Biosorption of azo dyes by raspberry-like Fe3O4@yeast magnetic microspheres and their efficient regeneration using heterogeneous Fenton-like catalytic processes over an up-flow packed reactor

Raspberry-like Fe3O4@yeast composite microspheres, whose properties integrate the biosorption features of yeast cells with the excellent magnetic and catalytic properties of Fe3O4 nanoparticles were synthesized by a simple electrostatic-interaction-driven self-assembly heterocoagulation. They were successfully applied in an up-flow packed column for the removal of the model water contaminant methylene blue dye (MB) by consecutive bioadsorption-heterogeneous Fenton oxidation cycles. The as-synthesized Fe3O4@yeast composites were characterized by field emission scanning electron microscopy (FE-SEM), energy-dispersive spectroscopy (EDS), powder X-ray diffraction (XRD) and Fourier transform infrared (FT-IR) spectroscopy. The adsorption process was controlled by the electrostatic interactions between the adsorbent and contaminant. The adsorbent is suitable for the adsorption of positively charged compounds at mildly acidic pH, neutral and alkaline pH, with the highest performance observed at alkaline pH. The experimental breakthrough curves measured at different influent MB concentration, flow rate, bed height and pH were modeled by the Yoon-Nelson model. The in-situ regeneration of the contaminant-loaded Fe3O4@yeast microspheres and their reuse in multiple cycles was demonstrated by triggering the heterogeneous Fenton-like reaction catalyzed by the supported magnetite. The raspberry-like Fe3O4@yeast magnetic microsphere should be a promising and practical adsorbent for removal and destruction of positively charged organic compounds in wastewater

A novel and sensitive method for determining vitamin B3 and B7 by pre-column derivatization and high-performance liquid chromatography method with fluorescence detection - Fig 5

<p>The 3D response surface of peak area affected by varying derivatization temperature and time(a), varying derivatization temperature and EDC dosage (b), derivatization time and EDC dosage (c).</p

Novel Fabrication of Biodegradable Superabsorbent Microspheres with Diffusion Barrier through Thermo-Chemical Modification and Their Potential Agriculture Applications for Water Holding and Sustained Release of Fertilizer

Synergistic utilization of water and fertilizer has vital contribution to the modern production of agriculture. This work reports on a simple and facile strategy to prepare biodegradable yeast/sodium alginate/poly­(vinyl alcohol) superabsorbent microspheres with a diffusion barrier merit by thermo-chemical modification route. The integrated performances, including water absorbency, water retention, water evaporation ratio, leaching loss control, sustained-release behaviors, and degradation in soil, were systematically investigated. The results revealed that the modified microspheres were a triumphant water and fertilizer manager to effectively hold water and control the unexpected leakage of fertilizer for sustained release. Therefore, this work provides a promising approach to ameliorate the utilization efficiency of water and fertilizer in potential agriculture applications

Linear range, correlation coefficient, precision, accuracy, quantitative limits, detection limits and repeatability.

<p>Linear range, correlation coefficient, precision, accuracy, quantitative limits, detection limits and repeatability.</p

A Near-Infrared and Temperature-Responsive Pesticide Release Platform through Core–Shell Polydopamine@PNIPAm Nanocomposites

Controlled stimuli-responsive release systems are a feasible and effective way to increase the efficiency of pesticides and help improve environmental pollution issues. However, near-infrared (NIR)-responsive systems for encapsulation of pesticides for controlling release have not been reported because of high cost and load ability of conventional NIR absorbers as well as complicated preparation process. Herein, we proposed polydopamine (PDA) microspheres as a photothermal agent owing to their abundant active sites, satisfactory photothermal efficiency, low cost, and easy fabrication, followed by capping with a PNIPAm thermosensitive polymer shell. In this core–shell PDA@PNIPAm hybrid system, the PDA core provided excellent temperature and NIR-light sensitivity as well as high loading capacity, while the PNIPAm applied as both a thermosensitive gatekeeper and a pesticide reservoir. The structure of the PDA@PNIPAm nanocomposites was characterized by transmission electron microscopy, scanning electron microscopy, Fourier transform infrared spectroscopy, ultraviolet–visible spectroscopy, dynamic light scattering, and thermogravimetric analysis; the results showed that the nanocomposites had a well-defined core–shell configuration for efficient loading of small pesticide molecules. Moreover, the core–shell PDA@PNIPAm nanocomposites exhibited high loading capacity and temperature- or NIR-controlled release performance. Overall, this system has significant potential in controlled drug release and agriculture-related fields as a delivery system for pesticides with photothermal responsive behavior

The synthesis procedure of AEAO.

<p>The synthesis procedure of AEAO.</p

Estimated regression coefficients for the quadratic polynomial model and ANOVA for the experimental results in the optimization of flavonoids extractions.

<p>Estimated regression coefficients for the quadratic polynomial model and ANOVA for the experimental results in the optimization of flavonoids extractions.</p

Comparisons of the proposed method with previously reported methods.

<p>Comparisons of the proposed method with previously reported methods.</p

The extraction process of tea samples.

<p>The extraction process of tea samples.</p

Main content of VB3 and VB7 in the tea.

<p>Main content of VB3 and VB7 in the tea.</p