Adsorptive removal of PPCPs by biomorphic HAP templated from cotton

Preparatiοn οf pοrοus hydrοxyapatite-metakaοlin geοpοlymer granules fοr adsοrptiοn applicatiοns using pοlyethylene glycοl as pοrοgen agent and sοdium dοdecyl sulfate as aniοnic surfactant

This study investigated the elaboration of novel porous absorbent granules by mixing powdered hydroxyapatite, metakaolin, sodium metasilicate, polyethylene glycol, and sodium dodecyl sulfate (SDS), an anionic surfactant. The effect of sodium dodecyl sulfate (SDS) was then studied by introducing it as a powder to the powdered mixture or dissolved into the granulation fluid. Characterization of the granules indicated that the incorporation of SDS dissolved in the granulation fluid into the G-PEG granules improved their specific surface area (97.9 m2/g) and porosity, resulting in a synergistic increase in the adsorption of crystal violet and methylene blue dyes compared to G-PEG granules and hydroxyapatite or metakaolin geopolymer alone. Moreover, the granules exhibited satisfactory compressive strength of 0.81 MPa, making them suitable for large-scale adsorption columns. Finally, the regeneratiοn prοcess οf the granules was modeled and optimized by using surface response methodology based on Box-Behnken design. The granules cοuld be regenerated fοr eight cycles under οptimum cοnditiοns οf acetic acid cοncentratiοn οf 0.72 mοl/L, a temperature οf 323 K, and a cοntact time οf 173.22 min, withοut a significant lοss in the adsοrptiοn capacity οr degradatiοn οf the granules. These results suggest that the pοrοus granules prepared in this study have pοtential tο be used in industrial wastewater treatment.

Hydroxyapatite-based composites: Excellent materials for environmental remediation and biomedical applications

Given their unique characteristics and properties, Hydroxyapatite (HAp) nanomaterials and nanocomposites have been used in diverse advanced catalytic technologies and in the field of biomedicine, such as drug and protein carriers. This paper examines the structure and properties of the manufactured HAp as well as a variety of synthesis methods, including hydrothermal, microwave-assisted, co-precipitation, sol-gel, and solid-state approaches. Additionally, the benefits and drawbacks of various synthesis techniques and ways to get around them to spur more research are also covered. This literature discusses the various applications, including photocatalytic degradation, adsorptions, and protein and drug carriers. The photocatalytic activity is mainly focused on single-phase, doped-phase, and multi-phase HAp, while the adsorption of dyes, heavy metals, and emerging pollutants by HAp are discussed in the manuscript. Furthermore, the use of HAp in treating bone disorders, drug carriers, and protein carriers is also conferred. In light of this, the development of HAp-based nanocomposites will inspire the next generation of chemists to improve upon and create stable nanoparticles and nanocomposites capable of successfully addressing major environmental concerns. This overview's conclusion offers potential directions for future study into HAp synthesis and its numerous applications.

Facile preparation of 3D GO with caffeic acid for efficient adsorption of norfloxacin and ketoprofen

In this paper, a simple and green method was developed to fabricate a three-dimensional (3D) graphene-based material with the assistance of caffeic acid (CA). The prepared 3D graphene displayed fast and high sorption for norfloxacin (NOR) and ketoprofen (KP). Their adsorption equilibrium was achieved within 12 h for NOR and KP, which was attributed to their fast diffusion in the porous structure of the 3D graphene. The maximum adsorbed amount of this adsorbent was 220.99 mg/g for NOR and 125.37 mg/g for KP according to the Langmuir model at pH 6.6, 298 K. In the competitive adsorption of six pharmaceuticals, the organic compounds in the form of cations are preferentially adsorbed on the adsorbent. The co-existing organic compounds in the actual wastewater do not seriously inhibit the adsorption of NOR and KP. This study provides the theoretical basis for the facile and low-cost preparation of high-performance 3D graphene adsorbents. The results of this study demonstrate the potential utility of 3D graphene as a very effective adsorbent for pharmaceuticals removal from contaminated water.

The Systematic Adsorption of Diclofenac onto Waste Red Bricks Functionalized with Iron Oxides

In this study, waste red bricks were incorporated with iron oxides (goethite and hematite) and used for the removal of diclofenac (DCF) from aqueous solutions. The prepared waste red bricks were systematically characterized by XRF, XRD, BET, and SEM. The batch experiments were systematically conducted by investigating the adsorption kinetics, isotherms, thermodynamics, pH, and ionic strength effect. Results showed that the incorporation of iron oxides could enhance the adsorption capacity of DCF onto waste bricks, while the increased effect of hematite was better than goethite. DCF was adsorbed rapidly onto waste bricks, and the adsorption kinetic fitted the pseudo-second-order model perfectly, which could be attributed to the strong interaction between DCF and iron oxides. The increasing pH values decreased the adsorption capacity greatly, which may be due to the electrostatic repulsive interactions. The adsorption of DCF onto waste bricks was an exothermic reaction, and the adsorption isotherms fitted well with the Langmuir model. This study offers new guidelines for the utilization of construction waste, and shows useful methods for the elimination of micropollutants from aqueous solution.