Ahmad Baraka

Adsorptive removal of tartrazine and methylene blue from wastewater using melamine-formaldehyde-tartaric acid resin (and a discussion about pseudo second order model)

Abstract In this study, a new resin Melamine-Formaldehyde-Tartaric acid (MF-T) was synthesized to investigate the removal of tartrazine (TZ) and methylene blue (MB) dyes. The resin was chemically, physically and morphologically characterized using IR, BET, SEM, TGA, and water content analyses. Kinetics and isotherms of TZ and MB adsorption by MF-T were studied applying batch method. Adsorption-rate data was modeled by pseudo first order (PFO) and pseudo second order (PSO) kinetic models. It was concluded that the rate of adsorption follows PSO model for both dyes. Isotherm study suggests Freundlich and Langmuir models to represent adsorption of TZ and MB respectively at equilibrium. Thermodynamic study revealed that adsorption of TZ and MB onto MF-T is spontaneous. Adsorption is exothermic for TZ in the range 15–30°C and endothermic in the range 30–45°C while it is exothermic for MB over the whole temperature studied range; 15–45°C. The regeneration experiment of MF-T by a physical treatment indicated the...

Degradation of methylene blue adsorbed onto transparent adsorbent by UV-illumination (simple regeneration method)

Abstract This work presents in-pores degradation of a dye that was subjected to adsorption into a transparent adsorbent. The degradation was performed by UV-illumination of the dye-loaded adsorbent. This degradation by UV-illumination is considered as a regeneration technique for the adsorbent. For this specific aim, a new transparent adsorbent was prepared. It is a hybrid resin-gel composed of melamine formaldehyde tartaric acid/acrylamide tartaric acid (MFT/AT). methylene blue (MB) was selected as a typical contaminant dye due to its known degradability by UV rays. A sample of MFT/AT was used through 10-cycles of MB-adsorption/UV-illumination applying batch method. For each cycle, MB was apparently completely degraded. Rate of MB-adsorption by MFT/AT was investigated applying pseudo second order model for the 1st and 10th cycles. It was found that adsorption rate and capacity were not significantly changed (rate constants = 0.186, 0.199 g mg−1 min−1 and capacities = 0.264, 0.258 mg g−1 respectively). A ...

A novel kinetic model for batch aqueous-solution/porous-solid adsorption systems

In this work, a novel kinetic model is introduced to represent the batch adsorption for aqueous-solution/porous-solid systems. The model proposes that the rate of adsorption is controlled by three parameters: solute concentration, n-powered time, and what is called varying-resistance against adsorption. Applicability of the model was examined by investigating the performance of the model considering the batch adsorption of methylene blue from aqueous solution onto three different adsorbents: hybrid resin-gel (MFTAT), commercial exhausted black tea, and dried pea husk. The effect of initial concentration was studied to explore model behavior. According to results and determined data, the DB-model successfully estimated the adsorption capacities and the rate constants. In addition, the DB-model managed to recognize the relative contributions of diffusion in the adsorption processes.

Gamma Radiation Effect on the Electrical Properties of PANI Film

The electrical properties of nonconductive polyaniline (PANI) films exposed to gamma radiation for the purpose of gamma dosimeter were presented in this work. By exposing films to doses of gamma radiation up to 10 kGy, the films showed visually apparent gradual change in the current- voltage (I-V) characteristics. Electrical, conductivity also increased regularly in the same dose range. It can be suggested that gamma radiation dose has an effect on transformation of polyaniline in its nonconductive form to polyaniline in its conductive form (PANI-HCl) which may be used for dosimeter in a gamma doses up to 10 KGy.

Metal oxide films/structures for gamma radiation detection

In this work, aluminum oxide, nickel oxide films were prepared for the purpose of gamma radiation dosimetry using several deposition techniques. A significant change in the (I-V) measurements for the as deposited films, p-n junction film structures have been observed upon exposure to high and low gamma radiation doses which proofs the promising characteristics of these oxide films for gamma radiation dosimetry applications.