Removal Efficiency of Lipid-regulating Drug Clofibric Acid from the Aquatic Environment by Calcined Anionic Clay ZnAl-CO3

Clofibric acid (CA) is widely used as regulator of lipid levels in blood; it is considered one of the residual drugs that have a high persistence in the aquatic environment. After wastewater treatment, only a small amount of CA can be removed. The aim of this work was to investigate the reduction of CA in contaminated wastewater using calcined anionic clay ZnAl-CO3, which was chosen for its higher adsorption capacity, recyclability, and non-regeneration of sludge. The maximum retention amount, Qm, exceeded 2220 mg g–1, and the value of DH° suggested a physical process. The removal rate achieved 90 %, and the remaining quantity was widely below the tolerance thresholds. Retention was achieved by hydrogen bonds and electrostatic interactions between the adsorbate molecules. Recycling tests clearly suggested that this material is recyclable, promising, and very effective compared to other adsorbents. This retention contributes to the attenuation of persistent lipid regulator. This work is licensed under a Creative Commons Attribution 4.0 International License

Water reuse after removing a textile dye methyl orange using a recyclable hydrotalcite material

Hydrotalcite type material based on zinc, aluminum and carbonates was synthesized by coprecipitation method and its derived calcined at 500°C (CHT) was used to remove the textile dye methyl orange (MO). This adsorbent has a great potential for removing pollutants from aqueous solutions without generating sludge. Adsorption was performed in batch experiments. A rapid process of retention confirmed by kinetics reflects a high affinity between CHT material and MO dye. The adsorption isotherms follow the Langmuir model (L type). The results of several techniques suggest the intercalation of the pollutant between the hydrotacite sheets reconstructed from mixed oxides with a gallery of 2.35 nm. The retention capacity reaches 2500 mg/g with a removal rate of 100% for an optimum mass ratio MO/CHT of 0.3. After the recycling studies the material CHT justify its recyclability and confirms its efficiency for eliminating such pollutant

Study of the adsorption process of textile dye AG1 by a mixed oxide derivative of anionic clay

Layered double hydroxides (LDH) are anionic clays with high anion exchange capacities. Calcination of LDH increases significantly their retention capacities. In the present study, calcined products (CLDH) were obtained by heating [Zn2-Al-CO3] at 500°C. The adsorption of the textile dye Acid Green 1 (AG1) by CLDH was performed at different pH values, the textile dye-adsorbent contact time and mass ratio AG1/CLDH. The equilibrium at room temperature is reached after 24 h, this is confirmed by rapid kinetic modeling of the experimental data by the pseudo-second order model.The adsorption is described by Langmuir-type isotherm. The study of adsorption isotherms, comparison with the retention of a carbonated phase of calcined and uncalcined, reveals that the first could be a good candidate for trapping such pollutants. Characterization of the CLDH solids, both fresh and after removal of AG1 by X-ray diffraction and infrared spectroscopy shows that the adsorption is also enhanced by reconstruction of a matrix hydrotalcite intercalated by AG1 at high concentration.The removal of textile dye in anionic form by CLDH gave satisfactory results. Under optimum conditions, the retention is total (100%) when the weight ratio AG1/CLDH is between 0.38 and 0.68. Retention capacity reached 800 mg/g

Specific Binding and Mineralization of Calcified Surfaces by Small Peptides

Several small (<25aa) peptides have been designed based on the sequence of the dentin phosphoprotein, one of the major noncollagenous proteins thought to be involved in the mineralization of the dentin extracellular matrix during tooth development. These peptides, consisting of multiple repeats of the tripeptide aspartate-serine-serine (DSS), bind with high affinity to calcium phosphate compounds and, when immobilized, can recruit calcium phosphate to peptide-derivatized polystyrene beads or to demineralized human dentin surfaces. The affinity of binding to hydroxyapatite surfaces increases with the number of (DSS)n repeats, and though similar repeated sequences—(NTT)n, (DTT)n, (ETT)n, (NSS)n, (ESS)n, (DAA)n, (ASS)n, and (NAA)n—also showed HA binding activity, it was generally not at the same level as the natural sequence. Binding of the (DSS)n peptides to sectioned human teeth was shown to be tissue-specific, with high levels of binding to the mantle dentin, lower levels of binding to the circumpulpal dentin, and little or no binding to healthy enamel. Phosphorylation of the serines of these peptides was found to affect the avidity, but not the affinity, of binding. The potential utility of these peptides in the detection of carious lesions, the delivery of therapeutic compounds to mineralized tissues, and the modulation of remineralization is discussed

Glucuronic acid and phosphoserine act as mineralization mediators of collagen I based biomimetic substrates.

Contains fulltext : 88467.pdf (Publisher’s version ) (Closed access)Glucuronic acid (GlcA) and phosphoserine (pS) carrying acidic functional groups were used as model molecules for glycosaminoglycans and phosphoproteins, respectively to mimic effects of native biomolecules and influence the mineralization behaviour of collagen I. Collagen substrates modified with GlcA showed a stable interaction between GlcA and collagen fibrils. Substrates were mineralized using the electrochemically assisted deposition (ECAD) in a Ca(2+)/H( x )PO (4) ((3-x)) electrolyte at physiological pH and temperature. During mineralization of collagen-GlcA matrices, crystalline hydroxyapatite (HA) formed earlier with increasing GlcA content of the collagen matrix, while the addition of pS to the electrolyte succeeded in inhibiting the transformation of preformed amorphous calcium phosphate (ACP) to HA. The lower density of the resulting mineralization and the coalesced aggregates formed at a certain pS concentration suggest an interaction between calcium and the phosphate groups of pS involving the formation of complexes. Combining GlcA-modified collagen and pS-modified electrolyte showed dose-dependent cooperative effects.1 februari 201