title: Portulaca grandiflora as green roof vegetation: Plant growth and phytoremediation experiments.
abstract: Finding appropriate rooftop vegetation may improve the quality of runoff from green roofs. Portulaca grandiflora was examined as possible vegetation for green roofs. Green roof substrate was found to have low bulk density (360.7 kg/m3) and high water-holding capacity (49.4%), air-filled porosity (21.1%), and hydraulic conductivity (5270 mm/hour). The optimal substrate also supported the growth of P. grandiflora with biomass multiplication of 450.3% and relative growth rate of 0.038. Phytoextraction potential of P. grandiflora was evaluated using metal-spiked green roof substrate as a function of time and spiked substrate metal concentration. It was identified that P. grandiflora accumulated all metals (Al, Cd, Cr, Cu, Fe, Ni, Pb, and Zn) from metal-spiked green roof substrate. At the end of 40 days, P. grandiflora accumulated 811 ± 26.7, 87.2 ± 3.59, 416 ± 15.8, 459 ± 15.6, 746 ± 20.9, 357 ± 18.5, 565 ± 6.8, and 596 ± 24.4 mg/kg of Al, Cd, Cr, Cu, Fe, Ni, Pb and Zn, respectively. Results also indicated that spiked substrate metal concentration strongly influenced metal accumulation property of P. grandiflora with metal uptake increased and accumulation factor decreased with increase in substrate metal concentration. P. grandiflora also showed potential to translocate all the examined metals with translocation factor greater than 1 for Al, Cu, Fe, and Zn, indicating hyperaccumulation property.
authors.affiliation: a Department of Chemical Engineering , Indian Institute of Technology Madras , Chennai , Tamil Nadu , India.
authors.forename: K
authors.initials: K
authors.lastname: Vijayaraghavan
authors.affiliation: b Division of Fisheries Biotechnology and Molecular Biology, Department of Biotechnology , Faculty of Science and Humanities, SRM University , Kattankulathur, Chennai , Tamil Nadu , India.
authors.forename: Jesu
authors.initials: J
authors.lastname: Arockiaraj
authors.affiliation: c Division of Biotechnology, Advanced Institute of Environment and Bioscience, College of Environmental and Bioresource Sciences , Chonbuk National University , Iksan , South Korea.
authors.forename: Seralathan
authors.initials: S
authors.lastname: Kamala-Kannan
mesh_terms: D000535:Aluminum / Q000378:metabolism*; D001673:Biodegradation, Environmental; D007194:India; D019216:Metals, Heavy / Q000378:metabolism*; D031822:Portulaca / Q000254:growth & development / Q000378:metabolism*; D011891:Rain / Q000737:chemistry; D012989:Soil Pollutants / Q000378:metabolism*
chemical_list: D019216:Metals, Heavy; D012989:Soil Pollutants; D000535:Aluminum
keywords: bioconcentration; biosorption; green roof; phytoextraction; succulent