Ethylenediamine-N,N'-Disuccinic Acid (EDDS)-Enhanced Flushing Optimization for Contaminated Agricultural Soil Remediation and Assessment of Prospective Cu and Zn Transport.

Marco Race,Danilo Spasiano,Antonio Panico,Alberto Ferraro,Massimiliano Fabbricino,Alice Tognacchini,Agostino La Marca,Francesco Pirozzi

doi:10.3390/ijerph15030543

Abstract

This paper presents the results of an experimental study aimed at investigating the effect of operative parameters on the efficiency of a soil flushing process, conducted on real contaminated soil containing high amounts of Cu and Zn. Soil flushing tests were carried out with Ethylenediamine-N,N′-disuccinic acid (EDDS) as a flushing agent due to its high biodegradability and environmentally friendly characteristics. Process parameters such as Empty-Bed Contact Time (EBCT) and EDDS solution molarity were varied from 21–33 h and from 0.36–3.6 mM, respectively. Effects on the mobility of cations such as Fe and Mn were also investigated. Results showed that very high performances can be obtained at [EDDS] = 3.6 mM and EBCT = 33 h. In these conditions, in fact, the amount of removed Cu was 53%, and the amount of removed Zn was 46%. Metal distribution at different depths from the top surface revealed that Cu has higher mobility than Zn. The process results were strongly dependent on the exchange of metals due to the different stability constants of the EDDS complexes. Finally, results from a comparative study showed that soil washing treatment reached the same removal efficiency of the flushing process in a shorter time but required a larger amount of the EDDS solution.

Highlights

IntroductionIllegal disposal of industrial waste containing different pollutants, both organic and inorganic, is responsible for severe agricultural soil pollution [1]
Illegal disposal of industrial waste containing different pollutants, both organic and inorganic, is responsible for severe agricultural soil pollution [1]. Such contamination can be related to the presence of so-called emerging pollutants, such as liquid-ionic pollutants or pesticides [2], in most cases it is related to the presence of potentially toxic elements (PTEs) [3,4]
Mn removed was negligible compared to their initial concentration in the soil

Summary

Introduction

Illegal disposal of industrial waste containing different pollutants, both organic and inorganic, is responsible for severe agricultural soil pollution [1]. Such contamination can be related to the presence of so-called emerging pollutants, such as liquid-ionic pollutants or pesticides [2], in most cases it is related to the presence of potentially toxic elements (PTEs) [3,4]. The presence of Cu and Zn is quite common, because these metals have a wide application in numerous industrial processes as well as in the production of many pesticides and herbicides [5]. Public Health 2018, 15, 543; doi:10.3390/ijerph15030543 www.mdpi.com/journal/ijerph

Methods

Results

Conclusion