Adsorption of Nitrate and Phosphate onto the Dredged Sediment from a Coastal Fishery

Sun, Young Chul; Kim, Myoung-Jin; Song, Young-Chae

Journal of Navigation and Port Research 2012;36(6):459-463.
Published online August 31, 2012.

연안어장 준설퇴적물에 대한 질산염과 인산염의 흡착

선영철, 김명진, 송영채

Adsorption of Nitrate and Phosphate onto the Dredged Sediment from a Coastal Fishery

Young Chul Sun, Myoung-Jin Kim, Young-Chae Song

Abstract

In the present study, experiments have been performed to investigate the effects of the type of adsorbent, pH, and ionic strength on the adsorption of nutrients (nitrate and phosphate in artificial solution) onto the dredged sediment from a coastal fishery. In addition, this study aims to evaluate the possibility of removing the nutrients from the water using the dredged sediment. In the adsorption experiments of the nutrients, the reactions were completed within 10 minutes using NO^3--N(100 μM, 10mM) and PO₄^3--P(100 μM, 10mM). In the steady state, 61% and 77% of the initial amounts were removed respectively for 100 μM NO^3--N and 100 μM PO₄^3--P. The thermal treatment of the dredged sediment at 900 ℃ was not helpful to increase the removal efficiencies of the nutrients. Additives such as CaO and MgO dropped the removal efficiency of NO^3-to 0%, but increased that of PO₄^3-up to 98%. Adsorption isotherms of NO^3- and PO₄^3- could be explained by the Freundlich equation (R²>0.99). The adsorption reaction was little influenced by the pH and ionic strength. Based on the results showing short reaction time and considerably high removal efficiencies of the nutrients, it is proposed to apply the dredged sediment from a coastal fishery to removing nutrients such as nitrate and phosphate in the water.

Key Words: nitrate;phosphate;adsorption;nutrient;dredged sediment;coastal fishery