title: Assessment of long-term phosphorus retention in an integrated constructed wetland treating domestic wastewater.
abstract: Due to the nature of the phosphorus (P) removal mechanisms associated with constructed wetlands, the sustainability of P treatment is usually of high interest. As a result, a 4-year dataset from a typical multi-celled integrated constructed wetland (ICW) located at Glaslough in Co. Monaghan, Ireland was evaluated to determine the effects of long-term P loadings and hydrological inputs on P treatment. The ICW was intensively monitored year-round from February 2008 through March 2012 for total P and molybdate reactive phosphate (MRP). Domestic wastewater was loaded at 16.4 ± 0.96 g m(2) year(-1) for total P and 11.2 ± 0.74 g m(2) year(-1) for MRP. Average mass reductions over the monitoring period were 91.4 and 90.1%, respectively. The area-based kinetic coefficients (K(20)) of 11.8 for total P and 15.6 m year(-1) for MRP indicated a high area-specific retention rate. The ICW appeared to have a sustained capacity for P adsorption and retention, but the treatment was influenced mainly by external hydrological inputs and fluctuations in wastewater loadings. Linear regression analyses showed a reduction in mass retention of both total P and MRP with increased effluent flow volumes. Monthly mass reductions exceeded 90% when the effluent flow volumes were less than 200 m(3) day(-1). When monthly effluent flow volumes exceeded 200 m(3) day(-1), nonetheless, mass reductions became highly variable. Designs and management of ICW systems should adopt measures to limit external hydrological loadings in order to maintain sufficient P treatment.
authors: Centre for Water Resources Research, School of Civil, Structural and Environmental Engineering, Newstead Building, University College Dublin, Belfield, Dublin 4, Ireland, mawuli_dzkps@yahoo.com.au.
authors: Mawuli
authors: M
authors: Dzakpasu
authors: Miklas
authors: M
authors: Scholz
authors: Valerie
authors: V
authors: McCarthy
authors: Siobhán N
authors: SN
authors: Jordan
mesh_terms: D000327:Adsorption; D004784:Environmental Monitoring; D007494:Ireland; D010758:Phosphorus / Q000032:analysis*; D045483:Rivers; D062065:Wastewater / Q000032:analysis*; D018508:Water Purification; D053833:Wetlands
chemical_list: D010758:Phosphorus; D062065:Wastewater