Determination of first-order rate constant for phosphorus removal in a novel model-reed bed treatment system

摘要

Two years performance data from a single laboratory scale reed bed system of constructed wetland receiving phosphorus rich animal farm wastewater under 'tidal flow' operation were used to compute the reaction rate constant 'k' for the parameters such as reactive phosphorus (RP) and soluble reactive phosphorus (SRP) based on first-order kinetics. The reed bed is novel in its substrate of using dewatered aluminum-flocculated drinking water treatment sludge to enhance phosphorus removal. The 'k' values were calculated using influent and effluent concentrations and an assumption of plug flow hydraulics. Effluent concentrations were reasonably correlated to influent concentrations for both RP (R2=0.82) and SRP (R2=0.37). The calculated rate constant 'k' of the firstorder plug flow kinetics model for RP of 17.1 d-1 and SRP of 19.8 d-1, respectively, were higher than those reported in the literature for farm wastewater treatment using reed bed system. This reflects the advantage regarding the treatment efficiency of such the alum sludge-based novel reed bed treatment system.