Processes of nickel and cobalt uptake by a manganese oxide forming sediment in Pinal Creek, globe mining district, Arizona
Processes of nickel and cobalt uptake by a manganese oxide forming sediment in Pinal Creek, globe mining district, Arizona
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DOI：
10.1021/es010514d
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发表时间：
2001-12-15
影响因子：
11.4
通讯作者：
O'Day, PA
中科院分区：
文献类型：
--
作者：
Kay, JT;Conklin, MH;O'Day, PA
一系列的柱实验进行了使用锰氧化物涂层沉积物收集的hyporheic区在皮纳尔溪（AZ），金属污染的流，研究的吸收和保留的Mn，Ni，和Co。实验变量包括活性锰氧化细菌的存在和存在（非生物），不存在和存在的溶解敏，和沉积物锰氧化物含量。在生物条件下的Mn的吸收比在非生物条件下高8和39%之间。从柱沉积物的提取中可以看出，由于生物氧化，持续吸收Min。锰的吸收被假设为最初发生的吸附，导致随后的表面和/或微生物氧化。在100孔体积内完全突破Ni表明没有连续吸收的过程，并被建模为平衡吸附过程。在溶解的Mn存在下的镍吸收是67-100%可逆的。沉积物提取表明，镍吸收发生通过弱和强吸附。钴的连续吸收增加与沉积物中的氧化锰含量，和钴的吸收高达75%以上的生物比非生物条件下。钴的吸收控制现有的和新形成的锰氧化物。只有少量的Co吸收是可逆的（10-25%）。XANES光谱分析表明，大多数Co（II）被氧化为Co（III），并可能在结构上纳入锰氧化物。虽然锰氧化物的主要阶段控制的吸收和保留的最小值，镍，钴，金属之间的机制各不相同。
A series of column experiments was conducted using manganese oxide coated sediments collected from the hyporheic zone in Pinal Creek (AZ), a metal-contaminated stream, to study the uptake and retention of Mn, Ni, and Co. Experimental variables included the absence (abiotic) and presence (biotic) of active Mn-oxidizing bacteria, the absence and presence of dissolved Min, and sediment manganese oxide content. Uptake of Mn under biotic conditions was between 8 and 39% higher than under abiotic conditions. Continuous uptake of Min due to biotic oxidation was evident from extraction of column sediments. Manganese uptake is hypothesized to initially occur as adsorption, which led to subsequent surface and/or microbial oxidation. Complete breakthrough of Ni within 100 pore volumes indicated no process of continuous uptake and was modeled as an equilibrium adsorption process. Nickel uptake in the presence of dissolved Mn was 67-100% reversible. Sediment extractions suggest that Ni uptake occurred through weak and strong adsorption. Continuous uptake of cobalt increased with sediment manganese oxide content, and Co uptake was up to 75% greater under biotic than abiotic conditions. Cobalt uptake was controlled by both existing and newly formed manganese oxides. Only a small amount of Co uptake was reversible (10-25%). XANES spectral analysis indicated that most Co(ll) was oxidized to Co(III) and probably incorporated structurally into manganese oxides. Although manganese oxides were the primary phase controlling uptake and retention of Min, Ni, and Co, the mechanisms varied among the metals.