The most polluting and difficult to separate waste from water

In summary, the most polluting and difficult to separate waste from water are the following:

• Pathogenic microorganisms.
• Antibiotics, drugs and hormones.
• Nitrates and phosphates.
• Insecticides and other pesticides.
• Organic compounds.
• Radioactive substances.
• Thermal pollution.

Next, in each section we talk extensively about each of the types of water pollutants .

In water as in any ecosystem (even within our body) there are numerous microorganisms. The vast majority of them are beneficial but, nevertheless, there are others that can cause infections and even death if we drink contaminated water.

The microorganisms most harmful to health and those that can most contaminate water are those from faecal waste such as the gastrointestinal bacteria Escherichia coli, Enterococus faecalis, and Clostridium perfringens or other bacteria such as Vibrio cholerae, famous for being the cause of cholera. Most microorganisms can be eliminated by chlorinating the water or through ultraviolet light, but today with the amount of antibiotics that are released into the environment it is more difficult to do so because they are becoming more resistant to these and other treatments.

Antibiotics, drugs and hormones are several examples of the so-called emerging contaminants , which are also closely related to the previous section on pathogenic microorganisms. The excessive consumption that we make of these substances is increasing their appearance in natural waters. In addition, antibiotics are also used as a prophylactic measure to prevent livestock and crops from becoming ill. Antibiotics are excreted by our bodies and reach water treatment plants through sanitation networks.

Currently, sewage treatment plants do not have the sufficient capacity to eliminate them and they are released into the natural aquatic environment in the effluent of water treatment plants. They can also reach the natural environment by leaching or diffusion and filtration from farms and crops. Once in the environment, these drugs can alter the physiology and behavior of aquatic organisms.

For example, it has been seen that excess hormones in water cause fish to change sex, thus hindering their reproduction and the increased resistance of microorganisms is of particular concern.

Both are soluble in water and are the main nutrients for photosynthetic organisms that inhabit waters such as cyanobacteria, algae, diatoms, etc. When these appear in excess, they generate problems of eutrophication or enrichment of nutrients in the water, causing the primary producers to proliferate. Learn more about What is eutrophication with this other AgroCorrn article.

The consequences of this exponential growth are that they do not let light through and also end up depleting the oxygen in the water, preventing the animals from breathing. Unfortunately, the increase in both compounds is related to human activity, especially wastewater and the excessive use of fertilizers, detergents and fertilizers.

To eliminate them completely, a very sophisticated technology is necessary, which is very expensive, which is why most water treatment plants do not eliminate nitrates or phosphates and end up reaching the waterways.

Pesticides are substances that are used to kill pests of organisms that normally harm human activities. There are pesticides to kill insects (insecticides), plants (herbicides), and fungi (fungicides) among others. Pesticides are generally applied in agriculture to prevent insects, fungi, or weeds from damaging cultivated plants.

Once applied to crops, these can reach aquatic ecosystems through surface runoff or, by seeping into the soil and contaminating groundwater . In many cases pesticides dissolve very well in water and therefore become very difficult to separate. Although there are some that degrade if exposed to light and temperature, there are others that can remain in the environment for longer and even bioaccumulate in organisms, that is, they accumulate in the tissues of plants and animals. They can also be transmitted along the food chain, this is what is known as biomagnification. Currently, the permitted concentration of pesticides in European waters is regulated by the Water Framework Directive and each country also has its own limit. In the case of Spain, water is considered safe when the total concentration of pesticides is not greater than 0.5 micrograms per liter.

This class of substances includes some of the pesticides mentioned above, but also others such as oil , gasoline and other hydrocarbons, plastics, solvents, detergents, etc. These compounds have been created by man and have complex molecular structures so they cannot be degraded by microorganisms.

In the case of plastics, preservatives and hardeners are also added that make them have an even longer life and are even more resistant to degradation. In addition, due to the amount of plastic waste that is generated daily, it is difficult to completely eliminate it from the waters as we can see, for example, in the five islands of plastic in the oceans. It is equally difficult to eliminate microplastics and nanoplastics that come mostly from their fragmentation, since there are no adequate and accessible technologies to do so today. Although important advances are being made in this field, such as The Ocean Cleanup .

On the other hand, hydrocarbons can seep into the subsoil contaminating groundwater, which makes the waters even more difficult and expensive to clean.

The radiation in the water is due to the presence of soluble radioactive isotopes therein. Radiation sources can be diverse, such as accidents or leaks in nuclear plants, illegal dumping of radioactive waste or due to natural contamination. There are natural radioactive waters due to the presence of radioactive minerals from natural nuclear reactions (tritium, radon, uranium, etc.).

Eliminating radioactive contamination from water can be a complicated and expensive task, in many cases it only requires time, although the problem is that this radiation can travel to the ground or air and above all be transmitted to living beings, causing us numerous damages and including death. Radiation in water can also be eliminated (although it also depends on what type and how it is contaminated) by applying air, with reverse osmosis or by filtering it through columns of zeolites (microporous aluminisilicate mineral) impregnated with manganese oxide as you are investigating. a group of professionals from the CIESOL (Solar Energy Research Center) of the University of Almería.

Here you can learn more about radioactive contamination: causes, consequences and solutions .

To end this list of the most polluting and difficult to separate waste from water, we mention thermal pollution.

Despite not being a substance as such, the increase in water temperatureit poses a threat to the functioning of aquatic ecosystems. Nuclear plants and industries are normally responsible for the release of hot water into the environment since they use it as a cooling system during the production of energy and other products. The rise in water temperature is especially worrisome because it prevents oxygen from dissolving in the water and causes living things to die from its lack. It can also induce physiological and behavioral changes in animals. Although an attempt is made to adjust the temperature of the water before it returns to the ecosystem, it is very difficult to get it back to ambient temperature and in many cases even a one or two degree Celsius increase in temperature can harm the receiving ecosystem.

If you want to read more articles similar to The most polluting and difficult to separate waste from water , we recommend that you enter our Pollution category .