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| 珠江口淇澳岛海岸带沉积物中硫酸盐还原与不同形态硫分布 |
| Sulfate reduction and reduced sulfur speciation in coastal sediments of Qi’ao island, the Pearl River estuary |
| 投稿时间：2009-04-15 修订日期：2009-08-16 |
| DOI： |
| 中文关键词: 硫酸盐还原，甲烷厌氧氧化（AOM），挥发性硫（AVS），黄铁矿，有机硫，甲烷 |
| 英文关键词:Sulfate reduction flux, Anaerobic oxidation methane(AOM), Acid volatile sulfur(AVS), Pyrite,Organic sulfur, Methane |
| 基金项目: |
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| 中文摘要: |
| 摘要：
本文对珠江口淇澳岛海岸带三个站位（QA-11，QA-9 和 QA-14）沉积物中不同形态的硫（酸可挥发性硫，黄铁矿和有机硫）、有机碳（TOC）和孔隙水中SO42－、CH4进行测定，并利用稳态扩散模型计算其中两个站位（QA-9和QA-14）硫酸盐还原通量（1.74 和 1.14mmol m-2 d-1）和甲烷厌氧氧化（AOM）通量（0.34 和 0.29 mmol m-2 d-1）。研究结果表明由于潮间带沉积物受到SO42－ 供给的限制， QA-11站位硫酸盐还原带较浅（约16 cm）。潮下带从QA-9至QA-14站位，随距离海岸和水深的增加，硫酸盐还原通量呈现减小趋势，硫酸还原可能逐渐受可用活性有机质的控制；同时，AOM对硫酸还原的贡献增加趋势，由19.2％增加至25.5％。三个站位沉积物中不同形态还原硫含量为：有机硫（OS）>黄铁矿（Fe2S）>酸可挥发性硫（AVS）。沉积物中AVS的空间分布与硫酸盐还原通量存在正相关性。QA-11和QA-14站位（Pyrite-S）/AVS 比值分别为7.9 和3.6，表明两个站位黄铁矿形成可能受硫酸盐还原作用的限制。QA-9站位（Pyrite-S）/AVS 比值为2.2，暗示AVS向黄铁矿转化受到可利用活性铁限制。 |
| 英文摘要: |
| Abstract:
The concentrations of methane and sulfate in porewater and pools of reduced sulfur compounds (Acid volatile sulfur, pyrite and organic sulfur) and total organic carbon (TOC) in sediment were determined at three sites (QA-11, QA-9 and QA-14) in shore sediments of Qi’ao Island, PRE. By steady state diffusive model，sulfate reduction and anaerobic oxidation methane flux were calculated from pore water sulfate and methane profiles. The values of sulfate reduction flux equaled to 1.74 and 1.14mmol m-2 d-1 at sites QA-9 and QA-14, and methane anaerobic flux with 0.34 and 0.29 mmol m-2 d-1 respectively. Because the sulfate supply from overlying water is limited in intertide sediment, the depth of sulfate reduction zone is shallow at QA-11 site. With the increasing the distance from coast and seawater depth, the values of sulfate reduction flux gradually decreased from QA-9 to QA-14 sites located subtidal zone, sulfate reduction might be controlled by the supply of organic substrates in subtidal zone sediment, meanwhile sulfate reduction occurring by AOM increased from 19.2 to 25.5％. The results showed that the content of reduced sulfur in sediment followed the order of organic sulfur>pyrite>acid volatile sulfur. The concentration of AVS and sulfate reduction flux showed obvious correlation in sedimentary cores of three sites. The value of Pyrite-S/AVS were 7.9 and 3.6 at QA-11 and QA-14 sites respectively, suggested that AVS could be transformed to pyrite efficiently and sulfate reduction was likely to be limiting formation pyrite in the sediments, and Pyrite-S/AVS ratio was 2.2 at QA-9 site indicated that sulfide mineralization was limited by the availability of highly reactive iron. |
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