Copper removal from water using a bio-rack system either unplantedor planted with Phragmites australis, Juncus articulatus and Phalarisarundinacea

Artículo de publicación ISIA bio-rack system was developed for treating Cu-contaminated freshwaters. Each pilot constructed wet-land (CW, 110 dm3) contained 15 perforated vertical pipes filled with a mixture of gravel (diorite; 80%)and perlite (20%) and assembled as a rack. The whole experimental device consisted of 12 CW plantedeither with Phragmites australis, Phalaris arundinacea or Juncus articulatus, and unplanted as control (intriplicates). All plants were sampled at a Cu-contaminated site. The CWs were filled with a mix of freshwa-ter (30%) from the Jalle d’Eysines River (Bordeaux, France) and tap water (70%). Water was spiked with Cu(2.5 M, 158.5 g L−1). Three CW batches were carried out, i.e. in early spring (March, S#1), beginning ofthe growing season (May, S#2), and peak growing season (June, S#3). The S#3 water was initially acidifiedto pH 6. For all batches, water was recirculated in the CW during 14 days. Physico-chemical parameters(pH, electrical conductivity, redox potential, BOD5and Cu2+concentrations) were measured every threedays. Water pH of both S#1 and #2 ranged between 7.8 and 8.5 for all treatments during the experi-ment. Initial and final total Cu concentrations were analysed for all CWs and batches. Relative TreatmentEfficiency Index (RTEI) indicated the plant effect compared to the unplanted CW. Free Cu2+removal was