title: Integrated Cr(VI) removal using constructed wetlands and composting.
abstract: The present work was conducted to study integrated chromium removal from aqueous solutions in horizontal subsurface (HSF) constructed wetlands. Two pilot-scale HSF constructed wetlands (CWs) units were built and operated. One unit was planted with common reeds (Phragmites australis) and one was kept unplanted. Influent concentrations of Cr(VI) ranged from 0.5 to 10mg/L. The effect of temperature and hydraulic residence time (8-0.5 days) on Cr(VI) removal were studied. Temperature was proved to affect Cr(VI) removal in both units. In the planted unit maximum Cr(VI) removal efficiencies of 100% were recorded at HRT's of 1 day with Cr(VI) concentrations of 5, 2.5 and 1mg/L, while a significantly lower removal rate was recorded in the unplanted unit. Harvested reed biomass from the CWs was co-composted with olive mill wastes. The final product had excellent physicochemical characteristics (C/N: 14.1-14.7, germination index (GI): 145-157%, Cr: 8-10mg/kg dry mass), fulfills EU requirements and can be used as a fertilizer in organic farming.
authors.affiliation: Department of Environmental and Natural Resources Management, University of Patras, G. Seferi 2, GR-30100 Agrinio, Greece.
authors.forename: Mar-Yam
authors.initials: MY
authors.lastname: Sultana
authors.affiliation: Department of Environmental and Natural Resources Management, University of Patras, G. Seferi 2, GR-30100 Agrinio, Greece.
authors.forename: Abu Khayer Md Muktadirul Bari
authors.initials: AKMMB
authors.lastname: Chowdhury
authors.affiliation: Department of Environmental and Natural Resources Management, University of Patras, G. Seferi 2, GR-30100 Agrinio, Greece.
authors.forename: Michail K
authors.initials: MK
authors.lastname: Michailides
authors.affiliation: Department of Environmental and Natural Resources Management, University of Patras, G. Seferi 2, GR-30100 Agrinio, Greece. Electronic address: cakratos@upatras.gr.
authors.forename: Christos S
authors.initials: CS
authors.lastname: Akratos
authors.affiliation: Department of Environmental and Natural Resources Management, University of Patras, G. Seferi 2, GR-30100 Agrinio, Greece.
authors.forename: Athanasia G
authors.initials: AG
authors.lastname: Tekerlekopoulou
authors.affiliation: Department of Environmental and Natural Resources Management, University of Patras, G. Seferi 2, GR-30100 Agrinio, Greece; Institute of Chemical Engineering Sciences, Stadiou Str., Platani, GR-26504 Patras, Greece.
authors.forename: Dimitrios V
authors.initials: DV
authors.lastname: Vayenas
mesh_terms: D002857:Chromium / Q000378:metabolism; D005525:Food-Processing Industry; D007220:Industrial Waste; D031658:Olea; D006109:Poaceae / Q000378:metabolism; D012987:Soil; D013696:Temperature; D062065:Wastewater; D014874:Water Pollutants, Chemical / Q000378:metabolism; D018508:Water Purification / Q000379:methods*; D053833:Wetlands
chemical_list: D002857:Chromium; D007220:Industrial Waste; D012987:Soil; D062065:Wastewater; D014874:Water Pollutants, Chemical; C074702:chromium hexavalent ion
keywords: Chromium; Common reeds; Composting; HRT; HSF constructed wetlands