A promising and cost-effective biochar adsorbent derived from jujube pit for the removal of Pb(II) from aqueous solution

Junkai Gao,Xuebin Li,Mouyuan Yang,Jinbao Wang,Yu Liu,Yan Chen

doi:10.1038/s41598-020-64191-1

Abstract

This study evaluated the Pb(II) sorption capacity of jujube pit biochar (JPB) in aqueous solution, which was derived from jujube pit by pyrolysis and used as a promising and economical adsorbent. More importantly, the utilization of JPB could realize the recycling of agricultural residues. The JPB was characterized using conventional science technologies, including SEM, BET and FT-IR, and the sorption capacity of JPB for lead ions was investigated according to different adsorption parameters, such as the kinetics data, solution pH, isotherms data, coexisting ions of Na+ and K+, desorption and reusability, and solution temperature. The results of kinetics data suggested that the lead ion adsorption process by JPB could be fast to reach equilibrium within 30 min. Additionally, the adsorption capacity of JPB for Pb(II) was calculated to be maximum for 137.1 mg/g at pH 6.0. More importantly, after five cycles of desorption and reuse, the JPB still reached 70% of its original adsorption capacity. All the results suggested that JPB had a broad application prospect for the purification of lead ions in practical.

Highlights

Pb(II) has serious contamination with toxicity in aqueous soulution[1] that is extremely harmful to human health[2,3,4]
The wrinkled surface of jujube pit biochar (JPB) could make its surface area enlarged and make more active and adsorbable sites exposed on the outside[28], which could make a promotion for lead ions adsorbed onto the JPB surface more easily[29]
The adsorption amounts for different solution pH values are presented in Fig. 10., and the results revealed that the adsorption amount of lead ions on JPB increased with the pH increased from 2.0 to 6.0

Summary

Introduction

Pb(II) has serious contamination with toxicity in aqueous soulution[1] that is extremely harmful to human health[2,3,4]. Some physical and chemical technologies, such as electrodialysis[5], flocculation[6], ion exchange[7], chemical precipitation[8], membrane filtration[9] biosorption[10] and adsorption[11], have been applied to remove lead ions Among all these purification strategies, adsorption is a promising and attractive method because the operation process for adsorption is simple, the operation cost is low and the possibility of secondary pollution is minimal[12]. According to the experimental results, the JPB usded as a novel adsorbent for lead ion adsorption was favorable, and JPB has the potential to be a promising and cost-effective biochar adsorbent for removing lead ions in practical applications

Methods

Results

Conclusion