Metal release from contaminated coastal sediments under changing pH conditions: Implications for metal mobilization in acidified oceans.
To investigate the impacts and processes of CO2-induced acidification on metal mobilization, laboratory-scale experiments were performed, simulating the scenarios where carbon dioxide was injected into sediment-seawater layers inside non-pressurized chambers. Coastal sediments were sampled from two sites with different contamination levels and subjected to pre-determined pH conditions. Sediment samples and overlying water were collected for metal analysis after 10-days. The results indicated that CO2-induced ocean acidification would provoke increased metal mobilization causing adverse side-effects on water quality. The mobility of metals from sediment to the overlying seawater was correlated with the reduction in pH. Results of sequential extractions of sediments illustrated that exchangeable metal forms were the dominant source of mobile metals. Collectively, our data revealed that high metal concentrations in overlying seawater released from contaminated sediments under acidic conditions may strengthen the existing contamination gradients in Maluan Bay and represent a potential risk to ecosystem health in coastal environments.
Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, 1799 Jimei Boulevard, Xiamen City 361021, China. Electronic address: zswang@iue.ac.cn.
Zaosheng
Z
Wang
Key Laboratory of Tropical Marine Environmental Dynamics, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China.
Yushao
Y
Wang
Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, 1799 Jimei Boulevard, Xiamen City 361021, China.
Peihong
P
Zhao
Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, 1799 Jimei Boulevard, Xiamen City 361021, China; School of Environment, Northeast Normal University, Changchun 130117, China.
Liuqin
L
Chen
Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, 1799 Jimei Boulevard, Xiamen City 361021, China. Electronic address: czyan@iue.ac.cn.
Changzhou
C
Yan
Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, 1799 Jimei Boulevard, Xiamen City 361021, China.
Yijun
Y
Yan
Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, 1799 Jimei Boulevard, Xiamen City 361021, China.
Qiaoqiao
Q
Chi
D002245:Carbon Dioxide / Q000737:chemistry*; D002681:China; D017753:Ecosystem; D019015:Geologic Sediments / Q000032:analysis / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D008670:Metals / Q000032:analysis / Q000737:chemistry*; D009792:Oceans and Seas; D012623:Seawater / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000737:chemistry; D060753:Water Quality
D008670:Metals; D014874:Water Pollutants, Chemical; D002245:Carbon Dioxide
CO(2)-induced acidification; Contaminated sediment; Metal mobilization; Release rate; Water quality