Ultrasound-assisted formation of composite materials from fish scale waste hydroxyapatite in the presence of gamma-irradiated chitosan for the removal of malachite green

The fish processing sector produces millions of tons of trash annually-a biologically dangerous substance that could eventually turn into a source of pathogenic contamination. This work successfully shows how to extract tilapia fish scale hydroxyapatite with ultrasonic assistance and modify it using gamma-irradiated chitosan to remove malachite green from water samples. The prepared adsorbent was characterized by Fourier transform infrared spectroscopy, X-ray diffraction, X-ray fluorescence, scanning electron microscopy, energy dispersive spectroscopy, transmission electron microscopy, thermogravimetric analysis and dynamic light scattering. Isotherm modeling was employed to investigate the sorption process of malachite green. The results revealed that the adsorbent could be used to remove malachite green in aqueous media, with a maximum adsorption capacity of 285.7 mg g-1. A pseudo-second-order model was then fitted to the kinetic data. The R 2 value of 0.9851 obtained indicated that the adsorption behavior was consistent with the Langmuir model. Analysis of the computed thermodynamic parameters revealed that the adsorption of the dye was a spontaneous and exothermic process. Proper waste management practices not only ensure environmental responsibility but also contribute to positive community relations by minimizing the impact on the local environment.

Fabrication of calix[4]arene/polyurethane for the adsorptive removal of cationic dye from aqueous solutions

Calix[4]arene/polyurethane (C4PU) has been synthesized and characterized as an alternative adsorbent for the adsorption of methylene blue (MB) and malachite green (MG) dyes from the aqueous solution. C4PU was synthesized by reacting p-tert-butyl calix[4]arene with hexamethylene diisocyanate (HMDI) as the cross-linking agent. Different polymer ratios were synthesized, and C4PU-4 shows better adsorption than other ratios. The polymer was characterized by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), Brunauer-Emmett-Teller (BET) analysis, and point of zero charges (pHPZC). The isotherms and kinetics of the adsorption of MB and MG were studied under a range of experimental conditions, including pH, adsorbent dosage, initial dye concentration, and contact time. The adsorption was determined by the adsorption percentage of MB and MG dyes from the solution. The Langmuir isotherm model best describes the adsorption process for both dyes, and it follows a pseudo-second-order kinetic model, with the maximum adsorption capacity (qmax) of MB and MG, respectively, was found to be 1.991 mg·g-1 and 2.240 mg·g-1.

Adsorption removal of malachite green dye from aqueous solution

In this review, the state of the art on the removal of malachite green dye from aqueous solution using adsorption technique is presented. The objective is to critically analyze different adsorbents available for malachite green dye removal. Hence, the available recent literature in the area is categorized according to the cost, feasibility, and availability of adsorbents. An extensive survey of the adsorbents, derived from various sources such as low cost biological materials, waste material from industry, agricultural waste, polymers, clays, nanomaterials, and magnetic materials, has been carried out. The review studies on different adsorption factors, such as pH, concentration, adsorbent dose, and temperature. The fitting of the adsorption data to various models, isotherms, and kinetic regimes is also reported.

New lignin-based polyurethane foam for wastewater treatment

Utilization of renewable feedstock for the development of alternative materials is rapidly increasing due to the depletion of petroleum resources and related environmental issues.