Iria Villar

By Iria Villar Comesaña, David Alves, Salustiano Mato, Xosé Manuel Romero and Bernardo Varela

The inclusion of sustainability and circular economy principles, as well as the compliance of the European requirements in municipal waste management, involves improving the waste separation, recovery and valorization. The current municipal solid waste management system of Galicia (Northwestern Spain) that includes most of the municipalities involves the treatment of biowaste (mixed in the same container with the nonorganic rest fraction) in a single management facility. This biodegradable fraction, which accounts for 42% of the total amount of household waste, is treated by incineration for energy recovery. The local government of Allariz (Galicia) undertook a project to implement a management model decentralized for biowaste separation and treatment through composting. Municipality structure (type of housing, urban and rural areas, etc.) made it necessary to implement different composting systems: home composters, community composting islands and a dynamic composter. During the first year of start-up of the management model, the level of citizen acceptance was adequate, biowaste was correctly segregated and good quality compost for soil fertilizer was obtained. So, a reduction of around 8% of the mixed waste sent to the centralized treatment facility was observed. The biowaste recovery had also resulted in a recycling improvement of all remainder fractions.

Part of the book: Solid Waste Management in Rural Areas

By David Alves Comesaña, Iria Villar Comesaña and Salustiano Mato de la Iglesia

Municipal sewage sludge is a waste with high organic load generated in large quantities that can be treated by biodegradation techniques such as composting to reduce its risk to the environment. This research studies the physicochemical variability of sewage sludge from treatment plants in the south of Galicia (Spain) and determines if it is possible to establish a protocol for the use of bulking agent depending on the composition of the sludge and the development of the composting process. Therefore, physicochemical analyses of 35 sewage sludge from different municipalities and 10 samples from the same treatment plant are discussed. Three different mixtures bulking agent:sewage sludge (3:1, 2:1, 1:1, v:v) were carried out in 30 L reactors in triplicate. Finally, proportion 2:1 was replicated six times in a 600 L reactor. High inter-sludge variability was observed specially in key parameters such as moisture and C/N ratio. Intra-variability was lower, and 2:1 proportion was the most suitable mixture since extending the thermophilic phase of the composting process at a greater degree. However, repeatability of the process at a higher scale showed different responses in the temperature evolution. Variability of sewage sludge makes difficult to establish treatment protocols although minimum requirements are necessary for proper composting.

Part of the book: Sewage

By Salustiano Mato, Carlos Pérez-Losada, María Martínez-Abraldes and Iria Villar

Waste management is one of the main environmental problems that municipalities have to address. The fulfilment of the recycling objectives imposed by the European Community requires the segregation and treatment of the municipal bio-waste. Pontevedra Provincial Council started in 2015 an innovative plan, called REVITALIZA, for the recycling of bio-waste through the promotion of composting in municipalities. REVITALIZA, which is developed in different phases, advocates the implementation of local composting (home and community composting) and small composting facilities, so that the generation of waste and the economic and environmental costs of its collection and transport are reduced. The plan is a pioneer in the training of technical personnel in the area of bio-waste management. Currently, 36 municipalities are participating in REVITALIZA in different phases of the plan, committed to locally managing bio-waste.

Part of the book: Municipal Solid Waste Management