Performance of Four Full-Scale Artificially Aerated Horizontal Flow Constructed Wetlands for Domestic Wastewater Treatment

Abstract

A comparison of the performance of four full-scale aerated horizontal flow constructed wetlands was conducted to determine the efficacy of the technology on sites receiving high and variable ammonia loading rates not yet reported in the literature. Performance was assessed in terms of ammonia and solids removal, hydraulic conductivity and mixing patterns. The capability of systems to produce ammonium effluent concentrations <3 mgNH 4 + -N/L was observed across all sites in systems receiving variable loadings between 0.1 and 13.0 gNH 4 + -N/m 2 /d. Potential resilience issues were observed in relation to response to spike loadings posited to be due to an insufficient nitrifying population within the beds. Hydraulic conductivity and flow mixing patterns observed suggested deterioration of the reactor effective volume over time. Overall, the study demonstrates the efficacy of the technology where ammonium removal is required on small sites receiving high and variable flow rates, with adequate removal of organics and solids, but no significant benefit to the long term hydraulics of the system.

उपचार आर्द्रभूमियााँ

“…In recent decades, use of active aeration (e.g., an air pump connected to a subsurface network of air distribution pipes) has been applied to HF wetlands (Wallace, 2001;Higgins, 2003;Ouellet-Plamondon et al, 2006;Maltais-Landry et al, 2009;Butterworth et al, 2016) as well as saturated VF wetlands (Murphy and Cooper, 2011;Wallace and Liner, 2011;van Oirschot et al, 2015). In the UK, over 40 tertiary treatment HF wetlands have been successfully retrofitted with aeration systems to increase treatment capacity and extend asset life (Murphy et al, 2016).…”

Effectiveness and Temporal Variation of a Full-Scale Horizontal Constructed Wetland in Reducing Nitrogen and Phosphorus from Domestic Wastewater

“…Due to usually long retention times, HSSF-CWs can provide a reliable secondary level of treatment, and it has been shown that they are effective in removing total suspended solids (TSS) and organic matter (OM), and also allow the removal of nutrients, although with variable and lower efficiencies [5][6][7].…”

Seasonal Variation of Nutrient Removal in a Full-Scale Artificial Aerated Hybrid Constructed Wetland

“…Furthermore, AA improves the resistance of CWs to the fluctuating influent loads [13] and intensifies mineralization of solids to prevent clogging of the system, and thus increases the lifespan of CWs [13,21]. Studies on AA in CWs have been conducted mostly in short-term laboratory-scale and pilot scale experiments, but very few experiments focused on long-term full-scale systems or its integration in hybrid CWs [7,13,22]. Moreover, seasonal variations of nutrient removal in aerated full-scale hybrid systems still remain unclear.…”