IWWG Task Group on


TG Leader: Umberto Arena

TG co-leader: Lidia Lombardi


In the last decades, the management of solid wastes greatly changed, shifting from oversimplified procedures, such as collection of unsorted wastes and their disposal in landfills, to integrated and sustainable systems, characterized by an adequate balance between waste reduction practices, material recycling techniques, biological and thermal processes for energy recovery, and engineered landfill disposal. A modern and sustainable waste management should be defined and developed with the main aim of minimizing the use of landfills, as it is imposed by the continuously reducing space for locating sanitary landfills worldwide. Moreover, it should maximize the recovery of materials, but avoiding operations that entail excessive consumption of raw materials and energy without yielding a real overall environmental advantage. Finally, a modern integrated solid waste management system should maximize energy recovery, given that, in a life-cycle approach, energy recovery from waste allows decreasing consumption of fossil fuels and overall emissions from all energy conversion systems.

The waste management systems that are operating sustainably worldwide follow all of these criteria and demonstrate that no one process is suitable for all waste streams, and no single waste management practice (i.e. landfilling, recycling, biochemical or thermochemical conversion) can handle the full array of waste types. In particular, they confirm that thermochemical treatment of unsorted residual waste (i.e., the waste left downstream of separate collection that cannot be environmentally and economically conveniently recycled) is an essential component of any sustainable integrated municipal solid waste management system. It can play a number of important roles in an integrated waste management system, since proper handling can:

  • reduce the amount of waste, therefore preserving landfill space;
  • increase the sustainable utilization of energy from the solid waste stream;
  • allow for the recovery of minerals and chemicals from the solid waste stream which can then be reused or recycled;
  • destroy a number of contaminants that may be present in the waste stream;
  • reduce greenhouse gas emissions from anaerobic decomposition of the organic wastes.

Thermal treatment is any thermochemical conversion process that takes place at relatively high temperatures causing modifications in the chemical structure of the processed material. The three main processes available for thermochemical conversion of waste are combustion, gasification and pyrolysis.

The IWWG set up a task group on the topic of thermal treatments (TGTT), with the aim to bring together international perspectives and expertise in the field, both from academia and industry, in order to provide a reference point for the stakeholders, to follow the most advanced development in the field and to disseminate experiences to the public.

The IWWG TGTT was established in 2009 during the Sardinia 2009 12th International Waste Management and Landfill Symposium - Forte Village, Santa Margherita di Pula, Italy, October 5-9.
The Task Group, led by Prof. Umberto Arena, includes members from academia and industry, mainly from Europe, Asia and North America.

Aim of the TGTT

  • Communicating properly and to a large part of the population about process, technological and environmental aspects of the main thermal treatments able to produce energy from wastes efficiently.
  • Comparing the different processes (combustion, gasification, pyrolysis) and technologies of these treatments, for different plant sizes and for different waste types.
  • Promoting the exchange and the collaboration within the scientific community and with the industry.
  • Acting as platform for facilitating information and proposal exchange.

Contact persons:

Umberto Arena, Ph.D., Chem. Eng.
Department of Environmental, Biological and Pharmaceutical Sciences and Technologies
University of Campania “Luigi Vanvitelli”
Via A. Vivaldi, 43, 81100, Caserta, Italy
E-mail: umberto.arena(at)unicampania(dot)it
Lidia Lombardi, Ph.D., Eng.
University Niccolò Cusano
Via Don Carlo Gnocchi, 3, 00166, Rome, Italy
E-mail: lidia.lombardi(at)unicusano(dot)it

Activities carried out by TGTT in the last years