Modified Multiwalled Carbon Nanotubes for Treatment of Some Organic Dyes in Wastewater

M I Mohammed,Dhiyaa A Hussein Al-Timimi,Adnan A Abdul Razak

doi:10.1155/2014/201052

M I Mohammed, Dhiyaa A Hussein Al-Timimi + Show 1 more

Open Access

https://doi.org/10.1155/2014/201052

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Abstract

In Iraq, a large quantity of basic orange and methyl violet dyes contaminated wastewater from textile industries is discharged into Tigris River. So the aim of this work is to found an efficient and fast technique that can be applied directly for removal of such dyes from the wastewater before discharging into river. Accordingly, CNTs as a new approach prepared by CCVD technique were purified, functionalized, and used as adsorption material to remove dyes from wastewater. The effect of pH, contact time, CNTs dosage, and dyes concentration on removal of pollutants was studied. The removal percentage of both dyes was proportional to the contact time, CNTs dosage, and pH and inversely proportional to the dyes concentration. The results show that the equilibrium time was 20 and 30 min for basic orange and methyl violet dyes, respectively, and the maximum removal percentage for all dyes concentrations was at pH = 8.5 and CNTs dosage of 0.25 g/L and 0.3 g/L for methyl violet and basic orange dye, respectively. The adsorption isotherm shows that the correlation coefficient of Freundlich model was higher than Langmuir model for both dyes, indicating that the Freundlich model is more appropriate to describe the adsorption characteristics of organic pollutants.

Highlights

There are more than 100,000 types of dyes commercially available, with over 7 × 105 tons of dyestuff produced annually, which can be classified according to their structure as anionic and cationic [1]
The MWCNTs prepared, purified, and functionalized in this study are successfully used in complete removals of dyes from wastewater
Such process may be considered as a promising method for removal of pigments, dyes, and other organic species from wastewater, applying for wastewater store in a tank of textile factories which can be treated by our process before discharge into river

Summary

Introduction

There are more than 100,000 types of dyes commercially available, with over 7 × 105 tons of dyestuff produced annually, which can be classified according to their structure as anionic and cationic [1]. Colored dye wastewater arises as a direct result of the production of the dye and as a consequence of its use in the textile and other industries [2]. These dyes are very stable and can be decomposed only at temperatures higher than 200∘C. There are several techniques usually used for removal of organic dyes from wastewater. CNTs, as newly emerging carbonaceous materials, have attracted considerable interests as potential adsorbents for water treatment application due to their high specific surface area, distinct structure, and modifiable surface chemistry [6]. CNTs have been proven to possess great potential for removing many kinds of pollutants such as resorcinol [12], aniline [13], ethyl benzene [14], and phenol [15]

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