Stabilization of Iron (Micro)Particles with Polyhydroxybutyrate for In Situ Remediation Applications

Laura Chronopoulou,Francesco Valentino,Cleofe Palocci,Ida Pettiti,Stanisław Wacławek,Miroslav Černík,Marco Petrangeli Papini

doi:10.3390/app6120417

Abstract

Groundwater is an extremely important resource that may, however, contain a variety of toxic and bioaccumulative contaminants. Traditional “Pump and Treat” technologies for treating contaminated groundwater are no longer time- or cost-effective; therefore, new technologies are needed. In this work, we synthesized core–shell materials of micrometric dimensions based on the interaction of iron particles (the core) and fermentable biopolymers such as polyhydroxybutyrate (PHB, the surrounding shell) to be used in permeable reactive barriers for the removal of chlorinated pollutants from contaminated groundwater. The materials were prepared by precipitation techniques that allowed stable preparations to be obtained, whose chemico-physical properties were thoroughly characterized by scanning electron microscopy, porosimetry, Fourier transform infrared spectroscopy (FTIR), thermogravimetric analyses, disc centrifuge analysis, and dynamic light scattering. The properties of the prepared materials are very promising, and may enhance the performance of permeable reactive barriers towards chlorinated compounds.

Highlights

In many parts of Europe—especially where surface water is of limited supply or poor quality—groundwater is a fundamental resource
We first investigated the morphology of the zero-valent iron (ZVI) sample used for the preparation of ZVI–PHB complexes by using Scanning electron microscopy (SEM) microscopy, which revealed a highly irregular and microporous morphology (Figure 1A)
This is more evident for the ZVI–PHB sample prepared with the highest quantity of PHB (ZVI/PHB ratio of 1:2 w/w), where the polymer seems to have formed a film on the Fe surface (Figure 1D)

Summary

Introduction

In many parts of Europe—especially where surface water is of limited supply or poor quality—groundwater is a fundamental resource. It is used as the main source of drinking water by many European cities and towns, and it is a major source for irrigation in most European countries. A variety of toxic and bioaccumulating contaminants have been detected in groundwater, including a wide spectrum of chlorinated hydrocarbons, halogenated aliphatic hydrocarbons, pesticides, pharmaceuticals, and metals [1]. One of the most largely applied approaches in groundwater remediation is based on the so called “Pump and Treat” (P & T) technology, in which the whole contaminated plume is intercepted by a hydraulic barrier, and the extracted water is treated on-site before being discharged, typically in

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Conclusion