Phosphorus is an element which exists naturally in the environment and is required for plant and animal life. Excess of phosphorus can cause significant environmental and health problems, namely eutrophication and the growth of toxic algal blooms in lakes and streams. Onsite wastewater treatment systems are a significant source of environmental phosphorus loading. This laboratory column study explored the use of a nano-enhanced reactive iron media for use in removing phosphorus in onsite wastewater treatment. Actual secondary treated wastewater was used. The capacity was determined to be between 29 and 47 mg P/g, considerably higher than other media that was examined using actual wastewater in a continuously operated reactor. The shape of the effluent removal curve indicates that the likely mechanism of removal is adsorption controlled by the equilibrium complexation of phosphorus with the nano-iron crystals attached the surface of the media. This research could not demonstrate statistically whether empty bed contact time or hydraulic loading were the most important parameters in determining the removal efficiency. As well, it was determined that a wastewater that supports the establishment of a biofilm produces spikes of effluent total phosphorus.
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