School of Planning, Architecture & Civil Engineering, Queen's University Belfast, David Keir Building, Stranmillis Road, Belfast BT9 5AG N Ireland, UK.
Environ Sci Technol. 2012 Mar 6;46(5):2583-91. doi: 10.1021/es202048c. Epub 2012 Feb 15.
Particulate colloids often occur together with proteins in sewage-impacted water. Using Bovine Serum Albumin (BSA) as a surrogate for protein in sewage, column experiments investigating the capacity of iron-oxide coated sands to remove latex microspheres from water revealed that microsphere attenuation mechanisms depended on antecedent BSA coverage. Dual pulse experiment (DPE) results suggested that where all BSA was adsorbed, subsequent multiple pore volume microsphere breakthrough curves reflected progressively reduced colloid deposition rates with increasing adsorbed BSA content. Modeling colloid responses suggested adsorption of 1 μg BSA generated the same response as blockage by between 7.1 × 10(8) and 2.3 × 10(9) deposited microspheres. By contrast, microsphere responses in DPEs where BSA coverage of the deposition sites approached/reached saturation revealed the coated sand maintained a finite capacity to attenuate microspheres, even when incapable of further BSA adsorption. Subsequent microsphere breakthrough curves demonstrated the matrix's colloid attenuation capacity progressively increased with continued microsphere deposition. Experimental findings suggested BSA adsorption on the sand surface approaching/reaching saturation generated attractive deposition sites for colloids, which became progressively more attractive with further colloid deposition (filter ripening). Results demonstrate that adsorption of a single type of protein may either enhance or inhibit colloid mobility in saturated porous media.
颗粒胶体经常与污水中的蛋白质一起存在。使用牛血清白蛋白（BSA）作为污水中蛋白质的替代物，通过柱实验研究了氧化铁涂层砂从水中去除乳胶微球的能力，结果表明微球的衰减机制取决于 BSA 的覆盖程度。双脉冲实验（DPE）的结果表明，当所有 BSA 都被吸附时，随后的多个孔隙体积微球穿透曲线反映出随着吸附 BSA 含量的增加，胶体沉积速率逐渐降低。胶体响应的建模表明，吸附 1μg 的 BSA 产生的响应与 7.1×10(8)到 2.3×10(9)个沉积微球的堵塞相同。相比之下，在 DPE 中，当沉积位点的 BSA 覆盖率接近/达到饱和时，微球的响应表明，即使不能进一步吸附 BSA，涂层砂仍能保持有限的衰减微球的能力。随后的微球穿透曲线表明，随着微球的持续沉积，基质的胶体衰减能力逐渐增加。实验结果表明，BSA 在砂表面的吸附接近/达到饱和会产生对胶体有吸引力的沉积位点，随着胶体的进一步沉积（滤饼成熟），这些沉积位点的吸引力会逐渐增加。结果表明，在饱和多孔介质中，单一类型蛋白质的吸附可能会增强或抑制胶体的迁移能力。
