Effects of tri-o-cresyl phosphate on serum estrogen and progesterone concentration and ATPase activity in the shell gland of adult hens

Synthesis of nitrogen and terbium co-doped TiO2 nanocrystals with enhanced photocatalytic activity for AO7 degradation under visible-light radiation

TiO2 nanocrystals co-doped with nitrogen and terbium exhibited extended light absorption, improved charge separation efficiency, and enhanced AO7 adsorption efficiency, giving rise to enhanced AO7 degradation activity which was 2× better than undoped TiO2 nanocrystals.

Tri-ortho-cresyl phosphate exposure leads to low egg production and poor eggshell quality via disrupting follicular development and shell gland function in laying hens

Tri-ortho-cresyl phosphate (TOCP) has been used commercially as a plasticizer and a flame retardant, which has been reported to cause multiple toxicities in humans and other animals. However, the effect of TOCP on female reproductive system is still unclear. The aim of this investigation was to evaluate the reproductive toxicity of TOCP in female avian and investigate its molecular mechanism. In the current study, 50 adult hens were given a single oral dose of TOCP (750 mg/kg). Egg laid by the hens were harvested and counted. Egg quality is assessed by determining the shell strength and thickness. Samples of ovary, shell gland, and serum were collected on day 0, 2, 7, and 21 after the administration. The morphological and pathological changes in tissues were examined. Cell death, follicular development, and steroidogenesis were determined to assess the toxicity of TOCP on laying hens. The results showed that egg production, egg weight, and eggshell strength significantly decreased after TOCP exposure. The calcium levels in serum and eggshell decreased and the expression levels of the eggshell formation-related genes calbindin-D28k (CaBP-D28k) and carbonic anhydrase 2 (CA2) were downregulated. The inhibitory effects of TOCP on follicular development and steroidogenesis were observed with changes in the levels of the related proteins such as forkhead box O1 (FoxO1) and mothers against decapentaplegic homolog 2/3 (Smad2/3). Cell death was identified, which might lead to follicular development disorder. Taken together, TOCP reduced the quantity and quality of the eggs laid by the hens through disrupting follicular development, steroidogenesis, and shell gland function.

Methyl bromide production from dissolved organic matter under simulated sunlight irradiation and the important effect of ferric ions

The oceans play an important role in the biogeochemical cycle of methyl bromide (CH₃Br), as not only the sinks but also the sources. However, many uncertainties exist regarding the way of CH₃Br generation in the marine environment. To illustrate the possibility of photochemical formation of CH₃Br in saline water, its generation in bromide aqueous solution containing humic acid (HA) and ferric ions (Fe(iii)) was investigated. CH₃Br was obviously generated after irradiation, and its amounts increased with increasing HA concentration from 0.82 to 12.2 mgC L^-1. Fe(iii) significantly promoted CH₃Br production, and the described production process in the presence of Fe(iii) was pH-dependent, decreasing with the increase of pH. Finally, the concentrations of CH₃Br in natural coastal seawater and seawater with HA were measured, and the results showed that CH₃Br was significantly generated under irradiation. Our results suggest that the photochemical process of dissolved organic matter may be one source of CH₃Br in the marine environment.

Removal of Acid Blue 62 textile dye from aqueous solutions by cerium reagents

The removal of Acid Blue 62 (AB62) dye which is known as a pollutant agent and contains in wastewater of textile industry has been studied in this work by using five various cerium compounds as the oxidizing agents. The parameters involved in the oxidation reaction such as pH, initial dye concentration and the oxidizing agent dosage have been investigated using both batch and semi-batch reactors at ambient temperature. The results indicated that the rate of oxidation for various cerium reagents is in the following order: CeF₄ > (NH₄)₂Ce (NO₃)₆> Ce (SO₄)₂ > CeCl₃ > Ce (CH₃COO)₃, where cerium fluoride (CeF₄) had the highest removal yields, 99.9% and 95%, for dye de-colouration and COD (chemical oxygen demand), respectively. The analysis of the dye removal was done by using UV-VIS spectrometry, GC-MS and HPLC methods which indicated the aromatic ring cleavage of AB62 dye by CeF₄. The half-life measurement was employed to evaluate the reaction rate model for decomposition of AB62 dye by CeF₄.

Tri-ortho-cresyl phosphate (TOCP)-induced reproductive toxicity involved in placental apoptosis, autophagy and oxidative stress in pregnant mice

Tri-ortho-cresyl phosphate (TOCP) has been widely used as plasticizers, and reported causing reproductive toxicity in mammals. However, little is known about the toxic effect on the placenta. In this study, dams were orally administered different doses of TOCP to explore the effect of TOCP on placental development. Results showed that TOCP exposure significantly reduced numbers of implanted embryo, caused atrophy and collapse of ectoplacental cone, and decreased total areas of placenta and numbers of PCNA-positive cells. Expression levels of placental development genes were prominently downregulated in the TOCP-treated groups. Moreover, TOCP administration induced placental apoptosis and autophagy by upregulating P53, Bax, Beclin-1, ratio of LC3 II/LC3 I and Atg5 and downregulating Bcl-2 protein. In addition, TOCP exposure markedly inhibited activities of catalase and superoxide dismutase and increased the production of H₂ O₂ and malondialdehyde. Collectively, these findings suggest that apoptosis, autophagy and oxidative stress may be involved in the TOCP-induced reproductive toxicity.

Tri-ortho-cresyl phosphate induces autophagy of mouse ovarian granulosa cells

Tri-ortho-cresyl phosphate (TOCP) has been widely used as plasticizers, plastic softeners and flame-retardants in industry and reported to have male reproductive toxicology. However, it is still unknown whether TOCP affects the female reproductive system and its underlying mechanism. In the present study, we found that TOCP exposure significantly decreased ovarian coefficient, caused disintegration and depletion of the granulosa cells in the ovary tissue and significantly inhibited the level of serum estradiol (E2). TOCP markedly increased both LC3-II and the ratio of LC3-II/LC3-I as well as autophagy proteins ATG5 and Beclin1 in the ovary tissue, implying that TOCP could induce autophagy in the ovary tissue. To further investigate the potential mechanism, primary ovarian granulosa cells were isolated in vitro and treated with 0–0.5 mM TOCP for 48 h. We showed that TOCP decreased the number of viable mouse granulosa cells without affecting cell cycle and apoptosis of the cells. Intriguingly, TOCP treatment markedly increased both LC3-II and the ratio of LC3-II/LC3-I as well as ATG5 and Beclin1. Furthermore, transmission electron microscopy (TEM) showed that autophagic vesicles in the cytoplasm increased significantly in the TOCP-treated cells, indicating that TOCP could induce autophagy in the cells. Taken together, TOCP reduces the number of viable cells and induces autophagy in mouse ovarian granulosa cells without affecting cell cycle and apoptosis.

Photogeneration of hydroxyl radical in Fe(III)-citrate-oxalate system for the degradation of fluconazole: mechanism and products

The photochemical role of Fe(III)-citrate complex is significant in natural waters due to its ubiquitous existence and excellent photoreactivity at near neutral pH. Although there are many reports on the photoinduced degradation of pollutants in the Fe(III)-citrate system, the optimum pH for its photoreactivity is yet not clearly understood. Here, for the first time, we demonstrated that the optimum pH was 5.5 for the photoproduction of ^•OH in the Fe(III)-citrate system via kinetics modeling based on the steady-state approximation. According to the experimental results, the ^•OH photoproduction increased with increasing pH until 5.5 and then decreased in Fe(III)-citrate solution, which agreed well with the prediction trend of kinetic modeling. The effect of the common ligand oxalate on the photoreactivity of Fe(III)-citrate system was also investigated. The addition of oxalate promoted the photoproduction of ^•OH in Fe(III)-citrate solutions, and the measured [^•OH]_ss increased with oxalate concentration under a fixed Fe(III)-to-citrate ratio. Little synergistic effect exists in Fe(III)-citrate-oxalate system at pH 4.0-5.5. In contrast, an appreciable synergistic effect was observed at near neutral pH (6.0-8.0). Higher oxalate-to-citrate ratio facilitated the synergistic effect. Furthermore, antifungal drug fluconazole could be removed efficiently in the Fe(III)-citrate-oxalate system. The photodegradation kinetics also verified the optimum pH of Fe(III)-citrate system and synergistic effect of oxalate. By LC-ESI-MS/MS analyses, the photoproducts of fluconazole in the Fe(III)-citrate-oxalate system were identified and the reaction mechanism involving hydroxylation substitution and subsequent cleavage of heterocyclic amine was proposed. These findings suggest that Fe(III)-citrate exhibits best photoreactivity at pH 5.5, and the coexistence of reactive ligands will enhance its photoreactivity at circumneutral pH, indicating potential application in wastewater treatment via addition of appropriate citrate and co-ligands.

Visual detection of H2O2 and melamine based on PW11MO39n− (M = Cu2+, Co2+, Mn2+, Fe3+) and PW9M3O34n− (M = Cu2+, Co2+, Mn2+, Fe3+)

The peroxidase-like activity of transition metal-substituted polyoxometalates (PW₁₁MO₃₉ⁿ⁻, PW₉M₃O₃₄ⁿ⁻, abbreviated as PW₁₁M and PW₉M₃, where M = Cu²⁺, Co²⁺, Mn²⁺, Fe³⁺) in the oxidation of 3,3′,5,5′-tetramethylbenzidine by H₂O₂ was valuated.

The degradation of azo dye with different cathode and anode structures in biofilm electrode reactors

In this study, biofilm electrode reactors (BERs) were constructed to degrade the azo dye Reactive Brilliant Red (RBR) X-3B.

Efficient mineralization of phenol by a temperature-responsive polyoxometalate catalyst under wet peroxide oxidation at lower temperatures

Herein, a temperature-responsive polyoxometalate (POM) catalyst [C₁₆H₃₃(CH₃)₃N]₃[PO₄{WO(O₂)₂}₄]/poly(N-isopropylacrylamide) (abbreviated as (C₁₆PW(O₂)₂/PNIPAM) was prepared and used in the catalytic wet peroxide oxidation (CWPO) of phenol under mild conditions.

Rapid degradation of azo-dye using Mn–Al powders produced by ball-milling

This study was conducted on the reduction reaction of the azo dye Reactive Black 5 by means of the Mn₈₅Al₁₅ particles prepared by melt-spinning and ball-milling processes.

Micro-Nanocomposites in Environmental Management

Water pollution, a worldwide issue for the human society, has raised global concerns on environmental sustainability, calling for high-performance materials for effective treatments. Since the traditional techniques have inherent limitations in treatment speed and efficiency, nanotechnology is subsequently used as an environmental technology to remove pollutants through a rapid adsorption and degradation process. Therefore, here, various adsorbent and photodegradation composite materials leading to effective water remediation are summarized and predicted. Notably, recent advances in simultaneous adsorption and photodegradation micro-nanocomposites are outlined. Such materials can not only completely adsorb and remove contaminants, but the micro-nanocomposites can also be directly reused without further treatment. Finally, the future development of this unique system is discussed.

Photochemical transformation of an iron(iii)–arsenite complex in acidic aqueous solution

An Fe(iii)–As(iii) complex was characterized by UV/Vis spectra and its laser flash photolysis via ligand-to-metal charge transfer resulted in the intermediate of Fe(ii)–As(iv).

Oxidative photodegradation of herbicide fenuron in aqueous solution by natural iron oxide α-Fe2O3, influence of polycarboxylic acids

The photodegradation of the herbicide fenuron (1,1-dimethyl-3-phenylurea) by using a natural iron oxide (NIO), α-Fe2O3, in aqueous solution at acidic pH has been undertaken. The NIO was characterized by the Raman spectroscopy method. The degradation pathways and the formation of degradation products were studied. A high-pressure mercury lamp and sunlight were employed as light source. Fenuron photodegradation using NIO with oxalic acid followed the pseudo-first-order kinetics, the optimal experimental conditions were [oxalic acid]0 = 10(-3) M and [NIO] = 0.1 g L(-1) at pH 3. A UVA/NIO/oxalic acid system led to a low fenuron half-life (60 min). The results were even better when solar light is used (30 min). The variables studied were the doses of iron oxide, of carboxylic acids, the solution pH and the effect of sunlight irradiation. The effects of four carboxylic acids, oxalic, citric, tartaric and malic acids, on the fenuron photodegradation with NIO have been investigated, oxalic acid was the most effective carboxylic acid used at pH 3. A similar trend was observed for the removal of total organic carbon (TOC), 75% of TOC was removed. The analytical study showed many aromatic intermediates, short-chain carboxylic acids and inorganic ion.

Novel Na₂Mo₄O₁₃/α-MoO₃ hybrid material as highly efficient CWAO catalyst for dye degradation at ambient conditions

We report a novel hybrid material Na2Mo4O13/α-MoO3 as highly efficient catalytic wet air oxidation (CWAO) catalyst, which showed the highest ever activity at room temperature and atmosphere pressure for the degradation of cationic red GTL. SEM and TEM analyses indicated that this hybrid catalyst has bamboo-shaped nanofiber morphology. In view of practical applications, the influence of some key parameters including operation temperature, catalyst calcination temperature, and the volume of dye wastewater have been optimized. The mechanism for the superior catalytic performance was investigated. XRD, XPS, and ESR suggested the Na2Mo4O13/α-MoO3 hybrid catalyst possesses more O(2-) ions in the oxygen deficient regions than neat α-MoO3, promoting the formation of active ·OH radicals and resulting in a higher activity. Considering the facile preparation and its superior activity, this novel catalyst is promising for practical dye wastewater treatment.

Non-hydroxyl radical mediated photochemical processes for dye degradation

The UV/diketone processes can degrade dyes faster and more selectively than the UV/H₂O₂ process, due to their non-hydroxyl radical nature.

An Ru(ii)–Fe(iii) bimetallic complex as a multifunctional device for detecting, signal amplifying, and degrading oxalate

A multifunctional device that can monitor the level of pollutants, magnify weak signals, and subsequently degrade pollutants is highly desirable. A new Ru(ii)–Fe(iii) complex—[Ru^II(^tBubpy)(CN)₄]₂–[Fe^III(H₂O)₃Cl]₂·8H₂O (1,^tBubpy = 4,4′-di-tert-butyl-2,2′-bipyridine)—was synthesized and characterized.

Catalytic wet peroxide oxidation of phenol by [C16H33(CH3)3N]4H2SiV2W10O40 catalyst

Under ambient temperature and atmospheric pressure conditions, phenol could be completely oxidized to CO₂ with catalyst [C₁₆H₃₃(CH₃)₃N]₄H₂SiV₂W₁₀O₄₀.

Photodegradation mechanism of sulfadiazine catalyzed by Fe(III), oxalate and algae under UV irradiation

Photodegradation mechanism of sulfadiazine (SD) in a solution containing Fe(III), oxalate and algae were investigated in this study. The results indicated that the degradation of SD was slow in a solution containing Fe(III) or oxalate, whereas it was markedly enhanced when Fe(III) and oxalate coexisted. The optimal pH for formation of *OH was 4; a higher or lower pH resulted in a decrease in formation of OH. A moderate increase of oxalate concentration was beneficial to the formation of *OH and the degradation of SD, and the algae enhanced the degradation rate of SD in a solution containing Fe(III) and oxalate. Also, the degradation rate of SD rapidly decreased at low initial concentrations but slowly decreased at high initial concentrations, and pseudo-first order kinetics described the degradation process of SD well. A possible reaction mechanism in solution containing Fe(III), oxalate and algae was proposed, and attack by *OH was the main pathway of SD degradation in the photocatalytic reaction.

Highly active and enhanced photocatalytic silicon nanowire arrays

Nanoporous and nonporous three-dimensional silicon nanowire arrays (SiNWAs) prepared with metal-assisted chemical etching method were investigated as photocatalysts in dye photodegradation systematically. In comparison with nonporous SiNWAs, nanoporous SiNWAs have higher surface area, larger pore volume, stronger light absorption and better photocatalytic activity. After the HF-treatment, the photocatalytic activity of all kinds of SiNWAs increased significantly and the nanoporous SiNWAs showed excellent stability. The photocatalytic activity of different types of SiNWAs with hydrogen surface termination can be recovered by HF treatment. This study also reveal that the hydrogen terminated surfaces on silicon nanowires (SiNWs) enhance the performance of SiNWAs by increasing their photocatalytic activity.

Electrolytic treatment of methyl orange in aqueous solution using three-dimensional electrode reactor coupling ultrasonics

The treatment of wastewater containing methyl orange was investigated experimentally using a three-dimensional electrode reactor coupling ultrasonics and the effect of ultrasonics on the degradation was studied. The effects of cell voltage, original concentration of methyl orange, pH value and the concentration of electrolyte on the removal efficiency were considered. The experimental results indicated that the removal rate of methyl orange exceeded 99% and the removal of chemical oxygen demand (COD(Cr)) approached 84% under the optimum conditions. Using ultraviolet-visible spectrum analysis, a general degradation pathway for methyl orange was proposed based on the analysis of intermediate compounds. According to the ultraviolet-visible spectral changes during degradation of methyl orange, it can be presumed that the removal of COD(Cr) lags behind the removal of methyl orange because the structure of the benzene ring was more difficult to destroy compared with the azo double bonds.

Preliminary Study on the Photoproduction of Hydroxyl Radicals in Aqueous Solution with Aldrich Humic Acid, Algae and Fe(III) Under High-pressure Mercury Lamp Irradiation

Under a high-pressure mercury lamp (HPML) and using an exposure time of 4 h, the photoproduction of hydroxyl radicals (*OH) could be induced in an aqueous solution containing humic acid (HA). Hydroxyl radicals were determined by high-performance liquid chromatography using benzene as a probe. The results showed that *OH photoproduction increased from 1.80 to 2.74 microM by increasing the HA concentration from 10 to 40 mg L(-1) at an exposure time of 4 h (pH 6.5). Hydroxyl radical photoproduction in aqueous solutions of HA containing algae was greater than that in the aqueous solutions of HA without algae. The photoproduction of *OH in the HA solution with Fe(III) was greater than that of the solution without Fe(III) at pH ranging from 4.0 to 8.0. The photoproduction of *OH in HA solution with algae with or without Fe(III) under a 250 W HPML was greater than that under a 125 W HPML. The photoproduction of *OH in irradiated samples was influenced by the pH. The results showed that HPML exposure for 4 h in the 4-8 pH range led to the highest *OH photoproduction at pH 4.0.

UV-light induced photodegradation of 17alpha-ethynylestradiol in aqueous solutions

The photodegradation of 17alpha-ethynylestradiol (EE2) in aqueous solutions induced by UV-light was preliminarily studied in this paper by means of fluorescence, UV and infrared spectra. The result suggested that EE2 in aqueous solutions underwent photodegradation under irradiation with UV disinfection lamp (lambda = 254 nm, 30 W), but the photodegradation was not observed under high pressure mercury lamp (lambda > or = 365 nm, 250 W). The photodegradation of 1.6-20.0 mg/l EE2 in aqueous solutions at a given initial pH value of 6.8 was pseudo-first order reaction. Increasing the initial concentration of EE2 lowered the photodegradation rate. The photodegradation rate of EE2 reached the lowest value at pH about 5.0, higher pH values of 6.0-8.0 benefited the photodegradation. Ferric ions can promote the photodegradation of EE2 in aqueous solutions at pH value of 2.0-5.0.