Environmental Engineering Reference
In-Depth Information
4 . Maximize effi ciency : Designing of products,
processes, and systems to maximize mass,
energy, space, and time effi ciency.
5 . Output pulled versus input pushed : Products,
processes, and systems should be “output
pulled” rather than “input pushed” through
the use of energy and materials.
6 . Conserve complexity : Embedded entropy
and complexity must be viewed as an invest-
ment when making design choices on recy-
cle, reuse, or benefi cial disposition.
7 . Durability rather than immortality : Design
goal
tems for performance in a commercial
“after life.”
12. Renewable rather than depleting : Material
and energy inputs should be renewable rather
than depleting.
5
Nanobiosynthesis
Nanobiosynthesis or biogenic production of
nanoparticles refers to the use of several species
of bacteria, plants, yeast, and fungi for production
of nanoparticles or to aid in the process. “Green”
synthesis particularly refers to use of plants for
production of nanoparticles. Nanobiosynthesis is
of great interest due to simplicity of procedures,
versatility, and environmental friendliness.
Besides, the biologically fabricated nanostruc-
tures offer substantially different properties such
as good adhesion, tribologically good properties,
and optical and electrical properties of high inter-
est in optoelectronics (Popescu et al. 2010 ). The
general biosynthesis of metal nanoparticles from
biological sources is depicted in Fig. 1 ( Li et al.
2007b ; Sharma et al. 2009 ; Prathna et al. 2010 ).
should
target
durability
than
immortality.
8 . Meet need, minimize excess : Design for
unnecessary capacity or capability should be
considered a fl awed design.
9 . Minimize material diversity : For promotion
of disassembly and value retention.
10. Integrate material and energy fl ows : Design
of products, processes, and systems should
include integration and interconnectivity
with available energy and material fl ows.
11. Design for commercial “after life” :
Designing of products, processes, and sys-
Bio-reductant bacteria, fungi, or plant parts + Metal ions
(May be enzyme/photochemical)
Reactant conc., pH, Kinetics,
mixing ratio
solution chemistry, interaction time
Metal nanoparticles in solution
Purification and recovery
UV visible analysis (SPR)
Nanoparticle powder
SEM, TEM, DLS, XRD
Physicochemical characterization
Does not meet shape, size,
distribution criteria
Meet shape, size, and size
size distribution criteria
Modify process variables
Biofunctionalization
End use
Fig. 1
Generalized fl ow chart for nanobiosynthesis (Prathna et al. 2010 )
 
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