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Porous hollow carbonaceous microspheres (PHCMs) fabricated from yeast cells by hydrothermal treatment have stimulated interest because of their outstanding chemical and physical properties. Herein, the functionalizations of PHCMs by further coating of α-Fe2O3 nanoparticles onto the surface were carried out. The structure of resulted α-Fe2O3@PHCMs products were characterized by field emission scanning electron microscopy (FE-SEM), energy dispersive spectrometry (EDS), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and BET specific surface area measurements (BET), respectively. Its promising application was evaluated by the Fenton-like degradation of fluorescent whitening agent-VBL from aqueous solutions.<br>In this work, novel α-Fe2O3@porous hollow carbonaceous microspheres (α-Fe2O3@PHCMs) were synthesized through a combination of hydrothermal method and calcinations route and achieved excellent removal efficiency for fluorescent whitening Agent-VBL.<br><br>Display Omitted<br>• The hybrid α-Fe2O3@ porous hollow microspheres (PHCMs) were firstly fabricated. • The formation mechanism of α-Fe2O3@PHCMs microspheres was proposed and verified. • Dithizone played a key role in the synthesis of α-Fe2O3@PHCMs composites. • A favorable removal for the fluorescent whitening agent-VBL were achieved.
Glucose carbon with uniform diameter was successfully anchored by TiO<sub>2</sub> nanoparticles via a facile low-temperature hydrothermal process independent of surfactants or external forces. The resultant TiO<sub>2</sub>@glucose carbon composite (TiO<sub>2</sub>@GCs) was characterized by scanning electron microscopy (SEM) and energy dispersive spectrometry (EDS). The elimination of direct deep blue (DDB) from aqueous solution by adsorption onto TiO<sub>2</sub>@GCs was investigated in the up-flow fixed-bed columns. The effects of the influent concentration (10-30 mg L<sup>−1</sup>), flow rate (3-5 mL min<sup>−1</sup>), bed depth (1.0-2.0 cm) and pH (1.0-9.0) were investigated. Breakthrough time and adsorption capacity of the fixed-bed increased with increasing bed depth, whereas decreased with the increase in initial concentration, bed depth and solution pH values. The experimental data was in good agreement with both Thomas model and Yoon-Nelson model. The employed bed saturated with DDB was readily regenerated through a simple regeneration process with UV irradiation for 1 h. Furthermore, the adsorption-regeneration process was conducted for six cycles and no major decrease of regeneration efficiency was observed for the first three cycles. One possible mechanism for regenerating dye-loaded TiO<sub>2</sub>@GCs was proposed. The verifying experiment found that hydroxyl radicals and superoxide ions significantly affected the regeneration of employed TiO<sub>2</sub>@GCs bed.
To alleviate the adverse effects of pesticide residues on the environment, development of a more safe, economical, and reliable usage approach of pesticides is critically urgent. In the present study, a novel pesticide carrier LA-NSM (lauric acid-modified Nitraria seed meal) with controlled release property was prepared through grafting esterification of lauric acid onto Nitraria seed meal substrates. The structure of the obtained samples was characterized by Fourier-transform infrared spectroscopy, scanning electron microscopy, and contact angle measurements. The results indicated that LA-NSM products had a well-defined hydrophobic surface and irregular holes for efficient loading of pesticide molecules. Deltamethrin (DEL), a representative insoluble pyrethroid insecticide in water, was deliberately selected as the index pesticide to evaluate the loading and releasing efficiency of LA-NSM. The loading capacity of LA-NSM for DEL can reach about 1068 mg/g. pH, humidity of soil, and temperature had a significant influence on controlled release performance of LA-NSM@DEL. Moreover, the releasing kinetics of LA-NSM@DEL composites could be fitted well with the Higuchi model. Overall, the highly hydrophobic property, excellent loading, and controlled release ability of LA-NSM made it a promising candidate in agricultural applications. [ABSTRACT FROM AUTHOR]
Traditional superabsorbent polymers have wide application potential as an adsorbent, but the poor physical and mechanical properties limit their further applications. To tentatively overcome this dilemma, a novel poly(acrylic acid)/poly(vinyl alcohol)/yeast superabsorbent polymers (PAA/PVA/yeast SAPs) with interpenetrating polymer networks (IPNs) were fabricated herein via solution polymerization. The mechanical stability tests showed that the resulting products could desirably resist the destruction of shear flow (<5000 rpm) and load pressure (<3 kg). The effects of yeast content, pH, contact time, initial dye concentration and temperature were systematically studied to evaluate their adsorption properties. Consecutive five cycles of adsorption-desorption indicated that their easy regeneration and reusability. More importantly, the PVA/PAA/yeast SAPs displayed brilliant pH-dependent selective adsorption for dyes in dye mixtures. It is believed hereby that the PAA/PVA/yeast SAPs can be expected to be economically and technically feasible for the scalable treatment of dyes wastewater.
<br>Display Omitted<br>• Conversion of waste buckthorn branches to a value-added bio-carbon product. • Practical adsorbent for removal and destruction of DC contaminants. • Consecutive biosorption and heterogeneous Fenton oxidation regeneration cycles. • Composite biosorbent with β-FeOOH nanoparticles and in-situ catalytic regeneration properties.<br>Akaganeite (β-FeOOH) nanoparticles were successfully anchored on the surface of porous sea buckthorn biocarbon (SBC) via a simple low-temperature hydrothermal process without use of surfactants or external forces. The SBC@β-FeOOH composite was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive spectrometry (EDS). On the basis of characterization methods, a possible mechanism of formation of the SBC@β-FeOOH composite was discussed. The SBC@β-FeOOH composite was used in fixed-bed columns for the effective removal of doxycycline (DC) from an aqueous solution, by the synergistic effect of adsorption and subsequent Fenton-like oxidation reaction, which oxidized the sorbed DC. The effects of inlet DC concentration (22-32 mg/L) feed flow rate (1-3 mL/min) SBC@β-FeOOH bed depth (0.7-1.5 cm) and pH (2-11) on the adsorption breakthrough profiles were investigated. The adsorption process was controlled by the ionic speciation of the adsorbate DC and the available binding sites of SBC@β-FeOOH. It was simulated by the Thomas and Yoon-Nelson models under different conditions. The bed of SBC@β-FeOOH saturated with DC was readily regenerated, in situ, by a heterogeneous Fenton-like oxidation reaction. The synergistic effect resulting from the biosorption nature of SBC and the catalytic oxidation properties of the supported β-FeOOH nanoparticles results in a new promising composite material for water treatment and purification.
NSM-<i>g</i>-P(MMA-<i>co</i>-BA) resin with super oil-absorbent capability was prepared by grafting co-polymerization using Nitraria seeds meal as filler, methyl-meth-acrylate (MMA) and butyl-acrylate (BA) as monomers, <i>N,N′</i>-methylene-bis-acrylamide (MBA) as crosslinker and peroxide-benzoyl (BPO) as initiator. The structure of obtained products was analyzed using Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM), respectively. The oil absorbency, reusability, oil-retention capacity, thermodynamics, and the removal of oil from the surface of 0.9 wt% NaCl solutions were examined further. The results showed that NSM-<i>g</i>-P(MMA-<i>co</i>-BA) can absorb lubrication up to 29.6 times of its weight, 24.3 times for colza oil, 22.7 times for diesel, and 21 times for gasoline. The exhausted NSM-<i>g</i>-P(MMA-<i>co</i>-BA) can be recollected and recovered through extraction or drying approach. More importantly, the oil sorption capacity of recovered NSM-<i>g</i>-P(MMA-<i>co</i>-BA) only has a slight decline after six sorption cycles. The thermodynamic studies indicated that adsorption procedure with complex physical and chemical sorption is spontaneous and exothermic. In general, the present composite resins have exhibited potential applications in cleanup of oil spills because of their good hydrophobicity, lipophilicity, and excellent network structure. Also, the findings of this study might provide a convenient and economic method for fast and selective removal of oil from surface of wastewater. POLYM. COMPOS., 39:1051-1063, 2018. © 2016 Society of Plastics Engineers
<b>Caragana korshinskii</b> Kom. (CK), one of afforestation tree species, is widely planted in northwest region of China. To compare the constituents as references for further utilization of CK, <b>C. microphyll</b> Lam. (CM) and <b>C. jubata</b> L. (CJ), been used as traditional Chinese medicine, were taken into consideration. To obtain more information on CK for further utilization, a sensitive and stable pre-column derivatization method for the analysis of fatty acids (FAs) was established using a novel labeling reagent 2-(5H-benzo[a]-carbazol-11(6H)-yl)ethyl hydrazine-carboxylate (BCEHC) by HPLC with fluorescence detector. The derivatives exhibit predominant fluorescence property at excitation and emission wavelengths of 330 nm and 380 nm, respectively. 16 derivatives of FAs including 13 saturated FAs and 3 unsaturated FAs are separated on a reversed-phase column with gradient elution within 30 min. The validation of method indicated that all FAs were given excellent linear responses with good linear coefficient of correlation being equal to or greater than 0.9985. The limits of detection (LODs) at a signal-to-noise ratio of 3 varied from 63.12 to 116.21 ng L−1. The developed method was successfully applied to determine the contents of free FAs (FFAs) in flowers, leaves and bark of CK and the samples were extracted by a green and simple method of gas purge microsyringe extraction. The results show that the contents of linoleic acid and linolenic acid are high in flowers and leaves while the bark is rich in linoleic acid. The total content of FFAs in all parts of CK is higher than that of CM. The distribution of FFAs in plants is obviously different even in the congeneric among different species.
• Extracts from <b>Lycium ruthenicum</b> Murr. fruit were obtained by UAE. • Phenolic compounds and antioxidant activities of obtained extracts were simultaneously optimized by RSM. • Optimum parameters: time 30 min, power 100 W, solvent-sample ratio 40 mL/g, ethanol 33%. • The extracts contained phenolic acids, identified and quantified by HPLC.<br><b>Lycium ruthenicum</b> Murr. (LR) is a functional food that plays an important role in anti-oxidation due to its high level of phenolic compounds. This study aims to optimize ultrasound-assisted extraction (UAE) of phenolic compounds and antioxidant activities of obtained extracts from LR using response surface methodology (RSM). A four-factor-three-level Box-Behnken design (BBD) was employed to discuss the following extracting parameters: extraction time (<b>X</b> 1), ultrasonic power (<b>X</b> 2), solvent to sample ratio (<b>X</b> 3) and solvent concentration (<b>X</b> 4). The analysis of variance (ANOVA) results revealed that the solvent to sample ratio had a significant influence on all responses, while the extraction time had no statistically significant effect on phenolic compounds. The optimum values of the combination of phenolic compounds and antioxidant activities were obtained for <b>X</b> 1 = 30 min, <b>X</b> 2 = 100 W, <b>X</b> 3 = 40 mL/g, and <b>X</b> 4 = 33% (v/v). Five phenolic acids, including chlorogenic acid, caffeic acid, syringic acid, <b>p</b>-coumaric acid and ferulic acid, were analyzed by HPLC. Our results indicated that optimization extraction is vital for the quantification of phenolic compounds and antioxidant activity in LR, which may be contributed to large-scale industrial applications and future pharmacological activities research.
Glucose carbon microspheres have been widely used for wastewater treatment as adsorbent owing to their strong adsorption capacity, but for large-scale applications, the glucose carbon microspheres are inconvenient to be recycled from aqueous suspension due to their good suspendability. Moreover, the primitive nature of small particle size, large specific surface area and high surface energy of glucose carbon microspheres make them prone to aggregate and thus, disperse no-effectively for the other extended application. To solve this dilemma, polyester (PET) fibers decorated with glucose carbon microspheres (GC@PFs) were herein fabricated by one-step hydrothermal carbonization with acrylic acid as a coupling agent. The products were characterized by Fourier Transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), Boehm titration, X-ray diffraction (XRD), Thermo-gravimetric Analysis (TG), Scanning Electron Microscope (SEM) and zeta potential respectively. The experimental results showed that a large amount of glucose carbon microspheres were evenly dispersed on the surface of carboxyl activated polyester fibers with uniform particle diameter, and the composite fibers showed desirable adsorption ability of cationic dyes for its more negative zeta potential. The dye adsorption isotherm follows Langmuir model and pseudo-second-order kinetic model better. Remarkably, the adsorbent has an excellent recyclability for maintaining a high removal rate (>85%) to dye even after 10 cycles.<br>• Glucose carbon microspheres were evenly distributed on the PET fibers surface that solved the problem of easy aggregation. • The polyester fibers were firstly decorated with glucose carbon microspheres through one-step hydrothermal carbonization. • Acrylic acid maintained the integrity of PET fabric and introduced a quite number of carboxyl groups on the PET surface. • The surface decorated composite material possessed good adsorption property and easy recovery performance. • The glucose carbon microspheres decorated polyester fibers showed a highly selective adsorption for the cationic dyes.
<br>Display Omitted<br>• A new protocol of synchronous determination of phenolic acids (PAs) was proposed by RP-HPLC-UV with double-wavelength. • The validated results demonstrated that the proposed method was feasible to determine PAs in plant samples. • The protocol was applied for analysis PAs in <b>Caragana korshinskii</b> Kom. which was mainly rich in chlorogenic acid, vanillic acid, caffeic acid and rosmarinic acid. • Total content of PAs in leaves was the highest compared with that of flowers and bark.<br>The utilization of <b>Caragana korshinskii</b> Kom. (CK) is currently concentrated on its ecological and fuel functions. Little attention has been devoted to the analysis of their phenolic acid (PA) components. To obtain more data for further utilization of CK, a new analysis protocol was tested to determine PAs synchronously by RP-HPLC-UV with double-wavelength (280 nm and 320 nm) detection. Specifically, separation of PA components was performed on a Hypersil Gold C18 reverse phase column with gradient elution. A four-factor-three-level Box-Behnken design was implemented for optimization of PA extraction. The results demonstrated that CK were rich primarily in chlorogenic acid, vanillic acid, caffeic acid and rosmarinic acid. The total content of PAs in CK leaves was the highest compared with its other parts. The distribution of total flavonoid content of CK was leaves > flowers > bark, while that of the total phenolic content of CK was flowers > leaves > bark.
A new triterpenoid, namely myricarin C (compound 1), together with three known compounds myricarin A (compound 2) and myricarin B (compound 3), 3α-hydroxy-D-friedoolean-14-en-28-oic acid (compound 4), was isolated from the overground part of Myricaria squamosa. Compound 2 and compound 3 existed in the solution by the form of cis-trans isomers. Their structures were elucidated by means of extensive spectroscopic methods, including 1D-NMR, 2D-NMR, and HR-ESI-MS. The antioxidant properties of all compounds were calculated based on the DPPH radical scavenging activities. Results showed that myricarin A and myricarin C had general antioxidant activities with EC50 values of 40.90 μg/ml, 42.22 μg/ml, respectively, compared to the control, rutin (5.17 μg/ml). The EC50 values of myricarin B was 195.81 μg/ml. Compound 4 had no antioxidant activities.
Anthocyanins are the main compounds in Nitraria tangutorun Bobr. The enrichment and purification of anthocyanins on macroporous resins were investigated. Regarding anthocyanin purification, static adsorption and desorption were studied. The optimal experimental conditions were the following: resin type: X-5; static adsorption time: 6h; desorption solution: ethanol-water-HCl (80:19:1, V/V/V; pH 1); desorption time: 40min. Furthermore, the in vitro and in vivo biological activities of the anthocyanins were evaluated. The anthocyanins showed ideal scavenging effects on free radicals in vitro, especially on 1,1-diphenyl-2-picrylhydrazyl (DPPH) and hydroxyl free radical (OH). In the animal experiment, blood lipid metabolism of hyperlipidemia rats was regulated by anthocyanin contents. The superoxide dismutase (SOD) activity and the total antioxidant capacity (TAC) of hyperlipidemia rats were also improved by anthocyanins. These results showed that anthocyanins from N. tangutorun Bobr. fruits had potential biological activities in vivo as well as in vitro.