Phytomanagement of a Trace Element-Contaminated Site to Produce a Natural Dye: First Screening of an Emerging Biomass Valorization Chain

Alexandre Perlein,Valérie Bert,Rodolphe Gaucher,Annelore Wens,Jeroen Geuens,Arnaud Papin,Erik Meers,Marcella Fernandes De Souza

doi:10.3390/app112210613

Abstract

The study of different possible biomass valorization routes is crucial in order to diversify phytomanagement options, allowing the landowner/stakeholder to choose the best option based on site characteristics and the benefits of local value chains. In the current study, field and laboratory experiments were conducted to assess the suitabilitity of Malva sylvestris L. for the phytoattenuation of a dredged sediment disposal site contaminated with trace elements (trace element (Cd, Cu, Pb, and Zn). The selected crop was Malva sylvestris, a flowering plant from which a colourant can be extracted to be used in dying of textiles as a way to valorize the produced biomass grown on this contaminated land. Under the conditions of the investigated site, the analysis of TE in the sediment and the biomass matrix showed no effect of M. sylvestris on the sediment TE contamination mobility with an excluder phenotype (Bioconcentration factor < 1). Metal concentrations were found to be the highest in the leaves followed by in the stem and flower. The dye extract obtained from the flower part of M. sylvestris permitted the silk alum-pretreated fabric to be dyed yellow, and the TE concentration in the dyed textile fabrics respected the threshold values set by OEKO-Tex standard 100.

Highlights

Marginal lands can be characterized as soils that are unsuitable for conventional utilization purposes due to several causes, with contamination or soil fertility problems being the most common causes [1,2]
The Cd, Cu, Pb, and Zn concentrations in the extractable solution were superior to the values that are frequently retrieved in extractable solutions that are reported in the standard ISO 19730:2008 (E) (Cd: 0.005 μg g−1; Cu: 0.25 μg g−1; Pb: 0.02 μg g−1; Zn: 0.25 μg g−1) [39]
The sediment’s total and extractable trace element (TE) concentration evidenced that Cd, Cu, Pb, and Zn were the cause of the most concern due to their potential environmental risks

Summary

Introduction

Marginal lands can be characterized as soils that are unsuitable for conventional utilization purposes due to several causes, with contamination or soil fertility problems being the most common causes [1,2]. Phytostabilization consists of the use of plant species with an excluder phenotype, i.e., a plant with a bioconcentration factor < 1, to limit the TE transfer between the soil and the aboveground part of the plant. The combination of a more gradual improvement of soil quality using plant-based techniques with the economic valorization of the produced biomass is referred to as phytoattenuation. In this strategy, the economic use of the land as well as the risk mitigation of the contamination itself are the primary goals

Objectives

Methods

Results

Conclusion