This study presents an efficient and facile method for biosynthesis of silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs) using aqueous extract of burdock root (BR), A. lappa, and their applications. The nanoparticles were characterized by ultraviolet-visible spectrophotometry, X-ray diffraction, transmission electron microscopy, energy dispersive X-ray, thermogravimetry, and differential thermal analysis. AgNPs capped the BR extract (BR-AgNPs) possessed roughly spherical geometry with an average diameter of 21.3 nm while uneven geometry of AuNPs capped the BR extract (BR-AuNPs) showed multi shapes in average size of 24.7 nm. The BR-AgNPs strongly inhibited five tested microorganism strains. In particular, the nanoparticles showed excellent catalytic activity for the conversion of pollutants within wastewater. Pseudo-first-order rate constants for the degradation of 4-nitrophenol, methyl orange, and rhodamine B were respectively found 6.77 × 10⁻³, 3.70 × 10⁻³, and 6.07 × 10⁻³ s⁻¹ for BR-AgNPs and 6.87 × 10⁻³, 6.07 × 10⁻³, and 7.07 × 10⁻³ s⁻¹ for BR-AuNPs. Graphical abstract ᅟ

Plants have immense potential for their use in the minimization of emerging environmental pollution issues. Under simulated laboratory conditions, this work investigated the growth and biochemical responses of 14-day-old cotton burdock (Arctium tomentosum Mill.) seedlings to the body burdens of multi-metals including Pb, Cu, Ni, and Zn (1.0 μM–10 mM). Biochemical traits (superoxide generation, lipid peroxidation, content of total peroxides), growth traits (axial organs growth, dry weight accumulation, leaf area), and also metal body burdens varied with types and concentrations of metals. Results indicated a significant tolerance of A. tomentosum to multi-metals that can be implicated for its potential role in the metal phytoremediation programs.

Choosing native vascular plants as nutrient and toxic element accumulators for passive biomonitoring of urban river quality is not an easy task in Mediterranean rivers, due to the particular climate determining high variations in river hydrology. To identify potential biomonitors for this area, the roots of seven species (Angelica sylvestris, Apium nodiflorum, Tradescantia fluminensis, Nasturtium officinale, Persicaria lapathifolia, Arctium lappa, Typha latifolia), growing in seven sites along the River Irno (Southern Italy), were collected in July 2010 and analyzed regarding their capability to accumulate Cd, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, V, and Zn through atomic absorption spectrometry. Notwithstanding the expected different accumulation degree among the species, they highlighted similar spatial contamination gradients, and all of them appeared suitable, alone or in combination, for river passive biomonitoring. A. nodiflorum, in particular, appeared the best biomonitor for the River Irno, where severe anthropogenic impacts were detected: high Cu and Cd contamination from vine cultivation in the upper stretch, and Pb, Zn, and Mn contamination in the medium stretch from airborne dusts coming from a cast iron foundry.