Ammonia (NH) is a highly important industrial chemical used as fuel and fertilizer. The industrial synthesis of NH relies heavily on the Haber-Bosch route, which accounts for roughly 1.2% of global annual CO emissions.
View Article and Find Full Text PDFThe activation of peracetic acid (PAA) by using Fe has been used to degrade emerging micropollutants in water, the slow cycle of Fe/Fe however limits the process efficiency, and debates on the dominant reactive species are still ongoing. This study investigated Fe-catalyzed PAA under ultraviolet-A (UVA) irradiation toward the degradation of five representative micropollutants (carbamazepine, diclofenac, naproxen, sulfamethoxazole and trimethoprim). The results showed that PAA was efficiently catalyzed by trace Fe (≤ 10 μM) with the synergy of UVA, resulting in more efficient naproxen degradation than that by inorganic peroxides (HO/persulfates)-based photo-Fenton processes.
View Article and Find Full Text PDFThis study investigated the advanced treatment of secondary effluent organic matters (EfOM) from an industrial park wastewater treatment plant (IPWTP) by Fenton oxidation process and its combination with biological aerated filter (BAF). The constituents of EfOM were characterized by using fluorescence excitation-emission matrix, and the results showed that the major components included aromatic proteins, soluble microbial products, humic and fulvic acid-like substances, and compounds associated with fluorescent region of Ex 250-300 nm/Em 600-700 nm. The EfOM was strongly resistant to biodegradation (biochemical oxygen demand (BOD):chemical oxygen demand (COD) ratio at 0.
View Article and Find Full Text PDFSupported copper oxides with well-dispersed metal species, small size, tunable valence and high stability are highly desirable in catalysis. Herein, novel copper oxide (CuO) catalysts supported on defect-rich mesoporous alumina microspheres are developed using a spray-drying-assisted evaporation induced self-assembly method. The catalysts possess a special structure composed of a mesoporous outer layer, a mesoporous-nanosphere-stacked under layer and a hollow cavity.
View Article and Find Full Text PDFBimetallic Fe-Mn oxide (BFMO) has been regarded as a promising activator of peroxysulfate (PS), the sustained activity and durability of BFMO for long-term activation of PS in situ, however, is unclear for groundwater remediation. A BFMO (i.e.
View Article and Find Full Text PDFFerric-nitrilotriacetate complex (Fe-NTA) has been adopted to catalyze the photo-Fenton degradation of emerging pharmaceutical micropollutants in water and wastewater at neutral pH. The generation of hydroxyl radicals (HO) in UVA/Fe-NTA/HO was identified by using electron spin resonance (ESR) trapping technique. The effects of critical parameters (e.
View Article and Find Full Text PDFIn this paper, we demonstrate the facile and general synthesis of alkaline-earth metal manganites, denoted as A(Mg, Ca, Ba)MnO, for efficient degradation of high-concentration phenolic compounds via catalytic ozonation. The representative CaMnO oxides show a hierarchical spherical structure constructed by crystalline nanorods and numerous macropores. They possess mixed Mn/Mn chemical valences and abundant surface hydroxyl (OH) groups.
View Article and Find Full Text PDFCompetitive adsorption of As(V) and Sb(V) at environmentally relevant concentrations onto ferrihydrite was investigated. Batch experiments and XPS analyses confirmed that in a binary system, the presence of Sb(V) exhibited a slight synergistic effect on As(V) adsorption. XPS analyses showed that As(V) and Sb(V) adsorption led to obvious diminishment of Fe-O-Fe and Fe-O-H bonds respectively.
View Article and Find Full Text PDFTrichloroethylene (TCE) degradation in sand columns has been investigated to evaluate the potential of chelates-enhanced Fenton-like reaction with magnetite as iron source for in situ treatment of TCE-contaminated groundwater. The results showed that successful degradation of TCE in sand columns was obtained by nitrilotriacetic acid (NTA)-assisted Fenton-like reaction of magnetite. Addition of ethylenediaminedisuccinic acid (EDDS) resulted in an inhibitory effect on TCE degradation in sand columns.
View Article and Find Full Text PDFEnviron Sci Pollut Res Int
July 2017
The present study investigated the degradation of trichloroethylene (TCE) in sand suspensions by Fenton-like reaction with magnetite (FeO) in the presence of various chelators at circumneutral pH. The results showed that ethylenediaminetetraacetic acid (EDTA) and nitrilotriacetic acid (NTA) greatly improved the rate of TCE degradation, while [S,S]-ethylenediaminedisuccinic acid (s,s-EDDS), malonate, citrate, and phytic acid (IP6) have minimal effects on TCE degradation. Quenching tests suggested that TCE was mainly degraded by hydroxyl radical (HO) attack, with about 90% inhibition on TCE degradation by the addition of HO scavenger 2-propanol.
View Article and Find Full Text PDFIn this work, we report a novel Mn(2+)-mediated Fenton-like process based on Fe(III)-NTA complex that is super-efficient at circumneutral pH range. Kinetics experiments showed that the presence of Mn(2+) significantly enhanced the effectiveness of Fe(III)-NTA complex catalyzed Fenton-like reaction. The degradation rate constant of crotamiton (CRMT), a model compound, by the Fe(III)- NTA_Mn(2+) Fenton-like process was at least 1.
View Article and Find Full Text PDFIEEE Trans Image Process
December 2014
In the 3D facial animation and synthesis community, input faces are usually required to be labeled by a set of landmarks for parameterization. Because of the variations in pose, expression and resolution, automatic 3D face landmark localization remains a challenge. In this paper, a novel landmark localization approach is presented.
View Article and Find Full Text PDF3-D facial expression generation, including synthesis and retargeting, has received intensive attentions in recent years, because it is important to produce realistic 3-D faces with specific expressions in modern film production and computer games. In this paper, we present joint sparse learning (JSL) to learn mapping functions and their respective inverses to model the relationship between the high-dimensional 3-D faces (of different expressions and identities) and their corresponding low-dimensional representations. Based on JSL, we can effectively and efficiently generate various expressions of a 3-D face by either synthesizing or retargeting.
View Article and Find Full Text PDFThis study investigated the kinetics and mechanism of carbamazepine (CBZ) degradation over an initial pH range of 5.0-9.0 by a modified Fenton-like reaction using ferric-nitrilotriacetate (Fe(III)-NTA) complexes.
View Article and Find Full Text PDFEnviron Sci Pollut Res Int
January 2013
The objective of this study is to investigate and understand the oxidizing properties of a manganese oxide, specifically synthetic cryptomelane (KMn(8)O(16)) and its derivatives, in aqueous solution. Ciprofloxacin (CIP), a commonly used fluoroquinolone antibiotic, was used as the probe. Synthetic cryptomelane, known as octahedral molecular sieves (OMS-2), was synthesized, and its derivatives were prepared by adding transition metal oxides, V(2)O(5) or MoO(3), as dopants during synthesis.
View Article and Find Full Text PDFOne-stage autotrophic nitrogen (N) removal, requiring the simultaneous activity of aerobic and anaerobic ammonium oxidizing bacteria (AOB and AnAOB), can be obtained in spatially redox-stratified biofilms. However, previous experience with Membrane-Aerated Biofilm Reactors (MABRs) has revealed a difficulty in reducing the abundance and activity of nitrite oxidizing bacteria (NOB), which drastically lowers process efficiency. Here we show how sequential aeration is an effective strategy to attain autotrophic N removal in MABRs: Two separate MABRs, which displayed limited or no N removal under continuous aeration, could remove more than 5.
View Article and Find Full Text PDFA novel dumbbell-shaped ZnO photocatalyst was successfully synthesized by microwave heating in the present study. The prepared ZnO photocatalysts were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and UV-Vis absorption spectrum (UV-Vis). The results indicated that the prepared ZnO photocatalyst shows a united dumbbell shape with 2 microm diameter and 5 microm length.
View Article and Find Full Text PDFA novel dumbbell-shaped ZnO microcrystal photocatalyst was successfully synthesized by hydrothermal method in the present study. The prepared ZnO photocatalyst was systematically characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric analysis (TG-DTA), photoluminescence spectrum (PL) and UV-vis absorption spectrum (UV-vis). The characterizations of dumbbell-shaped ZnO were also compared with the commercial ZnO.
View Article and Find Full Text PDFTo establish cost-efficient operating conditions for potential application of Fenton oxidation process to treat wastewater containing an azo dye Orange G (OG), some important operating parameters such as pH value of solutions, dosages of H(2)O(2) and Fe(2+), temperature, presence/absence of chloride ion and concentration of the dye, which effect on the decolorization of OG in aqueous solution by Fenton oxidation have been investigated systematically. In addition, the decolorization kinetics of OG was also elucidated based on the experimental data. The results showed that a suitable decolorization condition was selected as initial pH 4.
View Article and Find Full Text PDFIn this paper, the degradation of an azo dye Orange G (OG) on nitrogen-doped TiO2 photocatalysts has been investigated under visible light and sunlight irradiation. Under visible light irradiation, the doped TiO2 nanocatalysts demonstrated higher activity than the commercial Dugussa P25 TiO2, allowing more efficient utilization of solar light, while under sunlight, P25 showed higher photocatalytic activity. According to the X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and UV-vis spectra analyses, it was found that both the nanosized anatase structure and the appearance of new absorption band in the visible region caused by nitrogen doping were responsible for the significant enhancement of OG degradation under visible light.
View Article and Find Full Text PDFThe degradation of p-nitroaniline (PNA) in water by solar photo-Fenton advanced oxidation process was investigated in this study. The effects of different reaction parameters including pH value of solutions, dosages of hydrogen peroxide and ferrous ion, initial PNA concentration and temperature on the degradation of PNA have been studied. The optimum conditions for the degradation of PNA in water were considered to be: the pH value at 3.
View Article and Find Full Text PDFA detailed kinetic model was developed for the degradation of p-nitroaniline (PNA) by Fenton oxidation. Batch experiments were carried out to investigate the role of pH, hydrogen peroxide and Fe(2+) levels, PNA concentration and the temperature. The kinetic rate constants, k(ap), for PNA degradation at different reaction conditions were determined.
View Article and Find Full Text PDFA combination of ultrasonic and low concentration iron (<3 mgL(-1)) of Fenton process (US/Fenton) has been used to treat wastewater containing Acid black 1 (AB1). The results show that the oxidation power of low concentration iron of Fenton could be significantly enhanced by ultrasonic irradiation. The degradation of AB1 in aqueous solution by US/Fenton can receive better results compared with either Fenton oxidation or ultrasonic alone.
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