Environmental Engineering Reference
In-Depth Information
3.5 Waste Remediation, Resource Recovery, Water Reuse
The term
and its underlying conceptual understanding represent the ultimate
example of resource-impact externalization. This results as much from disciplinary
and operational specialization as it does from practices on the ground, where indeed
reuse and recovery of urban wastewater in this particular case are common despite
of
'
waste
'
'
to
'
resource recovery
'
in past work (Scott et al.
2004a
,
b
; Drechsel et al.
2010
);
however, here we offer a targeted WEF Nexus view on water reuse and recycling.
The most common use of treated or untreated ef
cial bans on the practice. We have described the transition from waste
'
disposal
uent is agriculture in its broadest
sense, taken to include irrigation of livestock fodder (for reasons of perennial
ow,
nutrients and human health-risk aversion), as well as landscaping irrigation (in
many developed country contexts). Treatment and redistribution of reclaimed water
is highly energy intensive; for example, in Tucson, Arizona, planners and the public
are transitioning toward aquifer storage and recovery (itself not without energy
costs) due to
financial, infrastructural and public-acceptance challenges of dual
water-supply and
reclaimed water networks.
In the developing country context, agriculture and food production are central to
water reuse schemes, and will remain so in the future due to water, nutrient and
urban proximity imperatives. An excellent example is Bolivia, where UNU-FLO-
RES and the University of Arizona are keen to engage with local researchers and
stakeholders to systematically develop the technical guidelines and institutional
norms for safe and productive schemes for water reuse in agriculture.
'
purple-pipe
'
3.6 Renewable Energy: The Water-Land Nexus
Wastewater reuse has tremendous scope to advance the nexus through fostering
opportunities for multiple uses of water. But although a huge potential exists for
wastewater reuse in agriculture, its effectiveness as an adaptation pathway may
depend on critical aspects of local farming practices, market conditions, crop
varieties and implementation of cost-effective treatment measures that facilitate
wastewater reuse. For example a case study in India revealed that cultivating with
wastewater may be less
financially viable as compared to cultivating with well
water. Further, when health risks for humans and livestock and returns on crops
were considered, a number of interesting perspectives emerged (Kurian et al.
2013
).
First, because of better nutrient value of wastewater, farmers do not apply fertilizer.
Further, due to assured availability of wastewater, farmers can grow two crops. On
the other hand, farmers spend more on pesticides due to high incidence of pests
(white
y and jassid) under well irrigation. Wastewater reuse for agriculture is
sensitive to soil and crop type; in our study area only paddy could be grown using
domestic wastewater. Crops grown using wastewater sell for less in local markets
Search WWH ::
Custom Search