Efficient Adsorption of Lead (II) from Aqueous Phase Solutions Using Polypyrrole-Based Activated Carbon

Abdulaziz Ali Alghamdi,Fahad A Alharthi,Waseem Sharaf Saeed,Taieb Aouak,Abdel-Basit Al-Odayni,Abdullah Al-Kahtani

doi:10.3390/ma12122020

Abstract

In this study, polypyrrole-based activated carbon was prepared by the carbonization of polypyrrole at 650 °C for 2 h in the presence of four-times the mass of KOH as a chemical activator. The structural and morphological properties of the product (polypyrrole-based activated carbon (PPyAC4)), analyzed by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and thermogravimetric analysis, support its applicability as an adsorbent. The adsorption characteristics of PPyAC4 were examined through the adsorption of lead ions from aqueous solutions. The influence of various factors, including initial ion concentration, pH, contact time, and adsorbent dose, on the adsorption of Pb2+ was investigated to identify the optimum adsorption conditions. The experimental data fit well to the pseudo-second-order kinetic model (R2 = 0.9997) and the Freundlich isotherm equation (R2 = 0.9950), suggesting a chemisorption pathway. The adsorption capacity was found to increase with increases in time and initial concentration, while it decreased with an increase in adsorbent dose. Additionally, the highest adsorption was attained at pH 5.5. The calculated maximum capacity, qm, determined from the Langmuir model was 50 mg/g.

Highlights

Water pollution is a global issue, with heavy metal pollution representing one of the most serious problems
The maximum contaminant level of lead in drinking water allowed by the Environmental Protection Agency (EPA) and the World Health Organization (WHO) is 15 and 50 μg/L, respectively [7]
The objective of this study is to investigate the adsorption performance of the as-prepared polypyrrole-based activated carbon (PPyAC4) using the lead ion as a model adsorbate

Summary

Introduction

Water pollution is a global issue, with heavy metal pollution representing one of the most serious problems. Heavy metals, including lead, copper, mercury, chromium, and nickel, commonly enter aquatic systems through effluent discharge from various manufacturing processes, resulting in damages to ecosystems and human health [3,4]. They are non-biodegradable and tend to accumulate in living tissues, in human bodies, causing various diseases and significant physiological disorders such as central nervous system damage [2,5]. Among all heavy metal pollutants, lead is the most common and one of the most toxic, reaching water sources from various industrial activities such as mining, oil refining, metal plating and finishing, and battery manufacturing [4,6]. Lead poisoning can cause kidney damage, anemia, and toxicity symptoms including impaired kidney function, hypertension, and headache [8]

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Conclusion