In this study, a side-by-side comparison of two pilot-scale vertical subsurface flow constructed wetlands (6.2 m(2)×0.85 m, q(i)=95 L/m(2) d, τ(n)=3.5 d) handling primary treated domestic sewage was conducted. One system (VA-i) was set to intermittent aeration while the other was aerated continuously (VAp-c). Intermittent aeration was provided to VA-i in an 8 h on/4 h off pattern. The intermittently aerated wetland, VA-i, was observed to have 70% less nitrate nitrogen mass outflow than the continuously aerated wetland, VAp-c. Intermittent aeration was shown to increase treatment performance for TN while saving 33% of running energy cost for aeration. Parallel tracer experiments in the two wetlands showed hydraulic characteristics similar to one Continuously Stirred Tank Reactor (CSTR). Intermittent aeration did not significantly affect the hydraulic functioning of the system. Hydraulic efficiencies were 78% for VAp-c and 76% for VA-i.
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http://dx.doi.org/10.1016/j.biortech.2014.03.100 | DOI Listing |
Environ Sci Pollut Res Int
December 2024
Department of Civil Engineering, Indian Institute of Technology Guwahati, Guwahati, Assam, 781039, India.
The current research assessed the effectiveness of four hybrid constructed wetland (HCW) systems for the remediation of synthetic dye wastewater with Reactive Black 5 (RB5) azo dye. All HCW systems had identical configurations, consisting of a horizontal CW followed by a vertical CW, and operated under diverse conditions such as the presence of plants (Typha angustifolia), feeding modes (batch and continuous) and intermittent aeration (4 h day). Anaerobic-aerobic conditions simulated within the HCW systems were crucial in removing the pollutants from synthetic dye wastewater.
View Article and Find Full Text PDFJ Hazard Mater
December 2024
Department of Environmental Science, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, PR China; The Key Laboratory of Water and Sediment Sciences (Peking University), Ministry of Education, Beijing 100871, PR China. Electronic address:
The reactive substance consisting manganese oxides (MnOx) and solid carbon have been reported to be effective in polishing secondary wastewater; however, the treatment characteristics and mechanism remains limited. In this study, MnOx/carbon (Mn-C) composites were applied in biofilters to evaluate simultaneous removal of nitrate and sulfamethoxazole (SMX), with the single carbon composites as control. Results showed that the effluent concentrations of NO-N and SMX were below 2.
View Article and Find Full Text PDFChemosphere
December 2024
Federal University of Tecnhology - Paraná (UTFPR) - Civil Construction Academic Department, Deputado Heitor de Alencar Furtado St., 5000, Ecoville, 81280-340, Curitiba, Paraná, Brazil. Electronic address:
Operational strategies have been applied in constructed wetlands to optimize the removal of nutrients and hormones that are still a concern in wastewater treatment. The strategy of intensifying intermittent aeration was investigated in two microcosm-scale vertical-flow constructed wetlands (VFCWs) planted with Eichhornia crassipes onto autoclaved aerated concrete (AC) in the removal of nutrients, estrone (E1), 17β-estradiol (E2) and 17α-ethinylestradiol (EE2). CW-1 (2.
View Article and Find Full Text PDFWater Sci Technol
December 2024
Department of Information Engineering and Computer Science, University of Trento, via Sommarive 9, Trento 38123, Italy.
The increasing use of intermittent aeration controllers in wastewater treatment plants (WWTPs) aims to reduce aeration costs via continuous ammonia and oxygen measurements but faces challenges in detecting sensor and process anomalies. Applying machine learning to this unbalanced, multivariate, multiclass classification challenge requires much data, difficult to obtain from a new plant. This study develops a machine learning algorithm to identify anomalies in intermittent aeration WWTPs, adaptable to new plants with limited data.
View Article and Find Full Text PDFSci Total Environ
December 2024
Institute of Plant Ecology (IFZ), Justus-Liebig University, Giessen, Germany; Liebig Centre for Agroecology and Climate Impact Research, Justus Liebig University, Germany; School of Biology and Environmental Science and Earth Institute, University College Dublin, Dublin, Ireland.
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