In this article, we demonstrate that submicrometer particles with surface-grafted sodium alginate (SA) display enhanced and reversible aggregation/disaggregation properties in aqueous solution. 300 nm silica particles were first functionalized with an aminosilane coupling agent, followed by the grafting of pH-sensitive SA, as confirmed by zeta potential, XPS and FTIR analyses. The SA-modified particles show enhanced aggregation properties at acidic pH compared to unmodified silica, with a 10 times increase in average aggregate diameter. The process is reversible, as the aggregates can be broken and dispersed again when the pH is increased back to 7.0. As a result, the sedimentation rate of SA-modified particles at pH 3.0 is both significantly faster and complete compared to the unmodified particles. This enhanced aggregation is most likely due to the formation of intermolecular hydrogen bonds between neighboring SA-modified particles. This work illustrates how surface-grafted macromolecules of natural origins can be used to tune interparticle interactions, in order to improve separation processes.

This work demonstrates how grafting natural polysaccharides, herein sodium alginate, on a particle surface enhances the separation of Pickering emulsion constituents.

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Tetracycline (TCy) belongs to PPCPs is such an widely used antibacterial drug, which is discharged from urban wastewater treatment plants or agricultural e uents. Due to low metabolism, poor absorption, overuse, and misuse, TCy is considered as threat to environmental and its removal from waste-water is vital. In this research, a novel ionic liquid modi ed magnetic activated carbon nanocomposite (IL@mAC) was synthesized, characterized, and the adsorption e ciency of IL@mAC for removal of TCy was investigated under different operational parameters of pH (3-11); dose of IL@mAC (0.01-0.1 g/50 mL); reaction time (30-240 min), and initial TCy concentration (50-1500 mg/L). The IL@mAC characterization was done using XRD, VSM, SEM-EDX, BET, and FTIR. Results of equilibrium experiment showed that the highest removal e ciency (~ 98%) was obtained using 0.06 g of IL@mAC in 135 min at pH 7 and temperature 303 K. Considering the correlation coe cients (R 2 ) for different adsorption models, it can be deduced that adsorption of TCy onto IL@mAC is better followed by Langmuir (0.9977) in comparison to Freundlich (0.9412), and Temkin (0.9536) models. Furthermore, Langmuir adsorption capacity was observed to be 666.7 mg/g. The regeneration study showed that IL@mAC retained around 85% TCy adsorption e ciency after 6th cycle. Finally, the present study indicates that the IL@mAC is of a high applicability and has extremely high adsorbent capacity to remove TCy from water compared to most of other benchmark adsorbents reported in literature.

In this study hydrogen production from the autothermal reforming (ATR) of glycerol was investigated in a packed bed tubular reactor using nickel-based catalysts with theoretical composition of 5% Ni/Ce0.5Zr0.33M0.16O2−δ, where M is the promoter element selected from Mg, Ca, Y, La, or Gd. The structural, textural, and physicochemical characteristics of the catalysts were investigated using various characterization techniques. The catalytic activity was evaluated in a temperature range from 450 to 700 °C; steam-to-glycerol (S/G) ratio of 6, 9, and 12; and oxygen-to-glycerol (O/G) ratio of 0.2, 0.5, and 0.8 at atmospheric pressure. Among all the catalyst formulations prepared in the current study, 5Ni/CeZrGd exhibited the best catalytic performance and stability compared to the other promoter elements. For 5Ni/CeZrGd catalysts, it was found that, until 600 °C, conversion increased rapidly with the increase in temperature to reach 82 mol % glycerol conversion and more than 70 mol % H2 selectivity, which can be optimal operation conditions for industrial applications. Furthermore, the increase of O/G ratio showed similar trends. Although adding more S/G in the feed did not show any noticeable increase in glycerol conversion, it resulted in lower hydrogen concentration in the reformate product due to the dilution effect of steam.