Sorption of silver ion from aqueous solutions using conducting electroactive polymers

Abstract

In this research polypyrrole (PPy) and polyaniline (PAni) conducting polymers which were synthesized chemically on the surface of wood sawdust (SD). These electroactive polymers as coated form on sawdust then were used for sorption or removal of silver ion from aqueous solutions under simple open circuit conditions. The effects of some important parameters such as pH, initial concentration, sorbent dosage, and contact time on uptake of silver ion were also investigated in this research. The experiments were carried out using both batch and column systems at room temperature. The treatments of the data were carried out using both Freundlich and Langmuir adsorption isotherms. In order to find out the possibility of the regeneration and reuse of the exhausted adsorbent, desorption studies were also performed. It was found that conducting electroactive polymers such as PPy or PAni are efficient sorbents for removal of the silver ions from aqueous solutions. Sorption/desorption processes can be simply carried out with pH control with satisfactory performance. Recovery percentage observed for PAni/SD in column study was more than PPy/SD and SD, under the same operational conditions.

Application of poly 3‐methylthiophene for removal of silver ion from aqueous solutions

“…In the case of P3MTh/SD, sorption capacity of silver ion was much higher than SD and even higher than sawdust coated by PAni and PPy as we have previously reported. 13 The proposed mechanism for removal of silver ion employing our currently introduced adsorbent may be ionic, chelation, redox reactions. Higher sorption of silver ion by P3MTh/SD can also be explained using Pearson hard-soft acidbase theory.…”

“…This might be due to the stronger interactions between sulfur atoms (in PTh) and silver ions compared to NAH groups in PPy or PAni. 13 …”

“…However, in this article we have introduced a new application of polythiophene in which is mainly based on its chemical structure and also redox activity of the polymer as we have previously reported for PPy and PAni conducting electroactive polymers. 13 However, the currently introduced adsorbent behaves more effective for uptake of silver ion from aqueous solution than PPy and PAni electroactive polymers. This might be due to the stronger interactions between sulfur atoms (in PTh) and silver ions compared to NAH groups in PPy or PAni.…”

“…[7][8][9][10] We have already shown that polypyrrole (PPy) and polyaniline (PAni)-conducting electroactive polymers can be effectively used for removal of some heavy metal ions (e.g., Hg 2þ , Pb 2þ , Ag þ ) from aqueous solutions. [11][12][13] Conducting polymers such as PPy, PAni, and polythiophene have been the focus of numerous theoretical and experimental investigations in the last 2 decades.…”

Removal of Nitrite Ions from Aqueous Solutions Using Conducting Electroactive Polymers

“…Recently, we have found that polypyrrole and polyaniline conducting electroactive polymers (CEPs) can be employed for removal of some toxic metal ions from aqueous solutions [5,6]. Synthesis of these reactive and functional polymers have been carried out by either electropolymerization at a conductive substrate (electrode) through the application of an external potential, or chemical polymerization in solution by the use of a chemical oxidant [7][8][9][10].…”