Martín-Torre M Camino, Cifrian Eva, Ruiz Gema, Galán Berta, Viguri Javier R
Green Engineering & Resources Research Group (GER), Department of Chemistry and Process & Resources Engineering, ETSIIT, University of Cantabria, Avda. de los Castros s/n, 39005, Santander, Cantabria, Spain.
Green Engineering & Resources Research Group (GER), Department of Chemistry and Process & Resources Engineering, ETSIIT, University of Cantabria, Avda. de los Castros s/n, 39005, Santander, Cantabria, Spain.
J Environ Manage. 2017 Sep 1;199:211-221. doi: 10.1016/j.jenvman.2017.05.044. Epub 2017 May 22.
Carbon dioxide (CO) Capture and Storage (CCS) is a technology to reduce the emissions of this gas to the atmosphere by sequestering it in geological formations. In the case of offshore storage, unexpected CO leakages will acidify the marine environment. Reductions of the pH might be also caused by anthropogenic activities or natural events such as acid spills and dredging operations or storms and floods. Changes in the pH of the marine environment will trigger the mobilisation of elements trapped in contaminated shallow sediments with unclear redox boundary. Trace element (As, Cd, Cr, Cu, Ni, Pb and Zn) release from anoxic and oxic estuarine sediment is analysed and modelled under different laboratory acidification conditions using HNO (l) and CO (g): acidification at pH = 6.5 as worst-case scenario in events of CO leakages and acid spills, and acidification at pH = 7.0 as a seawater scenario under CO leakages, acid spills, as well as sediment resuspension. The prediction of metal leaching behaviour appear to require sediment specific and site specific tools. In the present work it is demonstrated that the proposed three in-series reactions model predicts the process kinetics of the studied elements under different simulated environmental conditions (oxidation levels and acid sources). Differences between HNO and CO acidification are analysed through the influence of the CO gas on the ionic competition of the medium. The acidification with CO provokes higher released concentrations from the oxic sediment than from the anoxic sediment, except in the case of Zn, which influences the release of the other studied elements. Slight acidification can endanger the aquatic environment through an important mobilisation of contaminants. The obtained prediction of the contaminant release from sediment (kinetic parameters and maximum concentrations) can contribute to the exposure assessment stage for risk management and preincidental planning in accidental CO leakages and chemical spills scenarios.
二氧化碳（CO₂）捕集与封存（CCS）是一种通过将该气体封存于地质构造中来减少其向大气排放的技术。在海上封存的情况下，意外的CO₂泄漏会使海洋环境酸化。pH值的降低也可能由人为活动或自然事件引起，如酸液泄漏和疏浚作业，或风暴和洪水。海洋环境pH值的变化将引发被困在氧化还原边界不明的受污染浅层沉积物中的元素的迁移。在不同的实验室酸化条件下，使用HNO₃（l）和CO₂（g）对缺氧和有氧河口沉积物中微量元素（砷、镉、铬、铜、镍、铅和锌）的释放进行了分析和建模：pH = 6.5时的酸化作为CO₂泄漏和酸液泄漏事件中的最坏情况，pH = 7.0时的酸化作为CO₂泄漏、酸液泄漏以及沉积物再悬浮情况下的海水情景。金属浸出行为的预测似乎需要沉积物特定和场地特定的工具。在本研究中表明，所提出的三级串联反应模型能够预测在不同模拟环境条件（氧化水平和酸源）下所研究元素的过程动力学。通过CO₂气体对介质离子竞争的影响，分析了HNO₃和CO₂酸化之间的差异。除锌的情况外，CO₂酸化引发的有氧沉积物释放浓度高于缺氧沉积物，而锌会影响其他所研究元素的释放。轻微酸化可能通过污染物的大量迁移危及水生环境。从沉积物中获得的污染物释放预测（动力学参数和最大浓度）有助于在CO₂意外泄漏和化学品泄漏情景下进行风险管理的暴露评估阶段和事前规划。
