Removal of Nitrate Nitrogen in Activated Carbon with Calcium Treatment

Abstract

As chemical fertilizers have been applied to farmlands beyond the environmental capacity, leaching of nitrate nitrogen (NO₃-N) have been causing severe problems, such as groundwater contamination or eutrophication in water systems of watersheds. Also, high concentration of nitrate nitrogen in groundwater happens to affect human health, especially on infant. So, research interests have been focused on the effective measures for eliminating nitrate nitrogen leaching from farmlands. This study dealt with the strategy on removal of nitrate nitrogen from farmlands through the column experiment using activated carbon (charcoal) with calcium chloride (CaCl₂) treatment. In the experiments, 2 types of activated carbon were prepared; one was activated carbon with calcium chloride (CaCl₂) treatment and the other activated carbon without treatment. The experiment was conducted to corroborate the removal of nitrate nitrogen between 2 types of activated carbon and to quantify the amounts of activated carbon added for certain amounts of nitrate nitrogen removal. Glass beads, around 1.1 mm in diameter, were used as an alternative soil and incorporated with activated carbon at 10, 20 and 30% by volumetric basis. The experimental results indicated that average adsorption ratio of the columns with 20% and 30% of CaCl₂ treated carbon was larger than that of other columns, as initial adsorption ratio of the columns with 20% and 30% of CaCl₂ treated carbon was much higher than other columns. However, decreasing tendency in adsorbing NO₃-N of the columns with CaCl₂ treated carbon was comparatively higher than that of other columns.