Adsorption Studies of Coconut Shell Carbons Prepared by KOH Activation for Removal of Lead(II) From Aqueous Solutions

Chengwen Song,Guangrui Gao,Shuaihua Wu,Ping Tao,Mihua Shao,Murong Cheng

doi:10.3390/su6010086

Abstract

Removal of Pb2+ from aqueous solutions using coconut shell carbons produced by KOH activation is performed in this paper. Morphology and pore structure characteristic of coconut shell carbons are analyzed by SEM and nitrogen adsorption techniques. Effects of adsorbent concentration, agitation time and initial ion concentration on the adsorption behavior are investigated, and adsorption isotherm and kinetics on coconut shell carbons are also studied. The results show that high weight ratio of KOH/sample is favorable to produce rich porous structure. The resultant coconut shell carbons with a high specific surface area of 1135 m2/g is obtained and demonstrates good adsorption potential on removal of Pb2+ from aqueous solutions. Adsorption data fit well with Freundlich and Halsey isotherms. The kinetic studies indicate that adsorption behavior can be described by pseudo-second-order kinetic model, which also follows external diffusion and intra-particle diffusion in the adsorption process.

Highlights

Water pollution caused by heavy metals has posed a significant threat to the environment and public health because of their toxicity, accumulation in the food chain and persistence in nature [1].Among these heavy metals, Pb2+, coming from battery manufacturing, ceramic and glass manufacturing, Sustainability 2014, 6 metal planting and finishing, printing, and production of lead additives for gasoline, is known to have a severe toxic damage to neuronal system, kidneys, reproductive system, liver and brain [2,3]
Many large pores with honeycomb shape are formed on the surface of coconut shell carbons, which shows KOH is effective in creating well-developed pores in coconut shell carbons
They both exhibit the typical type I isotherm according to the IUPAC classification, which suggests a predominantly microporous structure

Summary

Introduction

Water pollution caused by heavy metals has posed a significant threat to the environment and public health because of their toxicity, accumulation in the food chain and persistence in nature [1]. Among these heavy metals, Pb2+, coming from battery manufacturing, ceramic and glass manufacturing, Sustainability 2014, 6 metal planting and finishing, printing, and production of lead additives for gasoline, is known to have a severe toxic damage to neuronal system, kidneys, reproductive system, liver and brain [2,3]. The main objective of this research is to analyze adsorption behavior of Pb2+ on coconut shell carbons and evaluate its potential in removal of

Objectives

Results

Conclusion