Automated ultrafiltration device for efficient collection of environmental nanoparticles from aqueous suspensions

Environmental nanoparticles exist in the hydrosphere, pedosphere, biosphere, and atmosphere. Their biogeochemical and ecological impacts are some of the fastest growing areas of research today. However, efficient separation of environmental nanoparticles remains difficult. The objective of this study was to develop an automated ultrafiltration device (AUD) for efficient collection of environmental nanoparticles. The AUD utilizes an automated hydraulic ram to facilitate collection of nanoparticles using the ultrafiltration membrane with pore size in the range of 1 to 100 nm. Zeolite A was used as a model nanoparticle sample to demonstrate the efficiency of the AUD. The size distribution and mean particle sizes determined by zeta-sizer analysis on the collected nanoparticles and their transmission electron micrographs indicated the adequacy of the AUD developed in this study in collecting nanoparticles (1-100 nm). Because of its ability to reduce the time needed for sample collection, coupled with the quantity of nanoparticles collected, the AUD was far more efficient than the conventional syringe method for collecting nanoparticles. The AUD has the characteristics of automation, easy operation, and high efficiency in the separation ofnanopartides and would, thus, facilitate future research and developments in environmental nanoscience and nanotechnology and their impacts on the ecosystem. Abbreviations: AUD, automated ultrafiltration device; DDW, double deionized water; TEM, transmission electron microscope. doi: 10.2136/sssaj2008.0376