The Coffee Residues and the Esparto Fibers as a Lignocellulosic Material for Removal of Dyes from Wastewater by Adsorption

Biosorption onto lignocellulosic products such as coffee residues and esparto fibers in natural and modified forms have been identified as a potential alternative to the existing biosorbents applied for dye removal from wastewater. The efficiency of each material has been discussed with respect to the operating conditions and the chemical modifications. The investigated thermodynamics and kinetics studies were exposed also in terms of equilibrium isotherms and fitted kinetic models. Moreover, the crucial role of the chemical structures of the cellulosic fibers as an affecting factor on the mechanism of the adsorption process was evaluated and compared. The different treatment methods showed an improvement in terms of removal and maximum adsorption capacity. In fact, in some cases the removal capacity can be increased to 99% and the maximum adsorption capacity can reach 67 mg/g. On the other hand, the different investigations showed that the study data fitted to the known model such as Langmuir isotherm and pseudo-second-order kinetic

Adsorption of congo red dye from aqueous solutions by prepared activated carbon with oxygen-containing functional groups and its regeneration

This study investigates the potential use of activated carbon prepared from coffee waste (CW) as an adsorbent for the removal of congo red dye from aqueous solution. The oxygen-containing groups of activated carbon prepared from CW play an important role in dyes ions adsorption onto activated carbon prepared from CW. The activated carbon is characterized by scanning electron microscopy and Fourier transform infrared (FTIR) spectroscopy. Adsorption experiments were carried out as batch studies at different contact time, pH, and initial dye concentration. The dye adsorption equilibrium was attained after 120 min of contact time. Removal of dye in acidic solutions was better than in basic solutions. The adsorption of dye increased with increasing initial dye concentration. The equilibrium data were revealed that Langmuir model was more suitable to describe the congo red adsorption and demonstrated excellent reusability potential with desorption greater than 90% throughout six consecutive adsorption–desorption cycles. Experimental data founded that kinetics followed a pseudo-second-order equation. Thermodynamic study showed that the adsorption was a spontaneous and exothermic process. According to the FTIR analyses, hydrogen bonding and electrostatic interactions between dyes and oxygen-containing functional groups on activated carbon prepared from CW are dominant mechanisms for dye adsorption

Solid Lipid Nanoparticle-Based Calix[n]arenes and Calix-Resorcinarenes as Building Blocks: Synthesis, Formulation and Characterization

Solid lipid nanoparticles (SLNs) have attracted increasing attention during recent years. This paper presents an overview about the use of calix[n]arenes and calix-resorcinarenes in the formulation of SLNs. Because of their specific inclusion capability both in the intraparticle spaces and in the host cavities as well as their capacity for functionalization, these colloidal nanostructures represent excellent tools for the encapsulation of different active pharmaceutical ingredients (APIs) in the area of drug targeting, cosmetic additives, contrast agents, etc. Various synthetic routes to the supramolecular structures will be given. These various routes lead to the formulation of the corresponding SLNs. Characterization, properties, toxicological considerations as well as numerous corresponding experimental studies and analytical methods will be also exposed and discussed

Calix-arene silver nanoparticles interactions with surfactants are charge, size and critical micellar concentration dependent

International audienc

Molecular recognition of nucleobases and amino acids by sulphonato-calixnaphthalene-capped silver nanoparticles.

International audienceThe plasmon resonances of sulphonato-calixnaphthalene-capped silver nanoparticles have been used to study the complexation of the nanoparticles with nucleobases and amino acids. Only in the case of the nanoparticles capped with oxacalix[4]naphthalenesultone, does complexation of both nucleobases and certain amino acids occur. The complexation of the aromatic amino acids, phenylalanine and tryptophan, has previously not been observed for calixarene-capped silver nanoparticles.The plasmon resonances of sulphonato-calixnaphthalene-capped silver nanoparticles have been used in the study of complexation of the nanoparticles with nucleobases and amino acids

Molecular recognition of nucleobases and amino acids by sulphonato-calixnaphthalene-capped silver nanoparticles.

International audienceThe plasmon resonances of sulphonato-calixnaphthalene-capped silver nanoparticles have been used to study the complexation of the nanoparticles with nucleobases and amino acids. Only in the case of the nanoparticles capped with oxacalix[4]naphthalenesultone, does complexation of both nucleobases and certain amino acids occur. The complexation of the aromatic amino acids, phenylalanine and tryptophan, has previously not been observed for calixarene-capped silver nanoparticles.The plasmon resonances of sulphonato-calixnaphthalene-capped silver nanoparticles have been used in the study of complexation of the nanoparticles with nucleobases and amino acids