Department of Civil Engineering & Geological Sciences and Department of Electrical Engineering, University of Notre Dame , Notre Dame, Indiana 46556, United States.
Environ Sci Technol. 2011 Apr 15;45(8):3231-7. doi: 10.1021/es1026135. Epub 2011 Feb 4.
This study focused on the effects of particle size (40, 8.6, and 3.6 nm) and the presence of the microbial ligand desferrioxamine B (DFOB) on Pb(II) sorption to hematite, based on sorption edge experiments (i.e., sorption as a function of pH). Effects of hematite nanoparticle size on sorption edges, when plotted either as sorption density or as % Pb uptake, depended on whether the experiments were normalized to account for differences in specific surface area within the reaction vessels or postnormalized after the fact. Accounting for specific surface area within reaction vessels is needed to maintain comparable ratios of sorbate to sorbent surface sites. When normalized for BET specific surface area (A(s,BET)) within the reaction vessels, the Pb(II) sorption edge shifted ∼0.5 pH units to the left for <10 nm hematite particles, but maximum sorption density (at pH ≥ 6) was unaffected by particle size. DFOB had little or no effect on Pb(II) sorption to <10 nm particles, but DFOB decreased Pb(II) sorption to the 40 nm particles at pH ≥ 6 by ∼20%. Hematite (nano)particle size thus exerts subtle effects on Pb(II) sorption, but the effects may be more pronounced in the presence of a metal complexing agent.
本研究主要关注粒径（40、8.6 和 3.6nm）和微生物配体去铁胺 B（DFOB）的存在对针铁矿中 Pb(II)吸附的影响，研究基于吸附边缘实验（即，吸附与 pH 的关系）。当以吸附密度或 Pb 吸收百分比为指标绘制针铁矿粒径对吸附边缘的影响时，取决于实验是否归一化以考虑反应容器内比表面积的差异，或者在事实发生后进行后归一化。需要在反应容器内考虑比表面积以保持吸附质与吸附剂表面位点的可比比例。当根据反应容器内 BET 比表面积 (A(s,BET)) 归一化时，<10nm 针铁矿颗粒的 Pb(II)吸附边缘向左移动约 0.5 pH 单位，但粒径对最大吸附密度（pH≥6）没有影响。DFOB 对<10nm 颗粒中 Pb(II)的吸附几乎没有影响，但 DFOB 在 pH≥6 时使 40nm 颗粒中 Pb(II)的吸附减少了约 20%。因此，针铁矿（纳米）颗粒尺寸对 Pb(II)的吸附有细微影响，但在存在金属络合剂的情况下，这种影响可能更为显著。
