Landfilling by Sardinia

One of the waste trucks

Today, we visited a landfill outside of the city named Ecoserdiana. Originally it was a municipal solid waste facility (MSW) which means that all of the trash that the regular population creates went there. In the year 2008, it was non-renewed for MSW and now it only deals with industrial waste. Not having taken a lot of classes about landfilling or dealing with solid waste made this tour a bit harder for me to understand in terms of processes and exactly how everything is done. The lecture in class did help the day before, but going into the tour I was unsure of how much of that information I absorbed.

Top view of the landfill, right side is half of the old MSW landfill
while the left is the other side of the MSW being covered with industrial waste

The darker grey is bottom ash from incineration while the light grey is from the top

Anyways, what I found the most interesting was the history of the facility as well as how they are preparing for the future. The landfill itself is actually 40 acres and contains six different landfills. There is a lot of preparation of the area that goes into a landfill, such as lining and clay in order to make sure the waste is contained. Landfills produce leachate which is a liquid that is produced from rainwater or from the waste itself that has been contaminated. Since the facility used to deal with more MSW, there were a lot more organic products in the waste meaning that methane gas was being produced. This gas was then transported down the road through piping and used as biofuel to create energy. The facility still produces biofuel, but since the facility can no longer handle MSW and deals mostly with waste from incineration, there is less biogas being produced. Yet, they can still extract methane from the MSW below. The incineration waste is actually being placed on top of an old MSW landfill which I thought was pretty interesting creating a sort of two-story landfill. The methane gas that is collected is then transported down the road through the pipes where it is converted into energy. All of the energy is sold back into the grid. Currently, they are looking at putting in and anaerobic digestion plant near the biogas facility where they would handle organic waste in order to be able to turn more biogas from the anaerobic digestion into energy. This would compensate for the methane gas that will eventually run out from the landfill. They also have a solar farm there producing energy. Both solar and biogas have incentives from the government, but solar has more of an incentive because it's a much cleaner process.

Data monitoring tower for the landfill

Biogas to energy facility

The idea of having so many different facilities near each other in a type of district is really neat I think. A lot of the different processes can relate to each other and work towards creating more renewable and sustainable energy and provide more sustainable waste management. One system could provide energy for another system and so on. Having a system like the one that Ecoserdiana is planning on creating would help the USA when it comes to waste management. After learning about how the USA manages waste, we could definitely benefit from following the lead of the EU. Maybe Italy would be a decent starting point since no one can compete with the Germans when it comes to waste management. Also, fun fact, the engineers who were in charge of both the landfilling and the biogas turning into energy were women.

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