Department of Chemistry, Mississippi State University, MS 39762, USA.
Universidad de Buenos Aires, Facultad de Agronomía, Departamento de Recursos Naturales y Ambiente, Cátedra de Botánica General, Av. San Martín 4453, C1417DSE, Buenos Aires, Argentina.
J Hazard Mater. 2023 Feb 5;443(Pt B):130257. doi: 10.1016/j.jhazmat.2022.130257. Epub 2022 Oct 26.
Molybdenum (Mo) is a naturally-occurring trace element in drinking water. Most commonly, molybdate anions (MoO) are in well water and breast milk. In addition, it is used in medical image testing. Recently, the EPA classified Mo as a potential contaminant, as exposure can lead to health effects such as gout, hyperuricemia, and even lung cancer. We have assessed the sorptive removal of aqueous molybdate using Douglas fir biochar (DFBC) and a hybrid DFBC/FeO composite containing chemically-coprecipitated iron oxide (FeO). Adsorption was studied at various: pH values, equilibrium times (5 min-24 h), initial Mo concentrations (2.5-1000 mg/L), and temperatures (5, 25, and 40 °C) using batch sorption and fixed-bed column equilibrium methods. Langmuir capacities for DFBC and DFBC/FeO (at pH 3, 2 hrs equilibrium) were within 459.3-487.9 mg/g and 288-572 mg/g, respectively. These adsorbents and their Mo-laden counterparts were characterized by elemental analysis, BET, PZC, SEM, TEM, EDS, XRD, and XPS. MoO adsorption on DFBC is thought to be governed primarily via electrostatic attraction. Adsorption by DFBC/FeO is primarily governed by chemisorption onto magnetite surface hydroxyl groups, while electrostatics prevail in the DFBC-exposed phase. Stoichiometric precipitation of iron molybdates triggered by iron dissolution was also considered. The data suggest that DFBC and DFBC/FeO are promising candidates for molybdate sorption.
钼（Mo）是饮用水中天然存在的痕量元素。通常情况下，钼酸盐阴离子（MoO）存在于井水和母乳中。此外，它还用于医学影像检测。最近，EPA 将钼归类为一种潜在的污染物，因为接触钼可能会导致健康影响，如痛风、高尿酸血症，甚至肺癌。我们已经评估了使用花旗松生物炭（DFBC）和含有化学共沉淀氧化铁（FeO）的混合 DFBC/FeO 复合材料对水溶液中钼酸盐的吸附去除效果。通过批处理吸附和固定床柱平衡方法，在不同的 pH 值、平衡时间（5 分钟-24 小时）、初始钼浓度（2.5-1000mg/L）和温度（5、25 和 40°C）下研究了吸附作用。DFBC 和 DFBC/FeO 的 Langmuir 容量（在 pH 3、2 小时平衡时）分别为 459.3-487.9mg/g 和 288-572mg/g。这些吸附剂及其负载钼的对应物通过元素分析、BET、PZC、SEM、TEM、EDS、XRD 和 XPS 进行了表征。DFBC 上 MoO 的吸附主要归因于静电吸引。DFBC/FeO 的吸附主要归因于磁铁矿表面羟基上的化学吸附，而静电作用在暴露于 DFBC 的相中占主导地位。同时也考虑了由铁溶解引发的铁钼酸盐的化学计量沉淀。数据表明，DFBC 和 DFBC/FeO 是钼酸盐吸附的有前途的候选材料。
