Chromium removal from wastewater using HSF and VF pilot-scale constructed wetlands: Overall performance, and fate and distribution of this element within the wetland environment.
The current experimental work aimed at the investigation of the overall chromium removal capacity of constructed wetlands (CWs) and the chromium fate-distribution within a wetland environment. For this purpose, the experimental setup included the parallel operation and monitoring of two horizontal subsurface flow (HSF) pilot-scale CWs and two vertical flow (VF) pilot-scale CWs treating Cr-bearing wastewater. Samples were collected from the influent, the effluent, the substrate and the plants. Apart from the continuous experiment, batch experiments (kinetics and isotherm) were conducted in order to investigate the chromium adsorption capacity of the substrate material. According to the findings, HSF-CWs demonstrated higher removal capacities in comparison to VF-CWs, while in both types the planted units indicated better performance compared to the unplanted ones. Analysis in various wetland compartments and annual mass balance calculation highlighted the exceptional contribution of substrate to chromium retention, while Cr accumulation in plant was not so high. Finally, experimental data fitted better to the pseudo-second-order and Langmuir models regarding kinetics and isotherm simulation.
Laboratory of Ecological Engineering and Technology, Department of Environmental Engineering, School of Engineering, Democritus University of Thrace, 67100 Xanthi, Greece. Electronic address: vpapaeva@nv.duth.gr.
Vassiliki A
VA
Papaevangelou
Laboratory of Ecological Engineering and Technology, Department of Environmental Engineering, School of Engineering, Democritus University of Thrace, 67100 Xanthi, Greece. Electronic address: ggkikas@env.duth.gr.
Georgios D
GD
Gikas
Centre for the Assessment of Natural Hazards and Proactive Planning & Laboratory of Reclamation Works and Water Resources Management, Department of Infrastructure and Rural Development, School of Rural and Surveying Engineering, National Technical University of Athens, Zografou, 15780 Athens, Greece. Electronic address: tsihrin@central.ntua.gr.
Vassilios A
VA
Tsihrintzis
D000327:Adsorption; D002857:Chromium / Q000032:analysis / Q000378:metabolism*; D004777:Environment; D052918:Environmental Restoration and Remediation; D060587:Groundwater / Q000737:chemistry*; D010944:Plants / Q000378:metabolism; D062065:Wastewater / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000737:chemistry*; D053833:Wetlands
D002857:Chromium; D062065:Wastewater; D014874:Water Pollutants, Chemical
Adsorption capacity; Chromium removal; Constructed wetlands; Freundlich and Langmuir isotherms; Mass balance; Plant uptake