Analysis of Colloidal Phases in Urban Stormwater Runoff
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- 作者：Hé ; lè ; ne Grout ; Mark R. Wiesner ; and Jean-Yves Bottero
- 刊名：Environmental Science & Technology
- 出版年：1999
- 出版时间：March 15, 1999
- 年：1999
- 卷：33
- 期：6
- 页码：831 - 839
- 全文大小：278K
- 年卷期：v.33,no.6(March 15, 1999)
- ISSN：1520-5851
文摘
The composition and morphology of colloidal materialsentering an urban waterway (Brays Bayou, Houston, U.S.A.)during a storm event was investigated. Analyses oforganic carbon, Si, Al, Fe, Cr, Cu, Mn, Zn, Ca, Mg, and Bawere performed on the fraction of materials passingthrough a 0.45 
m filter. This fraction, traditionally definedas "dissolved", was further fractionated by ultracentrifugation into colloidal and dissolved fractions. Colloids,operationally defined by this procedure, accounted for17% of the carbon, 32% of the silica, 79% of the Al, 85%of the Fe, 52% of the Cr, 43% of the Mn, and 29% of the Znpresent in filtrates when averaged over the storm event.However, the composition of colloidal material was observedto change over time. For example, colloids werepredominantly composed of silica during periods of dryweather flow and at the maximum of the stormwater flow,while carbon dominated the colloidal fraction at thebeginning and declining stages of the storm event. Thesechanges in colloidal composition were accompanied bychanges in colloidal morphologies, varying from organicaggregates to diffuse gel-like structures rich in Si, Al, andFe. The colloidal phase largely determined the variabilityof elements in the 0.45 m filtrate.
m filter. This fraction, traditionally definedas "dissolved", was further fractionated by ultracentrifugation into colloidal and dissolved fractions. Colloids,operationally defined by this procedure, accounted for17% of the carbon, 32% of the silica, 79% of the Al, 85%of the Fe, 52% of the Cr, 43% of the Mn, and 29% of the Znpresent in filtrates when averaged over the storm event.However, the composition of colloidal material was observedto change over time. For example, colloids werepredominantly composed of silica during periods of dryweather flow and at the maximum of the stormwater flow,while carbon dominated the colloidal fraction at thebeginning and declining stages of the storm event. Thesechanges in colloidal composition were accompanied bychanges in colloidal morphologies, varying from organicaggregates to diffuse gel-like structures rich in Si, Al, andFe. The colloidal phase largely determined the variabilityof elements in the 0.45 m filtrate.