Copper removal from water using a bio-rack system either unplanted or planted with Phragmites australis, Juncus articulatus and Phalaris arundinacea

• Published in: Ecological engineering 2014-03, Vol.64, p.291-300
• Main Authors: Marchand, Lilian, Nsanganwimana, Florien, Oustrière, Nadège, Grebenshchykova, Zhanna, Lizama-Allende, Katherine, Mench, Michel
• Format: Article
• Language: English
• Subjects: Animal, plant and microbial ecology; Applied ecology; Biodegradation of pollutants; Biofilm; Biological and medical sciences; Biotechnology; Conservation, protection and management of environment and wildlife; Constructed wetland; Decontamination; Environment and pollution; Environmental degradation: ecosystems survey and restoration; Fundamental and applied biological sciences. Psychology; Industrial applications and implications. Economical aspects; Life Sciences; Macrophyte; Phytoremediation
• ISSN: 0925-8574; 1872-6992
• DOI: 10.1016/j.ecoleng.2013.12.017

•Total Cu removal in pilot constructed wetlands (CW) using bioracks planted with three macrophytes ranged between 7% and 90%.•Compared to early spring (March), Cu removal by bio-racks was higher during the growing season (May).•The use of the RTEI index completed the information given on the Cu removal rates by the removal percentage calculation.•Compared to the unplanted CW, the three macrophytes weakly influenced the Cu removal rate, and even J. articulatus, decreased it. A bio-rack system was developed for treating Cu-contaminated freshwaters. Each pilot constructed wetland (CW, 110dm3) 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 planted either with Phragmites australis, Phalaris arundinacea or Juncus articulatus, and unplanted as control (in triplicates). All plants were sampled at a Cu-contaminated site. The CWs were filled with a mix of freshwater (30%) from the Jalle d’Eysines River (Bordeaux, France) and tap water (70%). Water was spiked with Cu (2.5μM, 158.5μgL−1). Three CW batches were carried out, i.e. in early spring (March, S#1), beginning of the growing season (May, S#2), and peak growing season (June, S#3). The S#3 water was initially acidified to pH 6. For all batches, water was recirculated in the CW during 14 days. Physico-chemical parameters (pH, electrical conductivity, redox potential, BOD5 and Cu2+ concentrations) were measured every three days. Water pH of both S#1 and #2 ranged between 7.8 and 8.5 for all treatments during the experiment. Initial and final total Cu concentrations were analysed for all CWs and batches. Relative Treatment Efficiency Index (RTEI) indicated the plant effect compared to the unplanted CW. Free Cu2+ removal was