0
00:00:00,000 --> 00:00:29,000
♫

1
00:00:30,000 --> 00:00:31,000
Good morning.

2
00:00:31,000 --> 00:00:35,000
Today we are going to talk, on the one hand, about the pollutants that can affect water,

3
00:00:35,000 --> 00:00:41,000
the different types of pollutants there are, and, on the other hand, a type of pollution

4
00:00:41,000 --> 00:00:45,000
that affects surface waters, such as sewage.

5
00:00:45,000 --> 00:00:48,000
We start with the types of pollutants.

6
00:00:48,000 --> 00:00:52,000
We can make a division based on the characteristics of those pollutants and thus we can divide them

7
00:00:52,000 --> 00:00:56,000
into physical, chemical or biological pollutants.

8
00:00:56,000 --> 00:00:59,000
Within the physical pollutants, which do we have?

9
00:00:59,000 --> 00:01:01,000
We have, on the one hand, water.

10
00:01:01,000 --> 00:01:07,000
Water is going to be used as a coolant in the machines of the companies that generate

11
00:01:07,000 --> 00:01:09,000
any type of product.

12
00:01:09,000 --> 00:01:14,000
When we have an engine that is running, it is going to produce friction, it is going to produce

13
00:01:14,000 --> 00:01:20,000
heat due to that normal operation, and we have to cool it down if we don't want

14
00:01:20,000 --> 00:01:22,000
that engine to break down.

15
00:01:22,000 --> 00:01:24,000
How do we do it with water?

16
00:01:24,000 --> 00:01:30,000
The water that comes in from the surface water is cold water and comes out with a certain

17
00:01:30,000 --> 00:01:31,000
temperature.

18
00:01:31,000 --> 00:01:35,000
What can cause us to pour it directly into rivers or into the sea?

19
00:01:35,000 --> 00:01:42,000
On the one hand, it reduces the amount of dissolved oxygen because hot water contains

20
00:01:42,000 --> 00:01:45,000
less dissolved oxygen than cold water.

21
00:01:45,000 --> 00:01:48,000
What causes this, that the amount of dissolved oxygen is reduced?

22
00:01:48,000 --> 00:01:53,000
On the one hand, certain species are extinguished with certain temperature limits.

23
00:01:53,000 --> 00:02:00,000
If a fish has to lay its eggs at 10 or 15 degrees, if suddenly the water is 20 or 25,

24
00:02:00,000 --> 00:02:06,000
it will not be able to lay its eggs, it will even get sick and die.

25
00:02:06,000 --> 00:02:12,000
This can also cause other species to appear, which can be invasive species that are from

26
00:02:12,000 --> 00:02:16,000
other places, but it is good that they are adapted to that temperature range.

27
00:02:16,000 --> 00:02:21,000
Then certain species that should not be there begin to proliferate.

28
00:02:21,000 --> 00:02:27,000
Growth cycles can also vary, or that those animals, those plants, become abnormally

29
00:02:27,000 --> 00:02:35,000
small or abnormally large, with certain consequences that can have, that is, that suddenly

30
00:02:35,000 --> 00:02:40,000
they become super predators instead of predators and that they eat everything that appears out there.

31
00:02:40,000 --> 00:02:47,000
An abnormal reproduction, for example, salmonids, trout, salmon, when they change

32
00:02:47,000 --> 00:02:54,000
the temperature of the water, their reproduction is very affected, because they are fish that

33
00:02:54,000 --> 00:02:58,000
are very sensitive to different temperature variations.

34
00:02:58,000 --> 00:03:04,000
Radioactive particles can also appear, generally derived from nuclear power plants.

35
00:03:04,000 --> 00:03:10,000
Also hospitals, for example, hospital waste, usually have radioactive particles, because

36
00:03:10,000 --> 00:03:17,000
if they see us, they are going to do a x-ray, those x-rays are deriving from some place

37
00:03:17,000 --> 00:03:24,000
that ends up being water and can end up being incorporated into the water that is released into the river,

38
00:03:24,000 --> 00:03:26,000
that is released into the sea.

39
00:03:26,000 --> 00:03:33,000
Also a natural radiation derived from rocks, such as plutonium, which emit a series of

40
00:03:33,000 --> 00:03:34,000
radioactive particles.

41
00:03:34,000 --> 00:03:36,000
What effects do they have?

42
00:03:36,000 --> 00:03:42,000
They can accumulate in mud, that is, those radioactive particles from the water pass to the mud,

43
00:03:42,000 --> 00:03:49,000
and with the consequences that this entails, they can end up in organisms and generate mutations.

44
00:03:49,000 --> 00:03:52,000
Inhalation by radon is also very important.

45
00:03:52,000 --> 00:03:59,000
Radon appears mainly naturally in plutonic rocks and it is convenient in houses that are

46
00:03:59,000 --> 00:04:03,000
located in areas where there are this type of rocks, for example in the Sierra de Madrid

47
00:04:03,000 --> 00:04:08,000
there is a lot, or in other types of mountainous systems that are made of granite, it is convenient

48
00:04:08,000 --> 00:04:13,000
to ventilate the houses a lot because radon accumulates in the houses, it can end up in the water

49
00:04:13,000 --> 00:04:17,000
and we can end up ingesting them and it gives lung cancer problems.

50
00:04:17,000 --> 00:04:23,000
Solids in suspension, well, from the residual waters, the erosion of the soil, infiltrations

51
00:04:23,000 --> 00:04:29,000
cause an increase in turbidity, which implies an increase in turbidity, a decrease in photosynthesis.

52
00:04:29,000 --> 00:04:34,000
If the water is turbid, all the organisms that are below that do the photosynthesis

53
00:04:34,000 --> 00:04:35,000
will not be able to do it.

54
00:04:35,000 --> 00:04:42,000
With this, there is also an alteration of the trophic chains, because we eliminate the primary producers.

55
00:04:42,000 --> 00:04:47,000
It can also cause mobility and breathing difficulties, let's remember that there are many organisms

56
00:04:47,000 --> 00:04:54,000
that live underwater and that move and breathe underwater, so if the water is full of

57
00:04:54,000 --> 00:04:57,000
substances in suspension, it will be very difficult for them to breathe.

58
00:04:57,000 --> 00:05:04,000
It is the same as if we get in the middle of a sandstorm, it would be very difficult to breathe.

59
00:05:04,000 --> 00:05:09,000
Modification of water properties, here we talk about smell and taste.

60
00:05:09,000 --> 00:05:14,000
If instead of opening the tap and a completely transparent water comes out, it starts to have

61
00:05:14,000 --> 00:05:19,000
a brownish tone, well, it doesn't give us much confidence.

62
00:05:19,000 --> 00:05:27,000
Within chemical pollutants, we are going to distinguish between organic, inorganic and gas pollutants.

63
00:05:27,000 --> 00:05:32,000
Let's start with the organic ones, here we have, on the one hand, carbohydrates and proteins,

64
00:05:32,000 --> 00:05:39,000
which usually come from waste water, from a house, it always ends up in the water,

65
00:05:39,000 --> 00:05:44,000
in a certain part of the food we eat, that food that we eat will end up in the sea.

66
00:05:44,000 --> 00:05:52,000
Fats, we have industrial waste, even the fat from our kitchen, when we wash a pan,

67
00:05:52,000 --> 00:05:57,000
that fat will go through the sink and end up in a deporator, which if it is not filtered well,

68
00:05:57,000 --> 00:06:03,000
it ends up in the river, or even there are many people who still throw the oil used by the sink,

69
00:06:03,000 --> 00:06:08,000
which pollutes a lot, I tell you, and there are containers to deposit it.

70
00:06:08,000 --> 00:06:13,000
It can also appear in pesticides and phenols, because they are simply substances that are used

71
00:06:13,000 --> 00:06:18,000
in conventional agriculture, in chemical agriculture, to prevent weeds from growing.

72
00:06:18,000 --> 00:06:23,000
They are quite harmful as endocrine disruptors.

73
00:06:23,000 --> 00:06:26,000
Let's see, among the effects that chemical pollutants can have,

74
00:06:26,000 --> 00:06:30,000
on the one hand, are the odors, that of bad odor and bad taste in water,

75
00:06:30,000 --> 00:06:33,000
and on the other hand, those endocrine disruptors.

76
00:06:33,000 --> 00:06:38,000
I have posted a video in the virtual lab that explains this topic of endocrine disruptors,

77
00:06:38,000 --> 00:06:40,000
so you can see it now.

78
00:06:40,000 --> 00:06:43,000
Let's move on to inorganic pollutants.

79
00:06:43,000 --> 00:06:49,000
Here we have several types, on the one hand, we have the alteration of pH,

80
00:06:49,000 --> 00:06:54,000
the vertices can be acidic, they can be basic, they can have neutral pH,

81
00:06:54,000 --> 00:06:58,000
and that will modify the pH of the water.

82
00:06:58,000 --> 00:07:02,000
Where does it come from? It can be both industrial and domestic.

83
00:07:02,000 --> 00:07:07,000
For example, when we use bleach to clean, which now with the issue of COVID is quite common,

84
00:07:07,000 --> 00:07:14,000
it has a very basic pH. When water is poured, the water will be modified to that basic pH.

85
00:07:15,000 --> 00:07:19,000
The salts. Where do the salts come from? They can come from a domestic use,

86
00:07:19,000 --> 00:07:25,000
the salt, for example, that we use for washing dishes, or a marine intrusion.

87
00:07:25,000 --> 00:07:27,000
How does a marine intrusion occur?

88
00:07:27,000 --> 00:07:35,000
Let's imagine that we are close to the coast and we are extracting fresh water from an underground aquifer.

89
00:07:35,000 --> 00:07:39,000
That underground aquifer, as it is close to sea water,

90
00:07:39,000 --> 00:07:45,000
it may happen that if we extract water, the sea water enters the aquifer

91
00:07:45,000 --> 00:07:51,000
and that causes a contamination of salt and the aquifer becomes unsuitable for consumption.

92
00:07:51,000 --> 00:07:56,000
What does it cause? The salinization of an aquifer or it can also cause increased hardness.

93
00:07:56,000 --> 00:08:00,000
Water, I don't know if you know, but it can have different degrees of hardness.

94
00:08:00,000 --> 00:08:06,000
For example, in Madrid the water is soft because we are close to the mountains

95
00:08:06,000 --> 00:08:10,000
where we extract the water and the soil, because of its characteristics,

96
00:08:10,000 --> 00:08:16,000
because of which the rivers that reach Madrid flow, it does not provide much calcium carbonate,

97
00:08:16,000 --> 00:08:25,000
which is what gives it that hardness, but if we are located, for example, in Almería or Alicante or Tarragona,

98
00:08:25,000 --> 00:08:29,000
those waters will have a lot of hardness because the rivers, throughout their journey,

99
00:08:29,000 --> 00:08:33,000
will make a contribution of calcium carbonate and will increase the hardness of the water.

100
00:08:33,000 --> 00:08:39,000
This can cause washing machines to break down due to that increase in lime.

101
00:08:39,000 --> 00:08:49,000
Heavy metals. The industry often uses heavy metals or are residues that are produced in the industry.

102
00:08:49,000 --> 00:08:55,000
These can cause bioaccumulation, which is good because in living beings,

103
00:08:55,000 --> 00:09:00,000
as we go up in the trophic chain, there are more and more of those heavy metals.

104
00:09:00,000 --> 00:09:05,000
I have posted another video on the virtual egg so you can see what bioaccumulation is and the problems it generates.

105
00:09:05,000 --> 00:09:10,000
More chemical and inorganic pollutants. We have nitrogen derivatives.

106
00:09:10,000 --> 00:09:15,000
Remember that nitrogen was also a basic component of life,

107
00:09:15,000 --> 00:09:22,000
with which animal and agricultural remains can generate an excess of nitrogen in the soil.

108
00:09:22,000 --> 00:09:26,000
This can cause eutrophication, which we are going to see today,

109
00:09:26,000 --> 00:09:29,000
or that a series of toxic nitrates appear.

110
00:09:29,000 --> 00:09:34,000
In fact, nitrates are the main source of underground water pollution,

111
00:09:34,000 --> 00:09:37,000
because of those nitrates that are added to agriculture.

112
00:09:37,000 --> 00:09:39,000
Phosphorus derivatives.

113
00:09:39,000 --> 00:09:44,000
Detergents, so that they can clean more and leave the clothes white and shiny,

114
00:09:44,000 --> 00:09:46,000
have a lot of phosphorus.

115
00:09:46,000 --> 00:09:49,000
That phosphorus facilitates the eutrophication processes.

116
00:09:49,000 --> 00:09:53,000
We are going to explain what eutrophication is inside NADO, so I won't go into it anymore.

117
00:09:54,000 --> 00:09:59,000
And sulfur, which can have a domestic or industrial use, has a purging effect.

118
00:09:59,000 --> 00:10:01,000
Gases. What gases can we find?

119
00:10:01,000 --> 00:10:04,000
Yes, in the water we have many dissolved gases too.

120
00:10:04,000 --> 00:10:13,000
Among them, hydrogen sulfide and methane can be domestic or appear as infiltrations

121
00:10:13,000 --> 00:10:19,000
and cause a smell and taste in the water that are not desirable.

122
00:10:19,000 --> 00:10:21,000
Biological pollutants.

123
00:10:21,000 --> 00:10:23,000
There can be biological pollutants.

124
00:10:23,000 --> 00:10:29,000
It may be strange to think that water has something more than water and some salts,

125
00:10:29,000 --> 00:10:35,000
but in most countries in the world, water is not totally sterile,

126
00:10:35,000 --> 00:10:46,000
but the tap water has a lot of living or dead organisms that we can ingest.

127
00:10:47,000 --> 00:10:52,000
In addition, there may be areas where, due to their characteristics,

128
00:10:52,000 --> 00:10:56,000
one type of organism or another proliferates more and it can cause problems or not.

129
00:10:56,000 --> 00:10:58,000
Bacteria can appear.

130
00:10:58,000 --> 00:11:03,000
For example, cholera is a problem even in areas where water is potable.

131
00:11:03,000 --> 00:11:07,000
Imagine that here the water is potable, but due to some problem,

132
00:11:07,000 --> 00:11:10,000
imagine that there is an earthquake, that there is a hurricane,

133
00:11:10,000 --> 00:11:12,000
that there is a storm called Philomena,

134
00:11:12,000 --> 00:11:17,000
the tap water is cut off.

135
00:11:17,000 --> 00:11:20,000
Notice that in Texas it happened two days ago.

136
00:11:20,000 --> 00:11:22,000
I'm not talking about anything strange.

137
00:11:22,000 --> 00:11:25,000
And this potable water, people need to drink it.

138
00:11:25,000 --> 00:11:26,000
Where does the water come from?

139
00:11:26,000 --> 00:11:30,000
Many times, in certain places, people go to rivers,

140
00:11:30,000 --> 00:11:36,000
to areas where there are natural sources, to extract the water.

141
00:11:36,000 --> 00:11:39,000
If the water is not well treated, it can contain bacteria.

142
00:11:39,000 --> 00:11:44,000
Like cholera, which can cause a lot of problems.

143
00:11:44,000 --> 00:11:46,000
There may also be viruses.

144
00:11:46,000 --> 00:11:51,000
Most viruses do not resist well in water, so we do not worry much about them.

145
00:11:51,000 --> 00:11:55,000
Protozoa. Parasitic protozoa are very annoying, I tell you.

146
00:11:55,000 --> 00:11:57,000
And parasitic worms.

147
00:11:57,000 --> 00:12:00,000
If you remember, when you were little, they told you,

148
00:12:00,000 --> 00:12:03,000
if you bite your nails, intestinal worms can enter you.

149
00:12:03,000 --> 00:12:05,000
Well, yes, they can appear.

150
00:12:05,000 --> 00:12:08,000
And many of them can appear in large quantities.

151
00:12:08,000 --> 00:12:11,000
Most of us have intestinal worms and we do not find out.

152
00:12:11,000 --> 00:12:13,000
In general, nothing happens.

153
00:12:13,000 --> 00:12:15,000
But hey, they can be unpleasant.

154
00:12:15,000 --> 00:12:18,000
I have posted a video on the subject of cholera,

155
00:12:18,000 --> 00:12:21,000
because I tell you that it seems like something that will never affect us,

156
00:12:21,000 --> 00:12:26,000
but it could affect us, or even if we travel to third countries.

157
00:12:26,000 --> 00:12:31,000
Let's talk now about a type of contamination of surface waters.

158
00:12:31,000 --> 00:12:34,000
In this case, eutrophication.

159
00:12:34,000 --> 00:12:35,000
Definition.

160
00:12:35,000 --> 00:12:38,000
Well, eutrophication is the increase in primary productivity,

161
00:12:38,000 --> 00:12:40,000
algae, oceans, bacteria,

162
00:12:40,000 --> 00:12:42,000
caused by the introduction of bio-nutrients,

163
00:12:42,000 --> 00:12:44,000
with nitrogen and phosphorus,

164
00:12:44,000 --> 00:12:48,000
through agricultural and livestock vertices.

165
00:12:48,000 --> 00:12:51,000
What happens so that there is eutrophication?

166
00:12:51,000 --> 00:12:55,000
First, we have to have waters that are stagnant,

167
00:12:55,000 --> 00:12:57,000
or that have a very slow course.

168
00:12:57,000 --> 00:13:01,000
That is, eutrophication can occur in lakes, lagoons, reservoirs,

169
00:13:01,000 --> 00:13:03,000
very dry seas.

170
00:13:03,000 --> 00:13:06,000
In rivers that are running, it cannot occur,

171
00:13:06,000 --> 00:13:08,000
because there is no other option.

172
00:13:08,000 --> 00:13:10,000
The water is very oxygenated,

173
00:13:10,000 --> 00:13:13,000
and these types of processes do not appear.

174
00:13:13,000 --> 00:13:15,000
How do they occur?

175
00:13:15,000 --> 00:13:19,000
Let's imagine a lake in which animals live peacefully,

176
00:13:19,000 --> 00:13:22,000
plants in happy company,

177
00:13:22,000 --> 00:13:25,000
and an increase in phosphorus and nitrogen occurs.

178
00:13:25,000 --> 00:13:28,000
Be careful, this increase can be natural.

179
00:13:28,000 --> 00:13:31,000
It may be a time when there is a lot of production,

180
00:13:31,000 --> 00:13:33,000
for example, imagine in summer,

181
00:13:33,000 --> 00:13:36,000
when lakes decrease their volume a lot,

182
00:13:36,000 --> 00:13:38,000
because a lot of water evaporates,

183
00:13:38,000 --> 00:13:40,000
and that, in addition,

184
00:13:40,000 --> 00:13:43,000
the plants are full doing photosynthesis,

185
00:13:43,000 --> 00:13:46,000
and an increase in phosphorus and nitrogen occurs.

186
00:13:46,000 --> 00:13:48,000
But what we study,

187
00:13:48,000 --> 00:13:51,000
precisely as anthropogenic contamination,

188
00:13:51,000 --> 00:13:53,000
this increase in phosphorus and nitrogen,

189
00:13:53,000 --> 00:13:59,000
is generally due to all those agricultural activities,

190
00:13:59,000 --> 00:14:03,000
which use a lot of phosphorus and nitrogen for their chemical fertilizers,

191
00:14:03,000 --> 00:14:05,000
or from households,

192
00:14:05,000 --> 00:14:10,000
it can also occur because the detergents we use have phosphorus,

193
00:14:10,000 --> 00:14:16,000
and a continuous flow is produced to areas where it is a little oxygenated,

194
00:14:16,000 --> 00:14:18,000
this increase can occur.

195
00:14:18,000 --> 00:14:20,000
Ok, increase in phosphorus and nitrogen.

196
00:14:20,000 --> 00:14:22,000
Who are the first to grow?

197
00:14:22,000 --> 00:14:25,000
The first to grow are phytoplankton.

198
00:14:25,000 --> 00:14:29,000
This phytoplankton is made up of diatoms,

199
00:14:29,000 --> 00:14:32,000
then chlorophyces can also appear,

200
00:14:32,000 --> 00:14:34,000
which is a type of algae,

201
00:14:34,000 --> 00:14:36,000
and cyanophyces, another type of algae.

202
00:14:36,000 --> 00:14:39,000
What happens when phytoplankton grows?

203
00:14:39,000 --> 00:14:43,000
Basically, the surface of the water becomes cloudy.

204
00:14:43,000 --> 00:14:45,000
Of course, they grow a lot, a lot, a lot,

205
00:14:45,000 --> 00:14:51,000
and prevent the sunlight from reaching the lower layers of that lake.

206
00:14:51,000 --> 00:14:53,000
There is a lot of oxygen that goes to the atmosphere.

207
00:14:53,000 --> 00:14:56,000
Yes, it is very good, there is a lot of oxygen in the atmosphere,

208
00:14:56,000 --> 00:15:00,000
but all the lower layers of that phytoplankton will not get sunlight.

209
00:15:00,000 --> 00:15:02,000
What happens over time?

210
00:15:02,000 --> 00:15:06,000
The vegetation that is below that phytoplankton begins to die.

211
00:15:06,000 --> 00:15:10,000
When it dies, the organic matter accumulates in the bottom.

212
00:15:10,000 --> 00:15:14,000
Remember that these are areas where there is very little oxygenation,

213
00:15:14,000 --> 00:15:17,000
so if oxygen cannot reach the bottom,

214
00:15:17,000 --> 00:15:20,000
because the oxygen of the phytoplankton, which is at the top,

215
00:15:20,000 --> 00:15:23,000
goes to the atmosphere, but does not go to the water.

216
00:15:23,000 --> 00:15:27,000
In addition, the bacteria that are in the bottom consume that organic matter,

217
00:15:27,000 --> 00:15:29,000
decreasing oxygen more and more,

218
00:15:29,000 --> 00:15:33,000
with which, in the end, all the animals end up dying

219
00:15:33,000 --> 00:15:35,000
due to lack of oxygen,

220
00:15:35,000 --> 00:15:38,000
and an area is produced that we call anoxic,

221
00:15:38,000 --> 00:15:40,000
that there is no oxygen in that area.

222
00:15:40,000 --> 00:15:45,000
In that area there would be a large amount of hydrogen sulfide,

223
00:15:45,000 --> 00:15:48,000
methane, ammonia, which produces a terrible smell.

224
00:15:48,000 --> 00:15:51,000
It smells like rotten eggs.

225
00:15:51,000 --> 00:15:53,000
What solution is there for this?

226
00:15:53,000 --> 00:15:55,000
Basically, an oxygenation.

227
00:15:55,000 --> 00:15:58,000
First, stop pouring, obviously,

228
00:15:58,000 --> 00:16:00,000
and then try not to go further,

229
00:16:00,000 --> 00:16:02,000
causing an oxygenation of the area.

230
00:16:02,000 --> 00:16:05,000
It is complicated depending on the size,

231
00:16:05,000 --> 00:16:08,000
but if we can control those pourings,

232
00:16:08,000 --> 00:16:11,000
we will surely get the ecosystem to recover.

233
00:16:12,000 --> 00:16:16,000
A variant of eutrophication in the sea would be red tides.

234
00:16:16,000 --> 00:16:20,000
It is similar to eutrophication, but it occurs in the sea,

235
00:16:20,000 --> 00:16:24,000
and a phytoplankton eclosion occurs with toxins.

236
00:16:24,000 --> 00:16:29,000
They are generally bacteria that have that reddish color

237
00:16:29,000 --> 00:16:31,000
because they have carotenoids,

238
00:16:31,000 --> 00:16:34,000
and they cause toxicity in the water.

239
00:16:34,000 --> 00:16:36,000
Many species die.

240
00:16:36,000 --> 00:16:40,000
In certain areas they appear more or less frequently.

241
00:16:40,000 --> 00:16:44,000
Red tides have been recorded for thousands of years.

242
00:16:44,000 --> 00:16:48,000
Since the beginning of writing, red tides have been recorded in the seas.

243
00:16:48,000 --> 00:16:51,000
But what happens if we have a sea with an excess of phosphates

244
00:16:51,000 --> 00:16:53,000
and an excess of nitrogen?

245
00:16:53,000 --> 00:16:57,000
Those red tides will be favored to occur more frequently.

246
00:16:57,000 --> 00:16:59,000
And so far today's class.

247
00:16:59,000 --> 00:17:01,000
With this we finish.

248
00:17:01,000 --> 00:17:07,000
I have also posted a video about eutrophication in the smaller sea,

249
00:17:07,000 --> 00:17:09,000
which I hope you find interesting.

250
00:17:09,000 --> 00:17:11,000
Until the next day.