Iron-based biochar as efficient persulfate activation catalyst for emerging pollutants removal: A review

In recent years, biochar (BC) as a low-cost, easily available biomass product, is widely applied in sulfate radical-based advanced oxidation processes (SR-AOPs) for emerging pollutants remediation. Herein, a state-of-art review of iron-based biochar catalysts is currently available in SR-AOPs application. A general summary of the development of biochar and the catalytic properties of biochar is presented. Especially, the synthetic strategies of different types of iron-based biochar catalysts are discussed. Moreover, the theoretical calculation to interpret the interaction between biochar and iron species is discussed to explore the activation mechanisms. And the regeneration methods of biochar-based catalyst are presented. The unresolved challenges of the existent biochar-based SR-AOPs are pointed out, and the outlooks of future research directions are proposed.     

Analytical procedures for the determination of emerging organic contaminants in plant material: A review

In this review, recent developments for the determination of emerging organic contaminants (EOCs) in plant tissues are discussed focusing on the homogenization, extraction and determination steps involved. Eleven classes of EOCs, namely antibiotics, analgesics, antiepileptics, antidepressants, antiseptics, plasticizers, fragrances, surfactants, flame retardants, and phenoxy acid herbicides, have been evaluated. Methods are critically reviewed in terms of all the analytical steps involved in the analysis, sampling and sample preparation, separation, and the detection strategies employed. The extraction from tissue samples was performed in most cases by solid–liquid extraction, whereas the clean-up was performed by solid-phase extraction. The identification and quantification of EOCs in crops from the agricultural field (i.e. parts per billion range) is usually performed by using mass spectrometry techniques such as single quadrupole mass spectrometry or tandem mass spectrometry coupled to high resolution chromatographic techniques. Enzyme-linked immunosorbent assays are more rarely used. New developments such as in vivo solid-phase microextraction (SPME) and the assessment of the bioavailability–bioaccesibility of contaminants in crops are shown. The main scope of this review is to critically evaluate the current state of the art of the analytical techniques used and to identify the research needs in the determination of EOCs in crops.     

A series of highly efficient photocatalysts for organic contaminants degradation under visible light irradiation

Antimonic acid and N-doped antimonic acid, solid acids with d(10) electron configuration, are reported as novel photocatalysts for rhodamine B (RhB) degradation under visible light irradiation. They show much higher activities in comparison with P25 and photolysis. However, the extent of degradation abilities for RhB was not consistent with the formation rate of the active ˙OH radicals under visible light irradiation.     

Analysis of emerging organic contaminants in environmental solid samples

Spreading sewage sludge on agricultural lands has been actively promoted by national authorities as an economic way of recycling. However, as by-product of wastewater treatment, sewage sludge may contain toxic substances, which could be incorporated into agricultural products or be distributed in the environment. Moreover, sediments can be contaminated by the discharge of wastewater effluents into rivers. This article reviews the determination of emerging contaminants (surfactants, flame retardants, pharmaceuticals and personal care products) in environmental solid samples (sludge, soil and sediment). Sample preparation, including extraction and clean-up, as well as the subsequent instrumental determination of contaminants are discussed. Recent applications of extraction techniques, such as Soxhlet extraction, ultrasound assisted extraction, pressurised liquid extraction, microwave assisted extraction and matrix solid-phase dispersion to the analysis of emerging contaminants in environmental solid samples are reviewed. Determination of these contaminants, generally carried out by gas chromatography and liquid chromatography coupled with different detectors, especially mass spectrometry for the identification and quantification of residues, is also summarised and discussed.      

Organohalogen contaminants of emerging concern in Great Lakes fish: a review

Organohalogen chemicals of emerging concern (CECs) have attracted much attention during the past decade and are of special importance for the Great Lakes of North America, which are together the largest surface freshwater resource on the earth. In this paper we review and summarize detection and levels of legacy contaminants in Great Lakes fish, lessons learned from legacy contaminants in advancing the analytical detection of CECs, progress and challenges in measuring CECs, and levels of CECs in Great Lakes fish reported to date. The CECs considered include chlorinated paraffins, polychlorinated naphthalenes and other chlorinated aromatics, halogenated flame retardants, and perfluorinated compounds.     

In-situ synthesis of N,S co-doped hollow carbon microspheres for efficient catalytic oxidation of organic contaminants

Metal-free heteroatom doped nanocarbons are promising alternatives to the metal-based materials in catalytic ozonation for destruction of aqueous organic contaminants.In this study,N,S co-doped hollow carbon microspheres（NSCs） were synthesized from the polymerization products during persulfate wet air oxidation of benzothiazole.The contents of doped N and S as well as the structural stability were maneuvered by adjusting the subsequent N₂-annealing temperature.Compared with the prevai...     

A new optical fiber reactor for the photocatalytic degradation of gaseous organic contaminants

The main objective of this study was to develop a simple, energy-efficient photoreactor for operating at room temperature. In this work, the design of a new gas-phase optical fiber photoreactor (OFP) was introduced which operated under various parameters, such as the UV light intensity and the initial concentration for the photocatalytic decomposition of acetone. Experimental results indicated that increasing the UV light intensity or decreasing the initial concentrations of acetone by a UV/TiO₂ process would result in improving the decomposition and mineralization efficiencies. The apparent quantum yield of the novel optical fiber reactor is about 2 to 3 times greater than that of the traditional annular reactor.     

Highly efficient degradation of emerging contaminants by magnetic CuO@FexOy derived from natural mackinawite（FeS） in the presence of peroxymonosulfate

In this study,natural mackinawite （Fe S）,a chalcophilic mineral,was utilized to prepare iron/copper bimetallic oxides （Cu O@Fe_xO_y） by displacement plating and calcination process.Various characterization methods prove that Cu⁰is successfully coated on the surface of Fe S,which were further oxidized to Cu O,Fe₃O₄and/or Fe₂O₃during calcination process,respectively.Cu O@Fe_xO_yperformed highly efficient...     

Ecotoxicological effects of combined UVB and organic contaminants in coastal waters: A review

Organisms living in coastal waters are exposed to anthropogenic contaminants from terrestrial drainage, ice melting and maritime traffic and to enhanced UVB radiation (UVBR; 280-320 nm) caused by decreased concentrations of ozone in the stratosphere. This article reviews available information about the combined effects of UVBR and selected hydrosoluble contaminants potentially present in surface waters on marine species and especially on plankton community structure in high-latitude coastal zones. Effects of UVBR on three selected pesticides (Atrazine, carbaryl and Acifluorfen) and possible induction of phototoxicity are reviewed. Most toxicological studies have been conducted under laboratory conditions with questionable relevance for coastal marine ecosystems. Similarly, photoactivation of polycyclic aromatic hydrocarbons (PAHs) has been closely examined and reported effects on aquatic species summarized. Experiments with field-sampled communities demonstrated the complexity and the difficulty in determining the impact of multiple stressors on an aquatic ecosystem, even for ecosystems simplified by eliminating large grazers and fish. Nutrient status, specific composition and light history have influenced the different responses of planktonic assemblages exposed to enhanced UVBR and water-soluble fraction (WSF) from crude oil or to tributyltin. Plankton assemblages subjected to changes in the ozone hole were physiologically stressed and more susceptible to WSF toxicity than communities from less enhanced UVBR-impacted sites. A close relationship between phytoplankton assemblages and bacteria was observed in all experiments in mesocosms. A contaminant-induced phytoplankton crash after a bloom event may release important carbon and nutrient sources for bacteria. The magnitude of phytoplanktonic mortality induced by a contaminant probably influenced how rapidly bacteria grew over time. The transition from a herbivorous food web to a microbial food web has significant ecological implications for carbon cycling and energy flow in pelagic systems. A high phytoplankton mortality implies a situation in which the potential for downward carbon export from surface waters is high. In contrast, high bacterial enrichment implies that the phytoplankton carbon is largely recycled in surface waters through a microbial loop and does not contribute significantly to sinking particle flux. The most ecologically relevant results were obtained with mesocosm studies using field-collected communities. The enhancement of hydrocarbon toxicity in the presence of a high level of UVBR cannot be described as being a synergistic or an additive effect, because the WSF alone is not toxic and may even be beneficial by increasing bacterial activity. This is a case in which one stressor has the ability to modify another stressor to cause it to be toxic to target organisms. These abiotically induced interactions may be important for biological communities exposed to extreme conditions when physical, chemical or photochemical reactions modify the nature of environmental stressors before they interact with biological functions. The need for models on the impacts of multiple stressors on biodiversity and ecosystem functioning is emphasized.     

An inescapable fact: Toxicity increase during photo-driven degradation of emerging contaminants in water environments

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Analytical methods for the determination of emerging organic contaminants in the atmosphere

Concerns over the occurrence and transport of emerging organic contaminants (EOCs) from local sources to remote regions have resulted in wide developments in sampling strategy and analytical methodology for the determination of trace concentrations of EOCs in the atmosphere. This article discusses developments in the determination of EOCs in ambient air which includes polyfluorinated alkyl substances (PFASs), brominated-flame retardants (BFRs), synthesis musk fragrances, and alkylphenols (APs). References were mainly summarized from the past 5 years (2002 up to present) on new developments of sampling methods, extraction, separation/fractionation and/or applications of new technologies for sampling and determination.     

Catalytic degradation of lomefloxacin by photo-assisted persulfate activation on natural hematite: Performance and mechanism

The photo-assisted hematite nanoparticles activated persulfate system was constructed and used to remove nonbiodegradable organic pollutants in water. A possible reaction mechanism of as-obtained system was proposed based on the analysis characterization and experimental results.

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Synthesis of Zr-based MOF nanocomposites for efficient visible-light photocatalytic degradation of contaminants

Research on Chemical Intermediates - A novel ternary complex photocatalyst (UiO-66/g-C3N4/Ag) was fabricated by chemical protonation coating and photodeposition and its physicochemical parameters,...     

Photocatalytic degradation of organic pollutants by MOFs based materials: A review

Metal-organic frameworks (MOFs) are currently popular porous materials with research and application value in various fields. Aiming at the application of MOFs in photocatalysis, this paper mainly reviews the main synthesis methods of MOFs and the latest research progress of MOFs-based photocatalysts to degrade organic pollutants in water, such as organic dyes, pharmaceuticals and personal care products, and other organic pollutants. The main characteristics of different synthesis methods of MOFs, the main design strategies of MOFs-based photocatalysts, and the excellent performance of photocatalytic degradation of organic pollutants are summarized. At the end of this paper, the practical application of MOFs, the current limitations of MOFs, the synthesis methods of MOFs, and the future development trend of MOFs photocatalysts are explained.     

冷冻干燥技术在环境水样有机新污染物前处理中的应用进展

有机新污染物是一类在先进分析技术帮助下新鉴定的、现有法规未管制的、人为源的有机污染物.有机新污染物主要包括药品与个人护理、农药、全氟化合物、内分泌干扰物等,其会产生内分泌干扰效应、诱发抗性基因传播,还对人类和野生生物的生存与发展构成潜在威胁,因此检测环境样品中的有机新污染物浓度对生态环境和人体健康具有重大意义.由于环境...