Waste treatment

The main objective of this method is the separation of recoverable materials and the stabilisation of organic matter, transforming it into compost or biogas for energy use. TMB facilities, such as the one in Hornillos, located in Quart de Poblet (Valencia), reduce the volume of waste destined for landfill, improve the recovery of recyclable materials, and minimise the environmental impact of urban waste management. 

The Hornillos Mixed MSW Mechanical-Biological Treatment Plant, managed by Valoriza, is an example of efficiency and sustainability in waste management. This plant, which began operating in 2005, has four separation lines for municipal solid waste (MSW) and a specific line for medical waste. With a treatment capacity of 400,000 tonnes per year, the plant can recycle 25,000 tonnes of material and produce 35,000 tonnes of compost annually. Its advanced technology includes fermentation processes in closed tunnels and an automatic maturation park, which guarantees efficient and controlled waste treatment. 

This method ensures the complete oxidation of the waste in an environment with an excess of oxygen, reaching temperatures ranging from 900°C to 1200°C. Incineration not only significantly reduces the volume of waste, but also generates useful by-products such as combustion gases and solid residues that can be used for energy purposes. This process transforms the heat generated into thermal and electrical energy, contributing to energy efficiency and sustainable waste management.

An outstanding example of the application of this process is the mechanical and biological treatment plant (MBT) with waste-to-energy conversion located in Mataró, Barcelona, managed by Valoriza. This plant, with a nominal capacity of 12 MW, has been designed for the energy recovery of solid urban waste from the Maresme region. Commissioned in 2010, the plant not only processes waste through composting and anaerobic digestion, but also ensures compliance with EU Directive 2000/76/EC for waste incineration. With a capacity to recycle 16,000 tonnes of material per year and produce 27,000 tonnes of compost, the facility generates 96 GWhe of energy annually through thermal treatment and 13 GWhe through anaerobic digestion, making a significant contribution to energy and environmental sustainability. 

This process is used in water treatment plants to remove, by means of high temperatures and evaporation, as much water as possible from the dewatered sludge. During thermal drying, the free water and a part of the capillary water are removed, although the removal of the intracellular and molecular water is more complex and requires more energy. This method significantly reduces the volume of sludge, leaving it with a very low moisture content, usually between 1% and 3%

An outstanding example of this technology is the Butarque thermal sludge drying plant in Madrid, Spain. This plant has two indirect convection and total condensation drying lines and has been in operation since April 2003. With an evaporation capacity of 110,000 tonnes of dewatered sludge per year, the plant can produce up to 28,300 tonnes per year of dry biosolids with 90% dry matter. This facility, equipped with three natural gas engines with a total installed capacity of 18 MW, represents a significant advance in the management of sewage waste, contributing to the sustainability and efficiency of wastewater treatment.

These facilities optimise the transport of waste by allowing collection vehicles, which have limited capacities, to transfer their load to larger vehicles suitable for longer distances, thus improving efficiency and reducing wear and tear on the vehicle fleet.

During the primary, secondary, and tertiary phases of water treatment, physical, chemical, and biological processes are used to separate and treat the sludge, which contains polluting and potentially hazardous substances. In the primary phase, floating components, litter, and sand are removed from the wastewater flow, while in the subsequent phases, stabilisation, thickening and disinfection of the sludge is ensured prior to its final disposal.

At the Guadalete sludge treatment plant, an integral stabilisation and composting process is carried out, which allows the sludge to be transformed into compost that can be used as fertiliser in the agricultural sector. This plant, which started operating in March 1994, has a production capacity of 50,000 tonnes of sludge per year and produces approximately 10,000 tonnes of compost per year. The operation of this plant not only contributes to the safe and efficient management of sludge, but also promotes sustainable practices by converting a potentially hazardous waste into a valuable resource for agriculture.

These tyres, which are not suitable for direct reuse, must be processed to recover valuable materials or to be used as fuel in industrial processes. The treatment of tyres includes various shredding stages, which reduce their size and separate components such as steel and textile, obtaining useful products such as recycled rubber.

The Chiloeches plant carries out a complete recycling process that includes primary and secondary shredding and granulation. This plant, which began operating in July 2009, has the capacity to process up to 30,000 tonnes of tyres per year. The rubber obtained is used in a variety of applications, from construction materials and sports surface coatings to the manufacture of rubber-modified asphalt, which offers significant thermal and economic advantages. The Chiloeches plant not only contributes to waste reduction and mitigation of environmental problems associated with improper tyre storage, but also fosters the circular economy by transforming waste into useful resources.

The process includes the shredding of wood waste, separation of metals, along with the classification and storage of waste for subsequent treatment. The plant also recovers aggregates through screening and cleaning processes and stores the recycled materials for shipment to specialised facilities.

With a capacity of 300,000 tonnes per year, the Gardelegui plant is crucial for promoting the recycling and reuse of materials in construction, preventing copious quantities of this type of waste from ending up in landfills. The facility operated by Valoriza not only reduces environmental impact, but also boosts the circular economy, ensuring that resources are used efficiently and sustainably.