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BIBTEX RIS

Substâncias húmicas: sistema de fracionamento sequencial por ultrafiltração com base no tamanho molecular

2000; Brazilian Chemical Society; Volume: 23; Issue: 3 Linguagem: Inglês

10.1590/s0100-40422000000300020

ISSN

1678-7064

Autores

Júlio César Rocha, Luiz Fabrício Zara, André Henrique Rosa, Ézio Sargentini, P. Burba,

Tópico(s)

Water Quality Monitoring and Analysis

Resumo

MOLECULAR SIZE BASIS.A sequential system for fractionation by ultrafiltration (SSFU) equipped with advanced membranes filters (molecular size cut-off: 5, 10, 30, 50 and 100 kDalton) of the polyethersulfone type was developed for analytical fractionation of humic substances (HS) extracted from aquatic systems or soils.The device consists of five membrane filters (Sartocon® Micro) operated by a multi-channel peristaltic pump, enabling an easy handling, working in a closed system and with simple collection of the six obtained fractions (F 1 >100; F 2 : 100-50; F 3 : 50-30; F 4 :30-10; F 5 : 10-5 and F 6 <5 kDalton).Then, the HS sample (250 mL solution 1.0 mg/mL, pH 5.0 to 6.0) to be fractionated is pumped by pump through the series of membrane filters with a tangential flow of 85 mL/min, initial pressure 0.2 to 0.3 bar and permeation flux through the membranes of 0.8 to 1.4 mL/min.The overall time for fractionation and cleaning of the device is about 10 h and 25 mL of each fraction is obtained.

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