▶ Your Answer :
The lecturer asserts that the mechanisms addressed
in the reading passage to get rid of harmful substances in the coal have significant
drawbacks. This counters the reading passage’s claim that gasfication, a form
of static electricity, and fabric filters can reduce the air pollution resulted
from using coal.
First, the lecturer mentions that transforming
coal into gas is not environmental friendly. This process requires burning a
large amount of fossil fuels, which pollutes air. The disadvantage of emitting
harmful chemical from burning fossil fuels outweighs those of its counterpart. Moreover,
removing all the impurities from the coal needs a huge amount of water as well.
This water usage leads another environmental destruction. This cast doubts on
the reading passage’s claim that gasification that changes coal into gas and
extracts all the toxic chemicals is eco-friendly and a innovative progress in
terms of reducing detrimental effect from using coal.
Second, the lecturer argues that a method
of utilizing electricity to pull out the pollutants generated by coal out of
air is not viable. The major problem of this method is that it can only extract
ash particles not green-house gases such as carbon dioxide emission which
contributes to the global warming. Although the reading passages mentions that an
electronic charge can pull dust particles from the coal smoke and holds them in
a collection plate, it is no use if other toxic substances stay in the air. This
refutes the reading passage’s idea that we can minimize the bad environmental influence
of using coal through extracting the pollutants from the air by handling a form
of static electricity.
Lastly, the lecturer says that an option of
fabric filter requires a lot of effort come from maintenance. Because the
fabric only lasts in a short period, it needs to be changed regularly. So it is
not cost-effective, although the reading passage asserts that the textile
filter removes over 99 percent of emission, which makes it an effective
technique. Also, operating a large band mandates a tremendous energy use. This
rejects the reading passage’s claim that the mechanism is totally feasible that
fabric filters installed in vents of coal power stations function as collecting
all the waste emitted from coal. |