Developing eco-innovative chemical processes to valorise phytoremediation-borne biomasses : the PHYTOCHEM initiative

Industrial and urban activities impact our environment, especially in terms of soil pollution. During the last two decades, gentle soil remediation techniques have emerged using various plant species and the combination of microbial biotechnologies. Several phytotechnologies can be applied to produce useable biomass, alleviate pollutant linkages and restore services of polluted soils: (1) phytostabilisation, which uses perennials able to sorb and immobilize trace elements (TE) in excess in the root zone, avoiding their transfer toward groundwater and aerial parts and preventing their bioaccumulation in the food chain as well as dispersion by natural agents (2) phytoextraction, based on root-to-shoot transfer and storage of TE in harvestable plant parts. The PHYTOCHEM project aims at promoting chemically-based valorisation processes of the plant biomasses collected from polluted sites managed by eco-innovative phytotechnologies. As a first step towards the development of chemically-based valorisation processes of plant biomasses collected from polluted sites, we have successfully implemented 16 and 18 woody species at two phytomanagement sites in 2014 (Figure 1). Based on ICP-AES analysis, TE concentrations in aboveground tissues highly varied, illustrating the metal tolerance processes developed by plants, either by exclusion or accumulation. We further applied chemical processes to contaminated biomasses. For instance, optimization of an organosolv pre-treatment allowed for removing ca. 50% of Fe and Mn from contaminated biomasses, while Ecocatalysis was also successfully applied to i.e. Zn hyperaccumulating species (A. halleri)

Root biomass production in populations of six rooted macrophytes in response to Cu exposure: Intra-specific variability versus constitutive-like tolerance

Intra-specific variability of root biomass production (RP) of six rooted macrophytes, i.e. Juncus effusus, Phragmites australis, Schoenoplectus lacustris, Typha latifolia, Phalaris arundinacea, and Iris pseudacorus grown from clones, in response to Cu exposure was investigated. Root biomass production varied widely for all these macrophytes in control conditions (0.08 μM) according to the sampling site. Root biomass production of T. latifolia and I. pseudacorus in the 2.5–25 μM Cu range depended on the sampling location but not on the Cu dose in the growth medium. For P. australis, J. effusus, S. lacustris, and P. arundinacea, an intra-specific variability of RP depending on both the sampling location and the Cu-dose was evidenced. This intra-specific variability of RP depending on the sampling location and of Cu-tolerance for these last four species suggests that Cu constitutive tolerance for all rooted macrophytes is not a species-wide trait but it exhibits variability for some species

Intensify production, transform biomass to energy and novel goods and protect soils in Europe-A vision how to mobilize marginal lands

The rapid increase of the world population constantly demands more food production from agricultural soils. This causes conflicts, since at the same time strong interest arises on novel bio-based products from agriculture, and new perspectives for rural landscapes with their valuable ecosystem services. Agriculture is in transition to fulfill these demands. In many countries, conventional farming, influenced by post-war food requirements, has largely been transformed into integrated and sustainable farming. However, since it is estimated that agricultural production systems will have to produce food for a global population that might amount to 9.1 billion by 2050 and over 10 billion by the end of the century, we will require an even smarter use of the available land, including fallow and derelict sites. One of the biggest challenges is to reverse non-sustainable management and land degradation. Innovative technologies and principles have to be applied to characterize marginal lands, explore options for remediation and re-establish productivity. With view to the heterogeneity of agricultural lands, it is more than logical to apply specific crop management and production practices according to soil conditions. Cross-fertilizing with conservation agriculture, such a novel approach will provide (1) increased resource use efficiency by producing more with less (ensuring food security), (2) improved product quality, (3) ameliorated nutritional status in food and feed products, (4) increased sustainability, (5) product traceability and (6) minimized negative environmental impacts notably on biodiversity and ecological functions. A sustainable strategy for future agriculture should concentrate on production of food and fodder, before utilizing bulk fractions for emerging bio-based products and convert residual stage products to compost, biochar and bioenergy. The present position paper discusses recent developments to indicate how to unlock the potentials of marginal land