Design Your Own Underwater ROV - International Technology and ...

Credit: Texas Water Development Center
Photo 3. Water Treatment Plant
Water treatment plants process water through a series of settling and sedimentation, flocculation, and filtering steps. Chemicals are added
to eliminate bacteriological pathogens and meet health needs such as fluoridation to produce a high-quality water product.
disinfection, where chlorine can be used to remove odors
and taste. Water is then pumped to the households
for consumption.
Design Initiative for Students
A simple activity that can be conducted with students is
the filtration of water with the use of a homemade filter. To
build the filter, we need a one-liter plastic water bottle with
a lid that can serve as the housing for the filtration system
and an ordinary plastic straw that can serve as the spout.
The filtration system will consist of cotton batting, fine- and
large-grain gravel, fine- and large-grain sand, and a coffee
filter. A mug can be used to capture the filtered water.
To create this style of homemade water filter, students will
cut off the bottom of the one-liter water bottle and create
a hole in the lid of the bottle so that a straw may fit snugly.
The straw must sit halfway through the opening in the lid.
Once the straw is in place, add the cotton batting at the
bottom of the one-liter bottle and use it as lining for your
filtration system. Next, place a layer of fine-grain sand
followed by a layer of large-grain sand and follow the layers
of sand with a layer of fine-grain gravel and then larger-grain
gravel. Once the bottle is full with the sand and gravel layers,
top the filtration system with the coffee filter. The filter is
now complete. Students will then pour unfiltered water
through the coffee filter to work its way through the layers
of sediment to wick away the impurities in the water. The
cotton batting will catch particulates from the sediment and
act as a final buffer. Finally a few drops of chlorine can
be added in the filtered water to disinfect and finalize
the process.
Activities such as the one described above are easy
to correlate with the technological literacy standards
developed by the International Technology Education
Association (ITEA, 2000/2002/2007). See Table 2 for
correlations with ITEA’s standards.
Summary
Water quality is of concern to many. The substantial
value of water is confirmed by society’s need for water and
stability for all sectors, and it depends on access to reliable,
good quality water. A nation’s survival depends on and is
affected by water availability; therefore, water resources
14 • The Technology Teacher • April 2009