Environmental Engineering Reference
In-Depth Information
COLLOIDS OR
MACROMOLECULES
SOLUTES
-10
PARTICLES
log(size/m)
-9
-8
-7
-6
-5
1 A
1 nm
1
µ
m
0.45
µ
m
Cellular debris
Polysaccharides
Amino acids
Peptides
Peptidoglycans
Proteins
Fulvics
Humics
Humic aggregates
Viruses Bacteria
Organic compounds adsorbed
on inorganic particles
Clays (aluminosilicates)
Fe oxyhydroxides
Mn oxides
Metal sultides
Carbonates, phosphates
Algae
(b)
'Simple'
hydrated
ions
(e.g. OH
-
, Cl
-
,
SO
-
, HS
-
,
Na
+
, Ca
2+
,
Mg
2+
, Cu
2+
,
etc.)
4
Amorphous SiO
2
Ultrafiltration
Electron microscopy
Atomic force microscopy
Flow-FFF
FCS
Filtration
Confocal microscopy
Optical microscopy
Sedimentation-FFF
Light scattering
X-Ray, neutron scattering
X-Ray absorption
LIBD
(a)
(c)
Figure 4.1
(a) Schematic representation, by size distributions, of the major environmental
colloidal and particulate components; (b) typical example of natural colloids and aggregates
(Rhine River), scale bar corresponds to 1
m and (c) natural heteroaggregate of colloids and
particles from Lake Bret, Switzerland, as shown by transmission electron microscopy, scale
bar corresponds to 250 nm. ((a) Lead, J. R. and K. J. Wilkinson (2006) Aquatic colloids and
nanoparticles: current knowledge and future trends,
Environmental Chemistry
,
3
, 159-71.
Reproduced with permission from CSIRO publishing, http://www.publish.csiro.au/journals/
ec. (c) Reprinted with permission from J. Buffl e, K.J. Wilkinson, S. Stoll, M. Filella, J. Zhang,
A generalized description of aquatic colloidal interactions: the three-colloidal component
approach,
Environmental Science & Technology
,
32
, 2887-99. Copyright 1998, American
Chemical Society.)
µ
Zimmermann-Timm, 2002). Hence, one of the ways to understand colloids is to
study them by classes of compounds of similar composition and properties. Figure
4.1a summarizes the different types of environmental colloids together with the
size range they cover and the analytical tools (see Chapter 6 for detailed discussion)
that can be used to characterize them. Figures 4.1b and 4.1c show typical examples
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