자란만 패류양식해역의 퇴적물 특성 및 분포

Abstract

To understand the distributions and characteristics of organic matter and heavy metal concentrations in the surface sediment of Jaran Bay, we investigated the grain size, IL (Ignition Loss), COD (Chemical oxygen demand), and heavy metals (As, Cd, Cr, Cu, Ni, Pb, Zn) in surface sediments collected at 10 stations in this bay in August 2017. The grain size analysis indicate that surface sediment in Jaran Bay are characterized by Silt contents ranged from 70.4-81.0% (75.9%) and Clay content 19.0-29.6% (24.1%). IL of surface sediment range from 7.5-13.9% (10.3%) and COD was in the range of 4.2-18.8 mgO2/g (12.4 mgO2/g). A seven-element of surface sediments (As, Cd, Cr, Cu, Ni, Pb, Zn) were calculated by TEL (Threshold effect level), PEL (Probable effects level), Igeo (Geoaccumulation index). pollution load index (PLI) and ecosystem risk index (ERI). As a result of applying the marine environment standards TEL and PEL, Cu and Zn were slightly higher than the TEL standard values. However, all heavy metals were observed below the PEL standard values. Igeo also indicated that As showed 60% concerning moderate risk(Class 2). The pollution load index (PLI) for evaluating the total pollution level of trace metals was 0.9-1.1 (1.1), almost study area showed relatively high pollution(1.0) and The ecosystem risk index (ERI), was 63.7-81.8 (73.8), which was a low risk to all study area. The correlation matrix displays the existence of remarkable levels of correlation with both positive and negative values among different variable pairs. IL and COD showed no correlation. However, Pb and Zn values indicated strong positive values.