Binary adsorption of [Pb(II) + Co(II)] from aqueous solution using thiolated saw dust.

Neha Dhiman

doi:10.2166/wst.2021.454

Abstract

Technology advancement has contributed to an increase in industrial activities, resulting in the introduction of metal ions into water resources at concentrations well above the WHO limits. Heavy metals are highly toxic and carcinogenic; they usually occur as multicomponent mixtures in the aquatic environment. In the present study, batch experiments have been conducted to study the dependence of varying concentration, time, pH and temperature on the uptake of Pb(II) as a pure component under equilibrium conditions using thiolated saw dust. Saw dust has been chemically modified with thioglycolic acid and characterised using proximate and FTIR analyses, the degree of thiolation has also been determined. To determine the effect of the presence of Co(II) ions on the uptake of Pb(II) ions, batch experiments for [Pb(II) + Co(II)] mixture have been carried out for concentration ratios of 1:0, 1:1, 1:2, 1:3, 1:4 of Pb:Co at pH 5 and data has been interpreted using Langmuir competitive isotherm, which shows that adsorption of Pb(II) has been suppressed by the presence of Co(II) ions in the binary solution, hence the adsorption process is antagonistic in nature. The study also indicates the possibility of simultaneous removal of both metal ions using low cost bioadsorbent, which is economical especially for application in small-scale industries.

Highlights

In the last few decades, there has been a tremendous increase in the deterioration of the quality of freshwater due to rapid growth of human activities and the accelerated pace of industrialization (Czikkely et al 2018)
Literature studies reveal that chemical modification of bioadsorbents enhances their surface capability, which is attributed to the presence of hemicellulose, lignin or other functional groups (Mahmood et al 2017)
The present study aims to check the surface assimilation behaviour of Pb(II) ions from aqueous solution in pure form as well as in the presence of Co(II) ions from a binary mixture of [Pb(II) þ Co(II)] using thiolated saw dust (Robert & Girish 2018; Chikri et al 2020) as adsorbent

Summary

Introduction

In the last few decades, there has been a tremendous increase in the deterioration of the quality of freshwater due to rapid growth of human activities and the accelerated pace of industrialization (Czikkely et al 2018). Lead and cobalt are highly toxic and are released into natural waters from various industrial activities including mining, refining ores, batteries and metal plating (Rashid & Yaqub 2017). A large number of methods have been used for the removal of these heavy metal ions from wastewater, these are chemical precipitation, ion exchangers, chemical oxidation/reduction, reverse osmosis, electro dialysis, and ultrafiltration. Most of these methods have their limitations related to disposal problems, low efficiency, sensitive operation and production of secondary sludge (Rashid & Yaqub 2017; Czikkely et al 2018), which increases its cost for application in small-scale industries. There is no need for regeneration, which makes the sorption process of treating wastewaters cost effective and more economical for small-scale industries

Methods

Results

Conclusion