Earticle

본 연구에서는 시화호 산업단지 인근해역에 축적된 퇴적물 코어시료의 중금속 오염도 및 퇴적량에 대한 조사를 실시하였다. 중금 속의 평균농도(mg/kg)는 Zn(353)>Cu(151.7) >Cr(119) >Pb(78.6)>Ni(49.9) >As(10.8) >Cd(1.20) >Hg(0.091)의 농도 순이었다. 각 퇴적물 코어시료 내 중금속의 평균농도는 Cr, Ni, Cu, Zn, Pb, Hg은 정점 D에서, As와 Cd은 각각 정점 A와 C에서 최대농도를 나타 내어 토구의 유역면적이 큰 지역에서 상대적으로 높은 농도를 보였다. 농집지수(geo-accumulation index; Igeo)를 이용하여 금속 오염도를 평가한 결과, Cu와 Cd은 Moderately to highly polluted 상태였고, Ni, Zn, Hg은 Moderately polluted의 오염상태를 보였다 . Pb, Cr, As는 Moderately to unpolluted상태로 오염도가 상대적으로 낮은 것으로 나타났다. 분석된 8개 중금속을 우리나라 퇴적 물 주의기준(TEL)과의 비교를 통하여 퇴적물의 종합적인 질적평가(Sediment quality index by CCME)를 실시한 결과, 총 7개 코어 시료 중 5개시료(A, B, E, F, G)는 나쁨(Poor)의 등급, 중앙부인 2개 코어시료 (C, D)는 매우 나쁨(Very poor)에 해당되는 등급이었 다. 연구지역인 산업단지 인근 0.547 km2 면적의 68 cm 깊이에는 162,536 ton(dry weight)의 중금속에 오염된 퇴적물이 존재함을 알 수 있었다. 본 연구에서 분석된 8개 금속원소에 대한 총 퇴적량(ton)은 116.2 ton이었고, 이 중 Zn이 52.4 ton으로 가장 많은 부 분을 차지하고 있었고 Cu(22.8)>Cr(18.5)>Pb(12.7)>Ni(7.8)>As(1.72)>Cd(0.19)> Hg(0.014) 의 순으로 나타났다.

An assessment of pollution status and deposition for heavy metals in sediment core samples near highly industrialized area were carried out. The mean metal concentrations (mg/kg) occurred in the following order: Zn(353)>Cu(152)>Cr(119)>Pb(78.6)>Ni(49.9)>As(10.8)>Cd(1.20)>Hg(0.091). Cr, Ni, Cu, Zn, Pb and Hg were highest at St. D. The highest levels of As and Cd were observed at St. A and St. C. These indicate that the drainage area and input from industrial activities could affect metal pollution. Sediment cores have been found to be moderately to highly polluted for Cu and Cd; moderately polluted for Ni, Zn and Hg; moderately to unpolluted for Pb, Cr and As on the assessment of pollution status using geo-accumulation index. The results (sediment quality index; SQI) of assessment of sediment quality which was based on the TEL of Korea ranged from “poor” to “very poor” condition. It indicates that enormous metal pollutants were enter into the coastal region throughout sewer outlet. near industrial facilities 162,536 tons (dry weight) of highly polluted sediments had deposited in the study area (0.547 km2) with depth of 68cm. Total amount of deposition for 8 measured metals was 116.2 ton. Zn had the highest value (52.4 ton) and other metals decreased in the following order of Cu(22.8)>Cr(18.5)>Pb(12.7) >Ni(7.8)>As(1.72)>Cd(0.19)>Hg(0.014).

The optimal sediment remediation techniques for the western inner bays (Dangdong) of Jinhae Bay, Korea were studied. We performed selective removal of contaminated surface sediments and analysis of environmental improvement effect after spraying sand and sediment remediation agent from April 2015 to December 2016. In 2015, sediment oxygen demand of core samples was measured after 18 days of treatment with sand (1.73 Φ) or sand + microbial agents. In 2016, these treatments were done directly on the test-bed sediments. The combined effects of environmental dredging, sand capping and application of microbial agents were found to be outstanding for the sediment remediation in Jinhae Bay.

Metal biokinetic model was used to estimate the bioaccumulation of Cd and Zn in bivalves dwelling on the contaminated sediment of Yongho Bay, Korea. We also assessed the health risk for human population exposed to Cd by consuming these bivalves. Improved knowledge on the assimilation number, ingestion rate, efflux rate and growth rate in bivalves would be necessary for the construction of reliable ecosystem based tool for the management of contaminated sediments.