的影响,并探讨了Fe3O4/Ag3PO4磁性复合光催化剂的回收及循环利用特性。结果表明,该复合光催化剂在可见光照射下表现出较高的催化活性;当孔雀石绿溶液浓度为5mg/L、复合催化剂投加量为200mg/L、溶液初始pH=3.0、可见光照20min时,Fe3O4/Ag3PO4复合光催化剂对孔雀石绿的去除率可达96%;反应结束后,磁性复合光催化剂在外加磁场作用下,易于从反应体系中分离,循环使用3次后,其光催化效率仍可达到60%。实验表明,制备的复合光催化剂对染料废水中孔雀石绿有较高的降解效率,并具有优良的回收利用性。