By dangerous residues we define all solid, liquid, gaseous substances that, being the product of a process of transformation, production or human consumption, contain elements dangerous to life, for both, human beings and for other species.
These wastes may or may not be recyclable, but they have one or more of the following properties considered harmful to human and ecosystem health:
- Corrosiveness. Property of strong acids and bases to oxidize or dissolve the matter with which they come in contact, due to their extreme pH conditions. They are capable of producing significant burns in organic matter.
- Inflammability. Susceptibility to spontaneously start fires and start fires.
- Toxicity. It is said of the more or less poisonous or infectious substances, that is, capable of inducing an organism that has contact with them to death or disease.
- Explosiveness. Potential to cause explosions and violent movements of matter and energy, also leading to fires.
- Reactivity. This is the name given to the tendency of certain unstable substances to quickly combine with those of the environment, thus altering their natural properties and giving rise to new substances whose impact is, in turn, unpredictable.
- Radioactivity. Phenomenon by which certain atomically unstable substances emit particles that pass through almost all existing matter producing changes in their molecular balance and can cause diseases (cancer, leukemia, etc.) or burns.
Types of hazardous waste
There is usually a whole legislation to control and tackle in time the harmful effect of hazardous waste in the world, promoting recycling and reuse of some and a responsible disposal of others.
However, tons of this type of material are currently dumped into the soils, oceans and air every day, coming from various industries and human economic activities. Based on said provenance, it is possible to classify them into:
- Urban waste. Those coming from the daily life of the cities and that are usually closely linked to the consumption and disposal of goods and services.
- Light industrial waste. Whether solid, liquid or gaseous, these are substances originating from the manufacturing industry and which often have a moderately difficult elimination and a medium impact on the deterioration of environmental health.
- Heavy industrial waste. Product of the large industries of transformation of matter, they are usually very dangerous for the environment and have a profound impact on the surrounding life.
- Combustion waste. Especially gaseous and liquid waste that the combustion of flammable substances (such as hydrocarbons that we use as fuel) releases into the environment and that are usually highly toxic to life.
- Agricultural waste. Most of it is waste organic matter that will eventually be biodegraded, but that alters the natural proportions and dynamics where it is available. However, it is common to find pesticides and pesticides among them.
- Military waste. In this category would fall the remains of weapons and war initiatives such as atomic bombs or chemical weapons, etc., as well as scrap metal and explosive materials that, even after the war, remain in the environment.
Examples of hazardous waste
- Batteries and batteries. These devices provide a small charge of electricity through chemical reactions inside them, sustained by a set of acids and heavy metals (especially mercury and cadmium). Once they are exhausted, their disposal represents an environmental inconvenience, since sooner or later their packaging oxidizes and the acid is released into the environment.
- Urban wastewater. The set of liquid and semi-solid waste from the sewage systems of cities contains not only decomposing organic matter that can be a source of diseases for man and animals, but also highly reactive burned oils, chemical residues from detergents and others. Polluting substances.
- Nuclear plant disposal. Plutonium and other long-lived radioactive materials are by-products of controlled nuclear reactions that take place in nuclear power plants. This material is highly carcinogenic and mutagenic, which is why it is placed in lead containers, the only material capable of containing radiation. The problem is that these containers, being made of lead, oxidize relatively quickly.
- Biological waste. Contaminated medical supplies, such as gowns, syringes, and other tools, are often a source of virulent infections that require careful and special treatment. Much of this material is recycled after receiving radiation doses that completely sterilize it, in nuclear reactors, but much else must be discarded.
- Industrial wastewater. Many heavy industries work with large amounts of water for cooling and other productive physical-chemical reactions, but at the end of their cycle they release water loaded with heavy metals and toxic elements, whose re-entry into the river or the sea must take place in a controlled manner, since that are loaded with sulfates or nitrates and salts that unbalance the pH and chemical balance of the environment.
- Iron filings. Product of the metallurgical industry, they are often discarded relying on their rapid oxidation process. The problem is that, being a highly reactive metal, iron forms salts and acids easily, contributing to deeper and more unpredictable chemical reactions.
- Paint and solvent residues. Many inexpensive locations use highly flammable solvents in their painting and repainting work. The incorrect disposal of these substances can lead to fires or, in particularly dramatic cases, to their accumulation and subsequent explosion, since they are usually composed of volatile hydrocarbons.
- Oil and related. The heavy hydrocarbons from which we extract energy, plastic materials, polymers and thousands of other applications, can become a hazardous waste in cases of oil spill or rupture of oil pipelines. Oil tar is dense and insoluble in water, and covers everything in its path, preventing the respiration of plants and the mobility of animals. Great ecological tragedies are due to the poor handling of these elements.
- Used fuel oils. Oils and greases from automobiles, kitchens, and other mechanical applications have flammable and reactive capabilities that make them dangerous and polluting substances. Luckily, they are perfectly recyclable in biomass production processes.
- Strong bases. Caustic bases used in the paper industry, for example, are powerful desiccants and oxidants that, released into the environment, chemically react exothermically (like potassium or sodium: they emit heat) and are capable of igniting and corroding organic matter. , in addition to altering the pH of the ecosystem in a very radical way.
- Mining waste. Above all, illegal mining – such as garimpeiros in the Amazon – uses substances to detect gold that are then fed into rivers, such as mercury. Many human populations have been poisoned by the presence of this and other metals in river and lake waters, or by ingesting previously contaminated fish.
- Agricultural residuals. More than biodegradable waste, such as plant waste, compost or other biodegradable elements, we are referring here to pesticides, pesticides and chemical fertilizers rich in nitrogen and sulfur. All these substances are washed by the rain and carried to rivers and lakes, where they modify the chemical balance of the waters or infect the bodies of edible animal species.
- Industrial toxic gases. Many industrial activities generate huge amounts of toxic gases, linked to lethal elements such as arsenic, chlorine or cyanide, and are released into the atmosphere, where some contribute to the destruction of the ozone layer, and others pollute clouds, generating thus acid rain or toxic rain to fall back.
- Suffocating gases On the other hand, many industries use or by-produce gases that are not properly toxic or lethal (such as inert gases), but that in uncontrolled quantities can displace oxygen from the air and suffocate nearby animal life, requiring careful and special handling. .
- Glass and other crystals. Glass is a widely used and quite safe material, it is true, but when disposed of improperly, it can serve as a lens to focus sunlight and thus start a fire. Many forest hectares are consumed each year by this type of unpredictable but avoidable incident.