Arundo donax L. Biomass Production in a Polluted Area: Effects of Two Harvest Timings on Heavy Metals Uptake

Abstract

Within the framework of energy biomass production, Arundo donax L. is very promising for its capability to grow on marginal lands with high yields. This potential can be realized in unused polluted areas where the energy production can be coupled with phytoremediation, and harvested biomass represents a resource and a means to remove contaminants from the soil. Two main processes are considered to evaluate A. donax L. biomass as an energy crop, determined by the timing of harvest: anaerobic digestion with fresh biomass before winter and combustion (e.g., pyrolysis and gasification) of dry canes in late winter. The aim of this work was to evaluate the use of A. donax L. in an area polluted by heavy metals for phytoextraction and energy production at two different harvest times (October and February). For that purpose, we established in polluted area in northern Italy (Caffaro area, Brescia) an experimental field of A. donax, and included switchgrass (Panicum virgatum L.) and mixed meadow species as controls. The results obtained by ICP-MS analysis performed on harvested biomasses highlighted a differential uptake of heavy metals depending on harvest time. In particular, considering the yield in the third year, A. donax was able to remove from the soil 3.87 kg ha−1 of Zn, 2.09 kg ha−1 of Cu and 0.007 kg ha−1 of Cd when harvested in October. Production of A. donax L. for anaerobic digestion or combustion in polluted areas represents a potential solution for both energy production and phytoextraction of heavy metals, in particular Cu, Zn and Cd.

Coupling Plant Biomass Derived from Phytoremediation of Potential Toxic-Metal-Polluted Soils to Bioenergy Production and High-Value by-Products—A Review

“…Some other studies have focused on unused polluted soils where plants such as Arundo donax L. grow and can be coupled to bioenergy production. A. donax has shown high potential to be used in phytoremediation processes, and its harvested biomass represents a resource [150]. The authors proposed using the phytoremediation biomass in two different processes, depending on the time of harvesting: anaerobic digestion with fresh biomass before winter and combustion of dry canes in late winter.…”

The Potential Application of Giant Reed (Arundo donax) in Ecological Remediation

“…Pb, Cd, Mo, As, Zn, Cu, Ni, Co, Fe, Mn, Cr, Hg, Al etc. from the environment (Miao et al, 2012;Delplace et al, 2020;Danelli et al, 2021). It is a promising candidate for the phytoremediation of Zn-/Cr-contaminated soil (Li et al, 2014).…”

Weed Management Practices to Improve Establishment of Selected Lignocellulosic Crops

“…If directly planted, the rhizomes are placed at 10-20 cm soil depth [67]. Pre-grown plantlets are also widely used [63,64,68,69]. This crop is adaptable to various soil types and highly productive in marginal areas and polluted lands [68].…”

“…Pre-grown plantlets are also widely used [63,64,68,69]. This crop is adaptable to various soil types and highly productive in marginal areas and polluted lands [68]. For optimal growth, giant reed most benefits from well-drained soils with sufficient humidity [66].…”

“…In particular, weeding in May resulted in 15, 25, and 34% higher values of plant height, number of shoots per plant, and dry weight per plant, respectively, compared to letting weeds compete with giant reed until June [28]. Danelli et al [68] used mowing for weed control between the rows. Pre-emergence applications of S-Metolachlor and flumioxazin at 1390 and 71.5 g ai ha −1 , respectively, are safe according to Smith et al [48].…”