Influence of ionic strength and pH on the limitation of latex microsphere deposition sites on iron-oxide coated sand by humic acid

Autor(en)

Thilo Hofmann, Frank von der Kammer, Xingyao Yang, Ray Flynn

Abstrakt

This study, for the first time, investigates and quantifies the influence of slight changes in solution pH and

ionic strength (IS) on colloidal microsphere deposition site coverage by Suwannee River Humic Acid

(SRHA) in a column matrix packed with saturated iron-oxide coated sand.

Triple pulse experimental (TPE) results show adsorbed SRHA enhances microsphere mobility more at

higher pH and lower IS and covers more sites than at higher IS and lower pH. Random sequential

adsorption (RSA) modelling of experimental data suggests 1 mg of adsorbed SRHA occupied

9.28 0.03 109 sites at pH7.6 and IS of 1.6 mMol but covered 2.75 0.2 109 sites at pH6.3 and IS of

20 mMol. Experimental responses are suspected to arise from molecular conformation changes whereby

SRHA extends more at higher pH and lower ionic strength but is more compact at lower pH and higher IS.

Results suggest effects of pH and IS on regulating SRHA conformation were additive.

Organisation(en)

Externe Organisation(en)

Queen's University Belfast

Journal

Environmental Pollution

Band

159

Seiten

1896-1904

Anzahl der Seiten

9

ISSN

0269-7491

Publikationsdatum

2011

Peer-reviewed

Ja

ÖFOS 2012

105303 Hydrogeologie, 104023 Umweltchemie, 105105 Geochemie, 105904 Umweltforschung

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