starts where we left last time remember
we were talking
we here
ocean and particularly nitrogen oxides
and the smog as we see here you and
usually we see those above the skies of
the big cities during the wintertime
sometimes in the summertime - and the
main constituent there is the oxides of
nitrogen nitrogen oxide actually you
know comes from the engines automobile
engines mostly and as soon as it comes
out from the exhaust pipe it is
converted to the no.2 and actually that
no.2 is the one which gives that color
to this month smug is the combination of
the word derived from the smoke and fog
those combinations I guess in England
they derived the word smug and in
addition to the nitrogen oxide there are
other pollutants actually in this smog
and as I said last time this simply
takes place when you have special
weather conditions and it is usually as
follow simply as you go about the earth
the temperature decreases normally right
but sometimes some weather conditions at
somewhere around here where the smug
simply forms the temperature below is
actually lower than the temperature
above and that polluted air that smug
actually trapped in there and stays for
a long time it can't really go up
because of that inversion it's called
inversion which is not normal conditions
actually for the weather but it
sometimes happens and we see those smug
as a matter of fact okay now the
greenhouse effect again we have to
remember that the earth simply there are
three things
that makes the life possible on the
earth one is the energy coming from the
Sun and the second one is the atmosphere
and the third one is the water right
energy atmosphere and water now you have
to simply imagine that as the heat
absorbed coming from the Sun in the form
of radiations different form of
radiations but some of the energy is
also dissipated from the earth to the
space again and to keep the proper
temperatures on the Earth's surface
actually right
then there has to be an equilibrium
between this energy given off by the
earth and the energy taken from the Sun
again and if this temperature simply
changes that means the global
temperature changes then we see a lot of
changes in the climate and we see
changes in the current of the oceans
actually and the winds and things like
that actually the climate changes as a
matter of fact now but what we have
again as to keep the temperature of the
surface particularly at night earth
surface the heat that scattered from the
surface in the form of infrared
radiations into the sky actually is
trapped by certain gases in the
atmosphere and these gases are called
greenhouse gases greenhouse gases what
what I mean by trapping that means these
gases particularly absorbs the infrared
radiations that energy and then
converted to the kinetic energy and that
for the temperature of the earth is sort
of maintained at a certain value
particularly at night as a matter of
fact and these gases that traps the
heat actually in the atmosphere are the
first one is the water vapor water vapor
as the first one second one is the
carbon dioxide and the third one is
methane actually so these three gases
are known as the greenhouse gases and
they are absorbing the scattered
infrared radiation from the surface of
the word earth and keeps that keeps the
temperature there sort of maintain
certain values and that way there is a
balance again right now the amount of
these greenhouse gases in the atmosphere
should be certain amounts so that the
temperature of the earth will be about
the same or dependent on the climates in
fact you know will change but will stay
about the same as a matter of fact now
or average global temperature will be
about the same now if you increase the
somehow disturb this there is a balanced
natural balance actually about the
amount of these greenhouse gases that
present in the atmosphere and stays
about the same but human activities in
fact due to human activities these
greenhouse gases the amount of
greenhouse gases in the atmosphere
changes and when you change those
increase in those amount actually means
that more energy trapped on the surface
of the earth so the global temperature
increases and we don't want that because
it affects the climate if I've acted
climate now let's see how the change of
the temperature global temperature in
the last since 1960 actually you see
again it's about 330 ppm this is the
carbon dioxide actually the greenhouse
gases that is introduced by human
activities to the atmosphere the first
one is the carbon dioxide right because
carbon dioxide comes out from the
engines comes out from the
power plants and a huge amount of carbon
dioxide is released into the atmosphere
every year you know billions of tons 10
to the 21 billion of tons carbon dioxide
is released and that increased disturbed
the balance of the carbon dioxide
present in the atmosphere and increases
the amount of the carbon dioxide as you
see here it increased since 1962 300
from 320 to about 400 400 and again the
studies have shown that the carbon
dioxide amount in the atmosphere did not
change almost in the last 10,000 years
until about 3000 years 300 years ago
where the Industrial Revolution started
again now during that time the carbon
dioxide level was you know almost the
same maintain about the same but started
from the 300 years actually the carbon
dioxide level increased in this 300
years increased about 30% right 30
percent and that increase in a 30
percent increase increased the global
temperature between 0.3 to 0.5 degrees
centigrade right and they say and that's
really affected a lot of changes in the
climate as a matter of fact and if we do
not take any precautions to control the
amount of carbon dioxide released in the
atmosphere in the years of 2100 or 2050
actually they say that the carbon
dioxide level will be so high that the
global temperature increase will be
about you know 1 to 3 degrees centigrade
but those global temperature average
increase wanted a degree centigrade is
it is really big change and that because
change is a lot of balances natural
balances that took place for years and
years on the earth as a matter of fact
and climate changes that means that the
some places
it drains more and some places it rains
less and some places we have winds and
gusts and things more than we used to in
some places less as a matter of fact but
remember again increase in the amount
the global temperature the average
global temperature dissolves the ice on
the north and south pole and that pull
changed the level of the Seas again
oceans and that will have a lot of other
effects on the human beings or live in a
game particularly those people live in
close to the sea Shores as a matter of
fact so it is very important to control
the carbon dioxide in the air because
the global temperature increases again
this is water is again is the major
absorber of the radiations this is a
carbon the greenhouse gases locations at
time of the year says level vary by
location at time of the year that means
the amount of water for example as I
said in the desert the temperature
between the night and the day is so high
why because it is so dry there there is
no greenhouse gases above the desert
which will absorb the radiations at
night and keep the temperature sort of
you know certain values but it be heat
scattered from the surface in fact from
the desert dissipates into the space and
the temperature drops drastically at
night as a matter of fact carbon dioxide
levels from human use of fossil fuels we
talked about this have increased
dramatically over last century and as I
said increase about in the last 300
years increase about 30% as a matter of
fact and this is likely chosen and
unnaturally increase in the atmospheric
temperature definitely there is a
relationship between the increase in the
carbon dioxide in atmosphere and the
global temperature increase now let's
look at the water again on
remember again water is another things
that makes the living possible on the
earth in addition to the energy that
come in from the Sun and the atmosphere
and this shows how the water cycle is
taking place and again this gives you
again the some knowledge about the water
around the world on the earth this is
the world oceans ninety seven point two
percent of all water on Earth is in the
oceans so that's really great very large
amount the waste ocean contains many
important compounds and minerals and
these are actually what we have in the
oceans but again however it says the
ocean is only the commercial source for
sodium chloride bromine and magnesium
soles so that simply means from the
ocean water we obtain sodium chloride
and we obtain bromine and also the
source of magnesium in a day even though
we have a lot of other things in the
oceans and these are the selling it
salinities and the concentrations in
molar concentrations and sea water
oceans water now fresh water all fresh
water is only about it says point six
percent of the water on the planet
that's very small amount and this is for
the u.s. uses of fresh water almost
forty one percent of the fresh water
goes into agriculture use in agriculture
thirty-nine percent is hydroelectric
powers and six percent in industry and
six percent in household needs and
drinking water is only one percent but
that is important because there are a
lot of places on the earth that they
have problem getting enough drinking
waters as a matter of fact particularly
because we
pollute the water human activities on
the earth pollute the water they have to
be prevented - and some says that about
fifty years or a hundred years there
will be very big problem in getting
enough water actually drinking water as
a matter of fact fresh water now use off
the water adds dissolved materials
including human waste in fact it will
become increasingly expensive to
guarantee our water supply because we
pollute the water all the Switch in fact
or other things from the chemical
industry goes into the water and makes
the fresh water undrinkable actually so
that will be definitely a problem we
have to consider that now the
groundwater is again fresh water under
the soil in aquifers this is I guess the
civil engineers know this word these are
the deposits of the water underground
and sometimes they are very very old
they stay there for years and years
unless we pump them out and those are in
fact it takes again years to fill out
those aquifers in Cyprus for example
they used to have very rich aquifers in
guzelyurt and that was all used up now
they don't have enough water groundwater
in the Cyprus remember we gave them
water through the sea under the sea what
pipelines as a matter of fact so when
use these sources of water are not
readily regenerated it takes a long time
for water to penetrate the rock layers
which create an aqua fire this is what
again.we says about the aquifers these
are simply the deposits of fresh water
underground not all ground water is
portable
this means drinkable and due to ions in
the rock formation some will contain
poisons like arsenic
high levels actually so again we have to
be careful what we have under our
aquifers if we use and drinking that
water there because the water remember
is a polar solvent and it will dissolve
salts in it and those souls may be toxic
like salts of the arsenic and we have to
be careful about that too now dissolved
oxygen in water is very important and
the amount of dissolved oxygen present
in the water indicates the quality of
the water again now it says the amount
of o2 in water is an important indicator
of the water quality and the value sets
in fact for good water would be like 9
ppm oxygen dissolved in water now for
the fish to be able to live in the water
the oxygen dissolved should be minimum
of 5 ppm right 5 ppm so if it is below
that that means the fish will not be
able to live in fact if there is not
enough oxygen dissolved in the water no
other living organisms will be present
there - now let's see the story about
this again oxygen dissolved and the
bacteria when aerobic bacteria act on
biodegradable degradable matter they use
oxygen actually these bio degradable
matter these are organic waste actually
goes into the water and if you have
organic wastes in the water than these
arabic aerobic bacteria that means which
uses oxygen air to work on these
biodegradable matter organic matters and
it decreases the amount of oxygen in the
water dissolved oxygens so that means if
you have organic wastes in the water
that will cause to decrease the
dissolved oxygen in that water that
means in that water there will be no
life the present there right so those
bacteria uses the oxygen work on this
biotech
edible manners as a matter of fact
excessive amount of biodegradable matter
can result in inability of normal animal
life to exist in the water again no fish
no other things if the level of the
dissolved oxygen goes below below
certain value as a matter of fact now it
can also lead to an ironic oxidation
conditions which give off bad orders now
this is very interesting as a matter of
fact now if you have enough oxygen
dissolved in the water and you have
those organic waste in the water these
aerobic bacteria will work on those and
then use the oxygen and then degrade
actually all those organic wastes right
but if there is no oxygen in the water
if all oxygens are used up by these
bacteria then the ni aerobic bacteria
comes in and then it starts working on
those organic based again right and
these ni aerobic bacteria when they work
on their these biodegradable organic
matters again the products are different
one of the products for example is the
hydrogen sulfide ammonia and methane as
a matter of fact in when the ni aerobic
bacteria works on the organic waste as a
matter of fact and that's what they give
that order that the order comes from
that particularly the hydrogen sulfide
comes out from there now if you have
simply excessive plant nutrients can
lead to eutrophication or excessive that
plant matter in water this is again this
simply means this now particularly that
the three elements are essential for the
plant's food and that is one is the
potassium the other one is the
phosphorus and the other one is the
nitrogen phosphorus nitrogen and
potassium the comp
of those actually all fertilizers
contains these either nitrogen potassium
or phosphorus as a matter of fact so if
you have simply plans in the water and
you have the simply a lot of green
plants in the water and they will create
organic waste because some of those
plants will die and then will stay in
the water they will be organic waste
now the aerobic bacteria starts working
on those organic wastes and use up the
oxygen dissolved in the water and that
also decreases the oxygen level and that
means makes it impossible for the
organisms fish and other things that
live in that water so we don't want a
lot of plants growing in the water now
why those plants grow in the water
because when we throw in their compounds
containing phosphorus compounds
containing potassium or nitrogen
compounds particularly the detergents
which contains phosphorus a lot of
phosphorus if you just take those
detergents and you know the washing
water goes into the lakes and things and
then you have a lot of plants aren't
growing and when those a lot of plants
are growing that means it's not more any
more healthy that water for the living
organism because the oxygen dissolved
decreases drastically as a matter of
fact now let's look at the water
purification now water purification we
can't use the ocean water there's so
much water in the oceans as I said
ninety seven percent something like off
the water present on earth are in oceans
but these ocean waters are salty they
contains a lot of souls and they are
called saline water means a lot of salts
there particularly we have the sodium
chloride again we know in seawater but
how can we purify the seawater or other
waters so that we can use them
make them healthy and drinkable as a
matter of fact there are two ways of
purifications particularly the seawater
one is the distillation right you take
the water and then you boil it and
distill it and that's again very very
expensive and it's not very easy because
there's so many so much salt dissolved
in the seawater as you boil out that a
lot of salt will deposit at the bottom
and plus it will require energy to boil
those it's not very economic as a matter
of fact now the second one is by reverse
osmosis process reverse osmosis and this
is the one which which is really used a
lot particularly in Saudi Arabia even
though it's still expensive but not as
expensive as distillation as a matter of
fact what is reverse osmosis means okay
now remember that if you have water very
thin let's say it's considered this is a
very thin glass tubing like this and I
put here a membrane this is called semi
permeable membrane here and then let's
say that we put here pude water h2o pure
and here we put let's say we have simply
let's say 0.2 molar sodium chloride
solutions like this now assume that
these are capillary very thin very very
thin now what will really happen if I
have a system like this this is a
semi permeable membrane and that
membrane allows the passage of water
solvent from one side to the other side
but do not allow the passage of the ions
or the salt ions again right so as soon
as I put the water pure water here and
the salty water here and what would
really happen this level will go up like
this let's upon an age and this level
will go down right same amount simply
this will go down and this will go up
like this and the difference here is
called actually the osmotic osmotic
pressure right yours much pressure why
this is a game because of the entropy
effect as a matter of fact what really
happens is that when this water simply I
have two system here water which have no
ions and I have the water here has you
know 0.2 molar ions so what the nation
will try to do try to equalize the
concentrations of these two solutions as
a matter of fact even though this is not
as solutions but since there will be no
way to equalize the concentrations
bypassing the sodium chloride from this
permeable membrane to this side what
happens how the concentrations can be
made close if I dilute this simply
solutions and if I increase the
concentration on this side right now
dilution of this solution means I have
to add more water to this and that water
actually passes through this membrane
and then comes over here and that level
goes up like this and that because that
level goes down now when the pressure
from this side and this side becomes
equal then they stay and that difference
again difference in the pressure between
these two are called osmotic pressure as
I told you and dependent on the
concentration the osmotic pressure will
increase or decrease again
now let's assume that instead of leaving
it this alone I have the ocean water in
this side and then pure water here
instead of letting that alone I simply
put here a pressure apply here a
pressure right here I simply apply a
pressure and then push it down if I push
it down what I what happens the
automatic process is reversed right when
I push it down here it will come down
like this depending on out what pressure
I apply air it should be definitely
greater than the automatic pressure
right and then then the water pure water
on this side will pass through the
semipermeable membrane on that side and
then the pure water amount and this
column here will increase that's again
the principle of reverse osmosis to
desalinate the ocean water ocean water
the system is similar to this put the
ocean water and then you put the
pressure on it big pressure and put a
permeable membrane you have to have that
membrane and keep all the salt all the
ions on this side and get the fresh
water and you can use that fresh water
as a matter of fact so that is the
reverse osmosis and you see again here
you pull fill out all these with the
water from the ocean and these are all
semipermeable membrane you apply a
pressure there when you apply a pressure
and pure water comes out from these
tubes and you connect collected from the
other side and use the water again right
so this is again if pressure is applied
the water can be forced through a
membrane in the opposite direction
concentrating the pure water this is
what it simply I try to show you here
that's exactly what how we describe it
okay now uh water purification for the
municipal water that's the purification
of the sea water actually it make the
sea
water possible make it drinkable water
actually and we should also purify the
municipal water before we throw them
into the waste right and that is also
important too and steps to purifying
water forum Universal municipal supply
what is municipal yes what is the
Turkish word for municipal bill idea yes
that's the Bolivia actually now we add
calcium oxide and that makes the
solution basic and then we add aluminium
sulfate and that in the basic solution
precipitate aluminium hydroxide but as
it precipitated it also brings down or
other even bacteria and small particles
with it added to removal of the very
small particles and then water is
aerated to increase the amount of
dissolved water you see again this is
the aeration right there water and this
is we take the tanks and then keep it
there for a while and filter it before
we go here and add the calcium oxide
aluminum sulfate there and it
precipitates and we take from there
arrow fired and then water is aerated
again to increase the dissolve oxygen
oxidation organic impurities the ozone
or chlorine is used to disinfect the
water again remember usually we use the
chlorine we add chlorine gas to the
drinking water to kill the bacteria or
other germs again viruses and parasites
and things like that but in the last few
years they find out that the chlorine is
not also so good for the drinking water
and when you have the chlorine it
generates other species and it causes
cancer those products as a matter of
fact therefore if you're going to use
the chlorine we have to simply keep the
amount of dissolved chlorine in the
sewer in water very very low actually
and what is the alternative
the alternative is owes on but ozone
also have some problems with it too
we have to be very careful about to use
the ozone to disinfect the drink
drinking waters again now this this
shows again how we can probably solve
the drinking water problem on the earth
particularly in the places where the
people do not have an excess to good
water enough drinking water and this is
called the live stroll I see there again
and it looks like and all that big
things and what we have here we have the
filters and then we have the iodine's
actually the two kinds of filters we
have the iodine's
and then we have the charcoal actually
varied powder of graphite as a matter of
fact called charcoal and let's look at
here as one sucks water through the
straw from there actually this is really
you know terrible water but the water
comes out in your mouth is drinkable
becomes drinkable what are the processes
that it goes through now filters remove
most of the sediment and bacteria this
filters here remove some sediments and
bacteria iodine right here in fact beads
then kill viruses see again they killed
the viruses and bacteria that's very
important and then the charcoal here
removes the iodine smell and most
remaining parasites there and also bad
orders so a very simple system but
allows you to drink the waste water
right
no that's possible but it's they say
it's still very expensive to give it to
people
Africa or somewhere else it cost a lot
but it may be cheaper in the future okay
now the next is the green chemistry this
is a game the earth can largely be
considered as a closed system right
which can exchange energy with the rest
of the universe energy state we get the
energy from the Sun and some of the
energy is released to the space actually
but keeps inside the mask whatever mass
we have that's on the earth here so for
the humanity to live on the earth
happily actually we need to keep our
process in balance with the earth
natural processes so there is always a
natural ecological balance on the earth
actually now if we disturb this
ecological balance then we will have
problems actually all living organisms
will have problems living on the earth
as a matter of fact and for that we have
to take some precautions for that to
keep that balance with the earth natural
processes now it says this is the basis
for green chemistry actually the green
chemistry which simply considers keeping
this biologic at the ecological balances
of the earth natural balances of the
processes taking place on the earth now
definitions of the green chemistry is
given again as follow green chemistry is
an initiative that promotes the design
and applications of the chemical
products and the processes that are
compatible with human health and that
pre preserve the environment now this is
important so when we simply carry out
chemical reactions or chemical processes
on the earth it says we have to simply
consider this balance and make the aim
should be human health and preserve the
environment
preserve their mind again you see most
of the pollutants are produced by the
chemical industry but the removal of
those pollutants or find the remedy for
the environmental problems is also a
knowledge of chemistry requires a
knowledge of chemistry - chemistry is
very very important in this respect now
these are the principles of the green
chemistry
the first one is says prevention it is
better to prevent waste then to clean it
up after it has been created that means
we don't really have to create waste you
know it's not simply so practical after
we create ways to clean that waste but
rather than not produce that waste
prevent that waste formation happening
before actually now this is Atem economy
this is for the chemical reactions
actually it says methods to make the
chemical compounds should be designed to
maximize the incorporations of all
starburns atoms into the final product
what this simply means that when we
start with the reactants in a chemical
reactions if somehow all the atoms that
present in chemical reactants appears in
the chemical product there is no other
side product that means it is the best
economy right in terms of number of
atoms number of substance actually and
that's called the atomic action economy
atom economy that means all of the atoms
that enters any chemical reaction we
desire to have them all in the product
that we would like to obtain not the
side product or the other things that
comes out from the reaction that's what
it means now the third is less hazardous
chemical synthesis wherever practical
synthetic matters should be designed to
use and generate substances that possess
little or no toxicity to human human
health and the environment you see again
human health and environment
to protect is important one of the aim
of the green chemistry actually now the
fourth is design of safer chemicals
chemical products should be designed to
minimize toxicity and yet maintain their
desired function particularly the
toxicity is very very important we try
to use non-toxic chemicals in our
chemical reactions in fact as much as
possible now safer solvents in and
auxiliaries the use of the auxilary
substances should be eliminated wherever
possible and if used should be as
non-toxic as possible now sometimes we
want we have to use the organic solvents
which are volatile organic solvents they
are not good at all so instead of using
them in fact we can use other solvents
as we will see for example supercritical
carbon dioxide carbon is a very good
solvent for a lot of chemical reactions
and very safe - as a matter of fact so
the sixth one is designed for the energy
efficiency energy requirement should be
reorganized for their environmental
economic impacts and should be minimized
for example carry out reactions at room
temperature and pressures what this
simply says we have to be very very
conservative in using the energy sources
try to use minimal amount of energy
right if a reaction for example is
taking place at high temperatures we
have to use energy to increase the
temperature to there or at high
pressures also cost energy so we try to
design our reaction such that room
temperature and normal pressure one
atmosphere pressure will be enough for
the reaction to take place actually now
the seventh one is use of the Renewable
renewable feedstocks a raw material
should be renewable whenever technically
and economically practical this simply
says that the reactants that we use
our chemical reactions should be
renewable type reactants renewable type
reactors now eight reduction of the
derivatives this is unnecessary
derivatives a ssin should be minimized
or avoided if possible to save reagents
and waste this is again simply if I have
site products or intermediate products
and that kind of things we try to reduce
those as a matter of fact and that is
the reductions of the derivatives
anything that we don't want should not
come out in our chemical reactions we
have to design them accordingly now nine
we have to use the catalyzed what
happens when you use a catalyzed than
the time for the reaction to take place
decrease and that simply save the energy
as a matter of fact catalytic reagents
improve yields within a given time that
means in a shorter time we get a larger
yield and with less energy and are
therefore preferred again the energy
conservation they're now nine design for
degradation chemical products should be
designed so that the end of their
functions they break down into innocuous
in Norco shoes products and do not
persist in the environment this word
means not harmful not harmful so that
simply means that we try to produce
degradable products that means after we
use it for a certain time they will
simply decompose and go into the
environment without any side effects and
eleven real-time analysis for the
pollution prevention analytical methods
should be developed to allow for
real-time monitoring and control prior
to the formations of hazardous
substances this is again similar to like
not having the waste
rather than cleaning and up after we
produce it and in this case it says that
if we can control our chemical reactions
as it goes monitor the reactions as soon
as we realize that
some unwanted things are happening we
should just prevent it right there at
that time now the last one is inherently
safer chemistry for accident prevention
this is certainly good things in fact
reagents and solvent use in a chemical
process should be chosen to minimize the
potential for chemical accidents for
chemical accidents so these are the
principles of the green chemistry here
are three examples for example the
preparation of styrene styrene is a
monomer for polystyrene it's a polymer
actually and all these styrofoam's
are made from these polystyrene and a
huge amount of that polystyrene is
produced and to make the polar styrene
we meet the monomer styrene and here we
see the productions of styrene in one
step actually this is a green chemistry
step in a previous step which is present
in the book it uses three different
steps instead of three steps in one step
we produce the styrene and this is again
what the green chemistry does as a
matter of fact now replacing
chlorofluorocarbon solvents with liquid
or supercritical carbon dioxide remember
the supercritical carbon dioxide above
the critical temperature and it is
between the gas and the liquid sort of
and we can use those carbon dioxide to
breathe a lot of things actually
for example the caffeine free coffee is
produced by using this supercritical
carbon dioxide yes Cafe cafe in free
coffee yes now this is another example
hydroquinone production by a new method
that recycles byproducts again we have
this is one step this is the second step
but the nice things with this process is
here we have a side product here we have
another side product in two steps these
two side brought products can be
combined to obtain the
reactance again right so that's what the
energy-saving and atom economy would
whatever their say we try to reduce the
side products as much as possible again
okay like Oh time is over