Antimony Immobilization in Primary-Explosives-Contaminated Soils by Fe-Al-Based Amendments.

Ningning Wang,Tianxiang Xia,Chengjun Zhang,Yucong Jiang,Zhiyuan Wu,Feng Xu,Dan Zhang

doi:10.3390/ijerph19041979

Abstract

Soils at primary explosives sites have been contaminated by high concentrations of antimony (Sb) and co-occurring heavy metals (Cu and Zn), and are largely overlooked and neglected. In this study, we investigated Sb concentrations and species and studied the effect of combined Fe- and Fe–Al-based sorbent application on the mobility of Sb and co-occurring metals. The content of Sb in soil samples varied from 26.7 to 4255.0 mg/kg. In batch experiments, FeSO4 showed ideal Sb sorption (up to 97% sorption with 10% FeSO4·7H2O), whereas the sorptions of 10% Fe0 and 10% goethite were 72% and 41%, respectively. However, Fe-based sorbents enhanced the mobility of co-occurring Cu and Zn to varying levels, especially FeSO4·7H2O. Al(OH)3 was required to prevent Cu and Zn mobilization. In this study, 5% FeSO4·7H2O and 4% Al(OH)3 mixed with soil was the optimal combination to solve this problem, with Sb, Zn, and Cu stabilizations of 94.6%, 74.2%, and 82.2%, respectively. Column tests spiked with 5% FeSO4·7H2O, and 4% Al(OH)3 showed significant Sb (85.85%), Zn (83.9%), and Cu (94.8%) retention. The pH-regulated results indicated that acid conditioning improved Sb retention under alkaline conditions. However, no significant difference was found between the acidification sets and those without pH regulation. The experimental results showed that 5% FeSO4·7H2O + 4% Al(OH)3 without pH regulation was effective for the stabilization of Sb and co-occurring metals in primary explosive soils.

Highlights

Antimony (Sb) is an element of growing environmental concern because of the widespread use and uncontrolled release of Sb compounds into the environment [1,2,3,4]
Antimony was the main contaminant in this primary explosives site and was
Antimony was the main contaminant in this primary explosives site and was 0.34–211.8 times higher than the Chinese screening value of the first land use category (20 mg/kg), based on the document of “Soil Environmental Quality

Summary

Introduction

Antimony (Sb) is an element of growing environmental concern because of the widespread use and uncontrolled release of Sb compounds into the environment [1,2,3,4]. Antimony has a carcinogenic potential [5] and Sb(III) has been shown to potentially cause lung cancer in female rats [6]. Background concentrations of Sb in soil tend to be lower than 1 mg/kg [3]. An increasing number of studies have shown that antimony pollution is a global issue [11,12] because of its toxicity to humans and its role in causing liver, skin, and respiratory and cardiovascular diseases [10].

Methods

Results

Conclusion