Column Tests for Simulation of Phosphorus Fate and Transport and Evaluation of Life Expectancy of a Wastewater Land Treatment System

Currently, a reliable method for predicting the remaining life expectancy (RLE) of a land treatment system is not available. Hu (2005) concluded column studies by intermittently loading columns with a high influent P concentration to simulate P adsorption capacity and the low hydraulic loading rate conditions in the field. The objectives of this study were to: (1) further verify Hu's methodology, (2) evaluate P fate and transport in these columns, and (3) improve the existing model for predicting the RLE. Column tests were conducted under different influent P concentrations (e.g., 3000, 1000, 500, and 100 mg-P/L), and P breakthrough in each column was monitored. The results indicate that the predictions of the RLE of the Muskegon system were very similar for the three different influent P concentrations, but varied with soil types. Therefore, loading a short column packed with field soil intermittently with a high influent P concentration may be an efficient way to accelerate the process that might occur in the field and to predict the life expectancy of a wastewater land treatment system.