Showing papers by "Tawfik A. Saleh published in 2012"

Chemical treatment technologies for waste-water recycling—an overview

Abstract: The global population is increasing and because of this, the world may experience great fresh water scarcity. Our water resources are limited and, hence, water treatment and recycling methods are the only alternatives for getting fresh water in the coming decades. Therefore, there is a great need for the development of a suitable, inexpensive and rapid wastewater treatment techniques and reuse or conservation methods in the present century. The different types of water treatment and recycling techniques have been discussed in terms of their basic principles, applications, costs, maintenance and suitability. Additionally, a systematic approach to water treatment and recycling involving their understanding, evaluation and selection parameters has been presented. A brief guideline for the selection of the appropriate technologies for specific applications has been evaluated. This review adds to the global discussions on water scarcity solutions.

Photo-catalyzed degradation of hazardous dye methyl orange by use of a composite catalyst consisting of multi-walled carbon nanotubes and titanium dioxide.

Abstract: The high rate of electron/hole pair recombination reduces the quantum yield of the processes with TiO2 and represents its major drawback. Adding a co-adsorbent increases the photocatalytic efficiency of TiO2. In order to hybridize the photocatalytic activity of TiO2 with the adsorptivity of carbon nanotube, a composite of multi-walled carbon nanotubes and titanium dioxide (MWCNT/TiO2) has been synthesized. The composite was characterized by means of X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), Fourier transform infrared absorption spectroscopy (FTIR), and diffuse reflectance UV–vis spectroscopy. The catalytic activity of this composite material was investigated by application of the composite for the degradation of methyl orange. It was observed that the composite exhibits enhanced photocatalytic activity compared with TiO2. The enhancement in photocatalytic performance of the MWCNT/TiO2 composite is explained in terms of recombination of photogenerated electron–hole pairs. In addition, MWCNT acts as a dispersing agent preventing TiO2 from agglomerating activity during the catalytic process, providing a high catalytically active surface area. This work adds to the global discussion of how CNTs can enhance the efficiency of catalysts.

Column with CNT/magnesium oxide composite for lead(II) removal from water.

Abstract: In this study, manganese dioxide-coated multiwall carbon nanotube (MnO2/CNT) nanocomposite has been successfully synthesized. The as-produced nanocomposite was characterized by different characteristic tools, such as X-ray diffraction, SEM, and FTIR. The MnO2/CNT nanocomposite was utilized as a fixed bed in a column system for removal of lead(II) from water. The experimental conditions were investigated and optimized. The pH range between 3 and 7 was studied; the optimum removal was found when the pH was equal to 6 and 7. The thickness of MnO2/CNT nanocomposite compact layer was also changed to find the optimum parameter for higher removal. It was observed that the slower the flow rates of the feed solution the higher the removal because of larger contact time.

Chemical Treatment Technologies for Waste‐Water Recycling — An Overview

Abstract: The global population is increasing and because of this, the world may experience great fresh water scarcity. Our water resources are limited and, hence, water treatment and recycling methods are the only alternatives for getting fresh water in the coming decades. Therefore, there is a great need for the development of a suitable, inexpensive and rapid wastewater treatment techniques and reuse or conservation methods in the present century. The different types of water treatment and recycling techniques have been discussed in terms of their basic principles, applications, costs, maintenance and suitability. Additionally, a systematic approach to water treatment and recycling involving their understanding, evaluation and selection parameters has been presented. A brief guideline for the selection of the appropriate technologies for specific applications has been evaluated. This review adds to the global discussions on water scarcity solutions.

Portable system of programmable syringe pump with potentiometer for determination of promethazine in pharmaceutical applications

Abstract: A simple and fast-automated method was developed and validated for the assay of promethazine hydrochloride in pharmaceutical formulations, based on the oxidation of promethazine by cerium in an acidic medium. A portable system, consisting of a programmable syringe pump connected to a potentiometer, was constructed. The developed change in potential during promethazine oxidation was monitored. The related optimum working conditions, such as supporting electrolyte concentration, cerium(IV) concentration and flow rate were optimized. The proposed method was successfully applied to pharmaceutical samples as well as synthetic ones. The obtained results were realized by the official British pharmacopoeia (BP) method and comparable results were obtained. The obtained t-value indicates no significant differences between the results of the proposed and BP methods, with the advantages of the proposed method being simple, sensitive and cost effective.