Polyaniline/Nanomaterial Composites for the Removal of Heavy Metals by Adsorption: A Review

Abstract

Heavy metals represent one of the most important kinds of pollutants, causing serious threats to the ecological balance. Thus, their removal from aqueous solution is a major environmental concern worldwide. The process of adsorption—being very simple, economical, and effective—is widely applied for the decontamination of wastewaters from heavy metals. In this process, the adsorbent is the key factor affecting the performance; for this reason, significant efforts have been made to develop highly efficient and selective adsorbents with outstanding properties. This paper presents a detailed overview of the research on different methods of synthesis of nanocomposite materials based on the polymer polyaniline combined with nanomaterials, along with the influence of the synthesis method on their size, morphology, and properties. In addition, the study evaluates the adsorption efficiency of various developed nanocomposites for the adsorption of heavy metals from aqueous solution. From an economical and environmental point of view, the regeneration studies of the nanocomposites are also reported.

Cr(VI) removal from the aqueous solutions by the samples of polyanyline doped with phosphoric acid

“…Агентство США з охорони навколишнього середовища (USEPA) оголосило процес сорбції одним із чудових та найкращих методів очищення стічних вод серед інших [34]. За допомогою адсорбційних методів можна практично повністю видаляти з вод важкі метали, серед яких і хром [35,36]. Особливістю адсорбційних методів є можливість регенерування адсорбентів і, відповідно, їхнє багаторазове використання.…”

Facile Synthesis of the Polyaniline@Waste Cellulosic Nanocomposite for the Efficient Decontamination of Copper(II) and Phenol from Wastewater

“…Among conductive polymers, polyaniline has gained huge research attention because of its important characteristics, including a simple synthesis route, environmental stability, good electrical conductivity, etc. Various applications related to active functional groups, such as amine, imine, and secondary amino groups on the polyaniline structure, make it suitable for removing dyes, toxic metals, and organic chemicals and dyes from the aqueous phase [ 26 ]. However, PANI’s significance is constrained by several drawbacks, including insolubility or low/partial solubility in common solvents, long-chain polymer aggregates, poor processability, and infusibility.…”

“…The most attractive PANI/cellulose-based nanocomposites exhibit electrical conductivity because of the combined use of cellulose nanofillers and PANI matrix. Such nanomaterials, which have enhanced conductive, electrical, mechanical, and adsorbing capabilities, are widely used in the water treatment and electronics industries, as well as in the biomedical and electronics industries [ 24 , 26 ]. Both chemical and electrochemical oxidative polymerization in acidic media can be used to synthesize PANI.…”

Polyaniline Modified CNTs and Graphene Nanocomposite for Removal of Lead and Zinc Metal Ions: Kinetics, Thermodynamics and Desorption Studies

“…In general, it was observed that PANI/GO composites absorb heavy metals efficiently, but most publications focus on the most common Zn (II), Cd (II), Pb (II) and Cu (II) ions. Hajjaoui et al [ 19 ] reported good removal capacities of heavy metal ions by modifying multilayer CNTs with polyaniline. However, the use of PANI is limited by its extremely low solubility in water and most known solvents, as well as poor mechanical properties—the polymer powder does not adhere to other materials.…”