Removal of Toxic Copper Ion from Aqueous Media by Adsorption on Fly Ash-Derived Zeolites: Kinetic and Equilibrium Studies.

Gabriela Buema,Maria Harja,Luisa-Maria Trifas

doi:10.3390/polym13203468

Abstract

This study investigated the adsorption capacity of one material based on the treatment of fly ash with sodium hydroxide as a novel adsorbent for toxic Cu2+ ion removal from aqueous media. The adsorbent was obtained through direct activation of fly ash with 2M NaOH at 90 °C and 6 h of contact time. The adsorbent was characterized by recognized techniques for solid samples. The influence of adsorption parameters such as adsorbent dose, copper initial concentration and contact time was analyzed in order to establish the best adsorption conditions. The results revealed that the Langmuir model fitted with the copper adsorption data. The maximum copper adsorption capacity was 53.5 mg/g. The adsorption process followed the pseudo-second-order kinetic model. The results indicated that the mechanism of adsorption was chemisorption. The results also showed the copper ion removal efficiencies of the synthesized adsorbents. The proposed procedure is an innovative and economical method, which can be used for toxicity reduction by capitalizing on abundant solid waste and treatment wastewater.

Highlights

Copper ion is considered a toxic substance [1], whose health effects include stomachache, lung cancer and neurotoxicity
The data obtained in this study demonstrate that the low-cost and easy synthesis of this new material based on the treatment of raw fly ash with sodium hydroxide in combination with its properties represents a promising adsorbent for copper ion removal
The results obtained indicate a higher surface area when fly ash is treated with NaOH that demonstrate a good adsorption capacity for Cu2+ ion removal

Summary

Introduction

Copper ion is considered a toxic substance [1], whose health effects include stomachache, lung cancer and neurotoxicity. Several adsorbents have been tested in order to remove copper ion, such as activated carbon [8,9,10], clays [11], apatite [12], composite carbon-silica [13], magnetic materials [14,15,16], silica gel [17], hydroxyapatite [18], zeolites [19] and fly ash [5,20]. Fly ash has been investigated by many researchers as an adsorbent for heavy metal removal [21,22]. The chemical composition of fly ash produced from different types of coal has been listed in the literature [22,23]. The major phases consist of mullite, quartz and hematite [26]

Methods

Results

Conclusion