Comparison of Small- and Large-scale Ultrafiltration Systems for Organic Carbon and Metals in Freshwater at Low Concentration Factor

• Published in: Water, air, and soil pollution air, and soil pollution, 2008-01, Vol.187 (1-4), p.343-351
• Main Authors: Kottelat, R., Vignati, D.A.L., Chanudet, V., Dominik, J.
• Format: Article
• Language: English
• Subjects: Analysis methods; Analytical chemistry; Applied sciences; Aquatic environment; Atmospheric Protection/Air Quality Control/Air Pollution; Carbon; Chemistry; Chromium; Climate Change/Climate Change Impacts; Colloids; Comparative analysis; Contamination; Dissolved organic carbon; Earth and Environmental Science; Earth sciences; Earth, ocean, space; Environment; Environmental monitoring; Exact sciences and technology; Fractionation; Freshwater ecology; General, instrumentation; Geochemistry; Geochemistry: general, methodology, regional studies; Heavy metals; Hydrogeology; Metal concentrations; Metals; Natural water pollution; Natural waters; Organic carbon; Pollutants; Pollution; Polysaccharides; Retention; Size distribution; Soil Science & Conservation; Statistical analysis; Studies; Trace metals; Ultrafiltration; Water Quality/Water Pollution; Water treatment and pollution
• ISSN: 0049-6979; 1573-2932
• DOI: 10.1007/s11270-007-9504-z

Interdisciplinary studies on aquatic environments and cross-validation of laboratory vs. field results will likely increase the need for simultaneous use of large- and small-scale ultrafiltration systems. In this study, a comparison of two ultrafiltration systems differing in scale (PrepScale and PelliconXL, Millipore; membrane areas 0.54 m 2 and 0.005 m 2 , respectively), was made for the cut-offs 3 and 300 kDa. Large systems are useful for their high permeate throughput, while small systems are necessary when the amount of sample is limited. The ability of PrepScale and PelliconXL systems to provide comparable results for organic carbon fractionation was studied for polysaccharide solutions and natural freshwaters. In the latter, the colloidal proportions of different trace metals (V, Cr, Mn, Co, Ni, Cu, Sb, and U) were also determined. Although the colloidal proportions obtained with PelliconXL 3 kDa were sometimes slightly higher than with PrepScale 3 kDa (principally for DOC and U in natural waters), Mann–Whitney statistical test showed no significant difference in the overall fractionation properties of the two systems. Our observations show that reaching high concentration factors lead to a strong modification of colloids size distribution in the range 50–2,000 nm and thus low concentration factors are preferable to preserve the colloid integrity.