Remediation of Feedlot Nutrients Runoff by Electrocoagulation Process

Abstract

Nutrient runoff from Concentrated Animal Feeding Operations (CAFOs) may cause ground and surface water pollution. Scientists and researchers are continually searching for appropriate technologies to mitigate feedlot nutrient runoff pollution. In this study, suitability of electrocoagulation treatment process was examined under laboratory conditions to mitigate nutrient pollutants from the feedlot runoff. Feedlot runoff was treated with three different type of electrodes such as aluminum (Al-Al), iron (Fe-Fe) and hybrid (Al-Fe) at different electrical voltage potentials (5, 10 and 15 Volts) for a designated time step (up to 30 min). The electrocoagulation cell consisted of two parallel rectangular plate electrodes, immersed in a beaker with 500 mL feedlot runoff and powered by a Direct Current (DC) supply. This study was conducted in batches at room temperature. Results indicated that Electrical Conductivity (EC), Total Phosphorus (TP), Total Nitrogen (TN) and Chemical Oxygen Demand (COD) concentration reduced significantly irrespective of electrode types. Overall, TP concentration reduction was higher (100%) followed by COD (50-75%) and TN (25-60%) concentration. Nutrient removal and specific electrical energy consumption increased with increasing voltage level. Aluminum electrodes were more effective than the other two electrodes for TP reduction at all applied potentials and COD reduction was better at lower applied potential. Hybrid electrodes (Al-Fe) reduced TN better than the other two electrodes.