Air pollution-aerosol interactions produce more bioavailable iron for ocean ecosystems.
Air pollution-aerosol interactions produce more bioavailable iron for ocean ecosystems.
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DOI：
10.1126/sciadv.1601749
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发表时间：
2017-03
期刊：
影响因子：
13.6
通讯作者：
Shi Z
中科院分区：
文献类型：
--
作者：
Li W;Xu L;Liu X;Zhang J;Lin Y;Yao X;Gao H;Zhang D;Chen J;Wang W;Harrison RM;Zhang X;Shao L;Fu P;Nenes A;Shi Z
酸性空气污染物将铁溶解在气溶胶中，使海洋肥沃。长期以来，人们一直假设人为污染物和自然排放物形成的酸溶解了空气中颗粒物中的铁（Fe），从而增加了海洋中生物可利用铁的供应。然而，实地观察尚未提供无可争议的证据来证实这一假设。对东海上空数百个大气颗粒物的单颗粒化学分析表明，燃煤和钢铁工业产生的富铁颗粒物在大气中停留1 ~ 2天后，表面被一层厚厚的硫酸盐覆盖。老化颗粒中的Fe作为（不溶性）铁氧化物的“热点”存在，并且以（可溶性）Fe硫酸盐的形式贯穿酸性硫酸盐涂层，其随着老化程度（涂层厚度）而增加。这为酸性铁溶解提供了“确凿的证据”，因为在新排放的颗粒物中没有检测到硫酸铁，而且大气中没有硫酸铁形成的其他来源或机制。
Acidic air pollutants dissolve iron in aerosols and fertilize the ocean. It has long been hypothesized that acids formed from anthropogenic pollutants and natural emissions dissolve iron (Fe) in airborne particles, enhancing the supply of bioavailable Fe to the oceans. However, field observations have yet to provide indisputable evidence to confirm this hypothesis. Single-particle chemical analysis for hundreds of individual atmospheric particles collected over the East China Sea shows that Fe-rich particles from coal combustion and steel industries were coated with thick layers of sulfate after 1 to 2 days of atmospheric residence. The Fe in aged particles was present as a “hotspot” of (insoluble) iron oxides and throughout the acidic sulfate coating in the form of (soluble) Fe sulfate, which increases with degree of aging (thickness of coating). This provides the “smoking gun” for acid iron dissolution, because iron sulfate was not detected in the freshly emitted particles and there is no other source or mechanism of iron sulfate formation in the atmosphere.