Blog #3

Today we went on our first technical site visits to a paper recycling facility (the largest in Sardinia), a composting facility, and an incinerator about 25 minutes from the guesthouse. Andrea Barsant, a production manager, gave us a tour of the paper recycling factory in the morning. There were three main areas: the sorting area, the production area, and the transformation area (which all have their own unusual smells). I thought that the production process was the most interesting because the recycled paper is constantly moving when it is being made. It starts in the pulper as a mix of 95% water and 5% paper, and it is being stirred by spinning blades at the bottom of the tank. The mix then goes to a conveyor belt that takes out water by gravity, suction, and compression until its 50% water and 50% paper. Finally, the mix goes through a series of rollers in a dryer that evaporates the rest of the water. The paper is rolled onto a big cylinder for 80 mins, which produces 1600 meters of paper. The transformation area was also neat because we were able to see the recycled paper made into paper bags, notebooks, yellow paper for the market, and other products. I was surprised when Andrea said that the machines used to make the paper bags was from the 80's, though he also mentioned that they have been refurbished.

I was particularly interested in the composting facility because my family composts at home, and I wanted to see how it compared to a facility making tons of compost a day. The first difference that I noticed was that the compost at the facility is a mix of 30% yard waste and 70% food waste, and the compost at my house is made of only food waste. The mix at the facility is then sent inside where it sits for 30 days. There are 5 vessels that the mix sits in, and it is moved into a new vessel every 6 days. At the bottom of the vessel, air is added to the mix to try and mimic what would be happening in the natural environment. This makes sense because at home we have to mix the compost every once in a while to get air in the bottom. The temperature at the facility is also regulated so that each mix is above 55 degrees Celsius for at least 3 days to kill any pathogens. After the mix has spent 30 days inside, it is moved to a refining area for 60 days. Then is taken outside and tested to make sure that it is good and can be sold. There is also a bio filter outside that is made of chestnut bark and cork to absorb the smell from the compost.

The last place we toured was the incinerator. This facility was definitely the biggest and loudest of the three. I thought that the most interesting thing about this place was that is is connected to the waste water treatment plant next door.The incinerator generates enough power to power itself, the waste water treatment plant, and the composting facility, so none of them have to pay for electricity. The waste water treatment plant also sends sludge to the incinerator to be dried. In return, the wastewater treatment plant provides water to the cooling tanks for the incinerator. I like that the two companies are working together and it seems very sustainable.