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ADSORPTION OF BASIC YELLOW 28 (BY 28) AND ACID YELLOW 23 (AY 23) DYES ONTO CHITIN

100%

Filipkowska U. , Kuczajowska-Zadrożna M. , Jóźwiak T. , Szymczyk P. , Kaczyński A.

Progress on Chemistry and Application of Chitin and its Derivatives

2015

tom 20

34-42

The present study investigated the sorption of Basic Yellow 28 (BY 28) and Acid Yellow 23 (AY 23) by chitin flakes. The study determined the influence of pH value on adsorption effectiveness and the adsorption capacity of chitin flakes. The results were described with Freundlich, Langmuir, Sips and double Langmuir isotherms. Similar values of adsorption capacities were achieved for both tested dyes using Langmuir, Sips and Langmuir2 models, i.e. 16.804, 17.740 and 18687 mg/g d.m. for BY28 as well as 24.195, 27.930 and 24.196 mg/g d.m. for AY23, respectively. The isotherms were compared with the use of average relative error (ARE) of approximation. In the case of both dyes, the best fit to experimental data was achieved with the use of tri-parametric Sips equilibrium isotherm, which was indicated by ARE values of 3.10% (BY 28) and 5.26% (AY 23).

Removal of Hexavalent Chromium from Aqueous Solution by the Pod of Acacia gerrardii

100%

Abdulaziz M. A. , Bakri A. A. , Al-Zahrani S. A. , Al-Zahrani M. S. , Al-Lehebi A. N. , Banjar F. M. , Nabag M. I.

Polish Journal of Chemical Technology

2019

tom Vol. 21, nr 2

14--19

This study aims at investigating the potential of Acacia gerrardii pod for the removal of Cr(VI) in batch system. Effect of solution pH, biosorbent dosage, initial concentration of Cr(VI), contact time on the removal process was examined. Complete removal of hexavalent chromium was achieved at pH values 1.0 and 2.0 whereas maximum removal of total chromium was obtained at pH of 3.0. The study showed that the biosorption and bioreduction mechanisms were involved in the removal process. The time required for complete removal of Cr(VI) using the pod of Acacia gerrardii was shortened with an increase in biomaterial dosage and decrease in Cr(VI) concentration. Kinetic data was well described using Park kinetic model. Freundlich isotherm model adequately fitted the equilibrium data indication multilayer adsorption of total chromium on the surface of biomaterial. The pod of Acacia gerrardii could be used efficiently for the removal of hexavalent chromium from aqueous solutions.

Study on Wastewater Treatment in the Textile Industry by Adsorption of Reactive Red 141 Dye Using a Phosphogypsum/ Vanadium Composite Developed from Phosphate Industry Waste

100%

Chajri F. Z. , Bensemlali M. , Hatimi B. , Sanad A. , Joudi M. , Abdellatif A. , Siniti M. , Bakasse M. , Baraket A. , Nasrellah H.

tom Vol. 25, iss. 7

46--62

A novel method has been explored based on the recovery of two industrial wastes V2 O5 and phosphogypsum from the fertilizer production industry, which also provide a significant challenge due to their toxicity and environmental impact. To solve the problem of these two harmful wastes, these residues have been transformed into valuable resources, by the elaboration of Nanoparticles vanadate-hydroxyapatite (NPs-HAP/VAP) adsorbent, contributing a sustainable solution without requiring expensive or highly skilled work. This comprehensive investigation explores the adsorption of the reactive red 141 dye (RR 141) on Ca10 (VO4 ) x (PO4 ) 6−x (OH) 2 , with (xi = 0, 1.5, 3, 4.5, and 6). Using a Centered composite design (CCD), several parameters influencing the adsorption process were examined. The optimal adsorption capacity is 50 mg. g – 1 under optimal conditions 57.5 mg of the adsorbent dose, 152.5 mgL-1 for the RR 141, pH 8, 92.5 minutes of contact time, and incorporation ratio of 4.5 with an R2 of 0.99. These results reinforce the effectiveness of our chosen CCD model. Kinetic analysis demonstrated a pseudoorder reaction model with an R2 ˃ 0.92, while the Sips isotherm describes the adsorption process. Thermodynamic studies revealed spontaneous adsorption, suggesting a physical character enhanced by a positive entropy variation.

Adsorption of ciprofloxacin from aqueous environment by using synthesized nanoceria

58%

Rahdar A. , Rahdar S. , Ahmadi S. , Fu J.

2019

tom Vol. 26, nr 2

299--311

Antibiotics are widely detected emerging contaminants in water environments and possess high potential risks to human health and aquatic life. However, conventional water treatment processes cannot remove them sufficiently. To develop innovative nanoadsorbents for effectively remove antibiotic contaminants from water environment, nanoceria were prepared via in situ precipitation method, and evaluated their adsorption capacity for a model antibiotic, ciprofloxacin (CIP). The properties of the prepared nanoceria were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD) and vibration sample magnetization (VSM). The effect of various operating parameters such as pH, initial CIP concentration, contact time, and adsorbent dosage on adsorptions of CIP were studied in batch experiments. Maximum adsorption capacity of the nanoceria was 49.38 mg/g at the conditions of pH 5, initial CIP concentration of 200 mg/dm3 and adsorbent dosage of 0.2 g/dm3, when 95.43 % of the CIP was removed. For adsorption kinetics, both pseudo-first-order and pseudo-second-order models can well describe the experimental data, indicating that the adsorption process was controlled by both physical diffusion and chemical interaction. For adsorption isotherms, the Freundlich model could fit the experimental data better than the Langmuir and Temkin models, suggesting a multilayer adsorption process. The thermal dynamics study showed the absorption process was spontaneity, exothermic, and irreversible. Finally it was concluded that the nanoceria can be used effectively for CIP removal.