Evaluation of Zero-Valent Iron for Pb(II) Contaminated Soil Remediation: From the Analysis of Experimental Mechanism Hybird with Carbon Emission Assessment

Junfang Sun,Angran Tian,Qiang Tang,Feiyang Jiang,Zheyuan Feng,Yu Zhang

doi:10.3390/su13020452

Junfang Sun, Angran Tian + Show 4 more

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https://doi.org/10.3390/su13020452

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Abstract

Carbon emission is one of the main causes of global climate change, thus it is necessary to choose a low-carbon method in the contaminated soil remediation. This paper studies the adsorption ability of ZVI on Pb(II) contaminated soils under different working conditions. The removal efficiency of Pb(II) was 98% because of the suitable ZVI dosage, log reaction time and low initial solution concentration. The whole balancing process was much fast according to the pseudo-second-order kinetic and Freundlich isothermal model. Moreover, sequential extraction procedure (SEP) showed Pb(II) was transformed from Fe/Mn oxides-bound form to residual form in Pb(II) contaminated soils. From scanning electron microscopy (SEM), Brunauer-Emmett-Teller method (BET) and X-ray diffraction (XRD) results, it was confirmed that zero-valent iron (ZVI) stabilizes Pb(II) pollutants mostly through the combination of chemical adsorption and physical adsorption. The economic and carbon emission assessments were used to compare the cost and carbon emissions of different methods. The results show that ZVI adsorption has excellent economic benefits and low carbon emission.

Highlights

Serious global climate change is the huge challenge facing the world [1].Carbon dioxide as the emission source of greenhouse gases has attracted extensive interest [2]
After each sample was stable for 16 d, the Tessier five-step sequence extraction procedureand wasthe to zero-valent iron (ZVI)
When the concentration is reduced to a certain extent, the adsorption reaction will be difficult to proceed and increasing ZVI cannot effectively reduce the equilibrium concentration

Summary

Introduction

Serious global climate change is the huge challenge facing the world [1].Carbon dioxide as the emission source of greenhouse gases has attracted extensive interest [2]. Previous studies have shown that the use of high embodied carbon building material is the main source of carbon emission in developing countries [3]. Reducing the use of high-carbon material is one of the main opportunities to reduce carbon emission and mitigate global climate change. As a typical high-carbon material, cement has in common usage in contaminated soil remediation because of its low price and excellent effect [4]. By mixing it with contaminated soil, it can reduce the migration of pollutants to surrounding environment by solidification and stabilization [5,6]. Considering its huge carbon emission, it is detrimental to the climate and needs to be replaced by a low-carbon, efficient and low-cost method

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Conclusion