Preparation for reuse

It is the first step in the global waste treatment scheme, after the collection and removal of waste, being closely linked to waste reduction strategies. It includes recovery operations consisting of checking, cleaning or repair, through which products or product components that have become waste are prepared so that they can be reused without any other prior transformation. [1]​.

Biological treatments

They are treatment operations by biodegradation of organic matter both collected separately and that present in the rest fraction where there is no such separate collection, combining in the latter case with complementary mechanical treatments. Biological treatments for the degradation of residual organic matter can be done aerobically (composting) or anaerobically (biomethylation).[1]​.

It is an aerobic biological process (with the presence of oxygen) that, under controlled ventilation, humidity and temperature conditions, transforms degradable organic waste into a stable and sanitized material called compost. It is a biological process based on a series of biochemical reactions facilitated by certain aerobic microorganisms, such as fungi and bacteria, imitating the transformation of organic matter in nature. The treatment allows the materials to be homogenized, reduce their mass and volume, and sanitize them. It is a slow process that can last between ten and sixteen weeks.

It is an artificially accelerated biological process, also called anaerobic digestion, since it takes place in very poor oxygen conditions or in its total absence. As a result, a mixture of gases is obtained, called biogas, formed by methane and carbon dioxide (99% approx.) and the rest by other gases in a smaller proportion (water vapor, CO, N, H, HS,...). As it is a fuel gas with a high heat capacity (5,750 Kcal/m), biogas is used as a secondary energy source for the generation of electricity or other energy uses (heating, hot water, etc.).[6]​.

mechanical treatments

The purpose of these treatments is the separation and classification of materials and is used above all for the classification of light packaging waste collected separately in the yellow container (plastics and cans), although it can also be used to classify waste from non-separate collection. A combination of mechanical or automated separation processes and manual processes is used in order to recover the recoverable fractions and prepare them for subsequent commercialization. The unseparated materials are prepared to be processed either through heat treatment or landfill.[2] After receiving the materials, the most voluminous and difficult to handle components are manually separated. In some facilities, a vacuum system for bags and plastic film is implemented, while the remaining waste is taken to a rotating screen, where they are separated by size, after which they are separated and classified according to their composition. In large waste treatment plants this process is done automatically using specialized equipment. The equipment and processes used are usually the following: segregation into streams by separation by measurement with trommels or separation by shape with ballistic systems and recovery using magnetic separators (ferrous metals), Eddy separators (non-ferrous metals), automatic infrared separators (plastics and beverage cardboard) and collection with automatic aspiration (plastic film).[1]​.

Other treatments

Much of the construction and demolition waste can be recycled through a mechanical process where a series of recoverable products are obtained, suitable for use as raw materials. The general process consists of shredding the waste and various screenings to separate improper components, such as cardboard, plastics, etc. of the rest of the material, such as stone and sand, which can be reused in the preparation of concrete and mortars "Mortar (construction)") or in the manufacture of other materials.[6]​.

Preparation for reuse

It is the first step in the global waste treatment scheme, after the collection and removal of waste, being closely linked to waste reduction strategies. It includes recovery operations consisting of checking, cleaning or repair, through which products or product components that have become waste are prepared so that they can be reused without any other prior transformation. [1]​.

Biological treatments

They are treatment operations by biodegradation of organic matter both collected separately and that present in the rest fraction where there is no such separate collection, combining in the latter case with complementary mechanical treatments. Biological treatments for the degradation of residual organic matter can be done aerobically (composting) or anaerobically (biomethylation).[1]​.

It is an aerobic biological process (with the presence of oxygen) that, under controlled ventilation, humidity and temperature conditions, transforms degradable organic waste into a stable and sanitized material called compost. It is a biological process based on a series of biochemical reactions facilitated by certain aerobic microorganisms, such as fungi and bacteria, imitating the transformation of organic matter in nature. The treatment allows the materials to be homogenized, reduce their mass and volume, and sanitize them. It is a slow process that can last between ten and sixteen weeks.

It is an artificially accelerated biological process, also called anaerobic digestion, since it takes place in very poor oxygen conditions or in its total absence. As a result, a mixture of gases is obtained, called biogas, formed by methane and carbon dioxide (99% approx.) and the rest by other gases in a smaller proportion (water vapor, CO, N, H, HS,...). As it is a fuel gas with a high heat capacity (5,750 Kcal/m), biogas is used as a secondary energy source for the generation of electricity or other energy uses (heating, hot water, etc.).[6]​.

mechanical treatments

The purpose of these treatments is the separation and classification of materials and is used above all for the classification of light packaging waste collected separately in the yellow container (plastics and cans), although it can also be used to classify waste from non-separate collection. A combination of mechanical or automated separation processes and manual processes is used in order to recover the recoverable fractions and prepare them for subsequent commercialization. The unseparated materials are prepared to be processed either through heat treatment or landfill.[2] After receiving the materials, the most voluminous and difficult to handle components are manually separated. In some facilities, a vacuum system for bags and plastic film is implemented, while the remaining waste is taken to a rotating screen, where they are separated by size, after which they are separated and classified according to their composition. In large waste treatment plants this process is done automatically using specialized equipment. The equipment and processes used are usually the following: segregation into streams by separation by measurement with trommels or separation by shape with ballistic systems and recovery using magnetic separators (ferrous metals), Eddy separators (non-ferrous metals), automatic infrared separators (plastics and beverage cardboard) and collection with automatic aspiration (plastic film).[1]​.

Other treatments

Much of the construction and demolition waste can be recycled through a mechanical process where a series of recoverable products are obtained, suitable for use as raw materials. The general process consists of shredding the waste and various screenings to separate improper components, such as cardboard, plastics, etc. of the rest of the material, such as stone and sand, which can be reused in the preparation of concrete and mortars "Mortar (construction)") or in the manufacture of other materials.[6]​.