Italy deploys city buses as smog monsters

Four buses have been operating in Italy since this week that, thanks to a filter installed on the roof, “eat” smog and purify the air as they travel.

Cookie Monster from Sesame Street is getting some competition. He is famous for his voracious appetite for cookies -and basically everything else – but smog is a bridge too far for him.

The four ‘smog monsters’ that took to the streets of Ancona (central Italy) this week are equipped with a double filter system on their roofs. One filter stops particulate matter that is less than 10 micrometers in diameter (PM₁₀). The other filter picks up particles measuring PM_2.5. Each bus covers a different type of public transport area ranging from inner-city to rural.

4.2 billion liters

Each filter unit is capable of filtering 486,000 liters of air per hour. Assuming that each bus is in operation twelve hours a day, the filtration capacity of each system installed on the bus is 12 million liters of air per day per bus. Therefore, the four buses are capable of filtering a total of 4.2 billion liters of air during the three-month trial period.

“Once the experiment is over, we’ll be able to get indications from the same filters about the degree of pollution of the areas covered. Comparing the different filters will enable us to choose the most effective materials for the next industrial phase,” a representative from the public transport company Ansaldo Trasporti explained when asked.

Real-time filter monitoring

This company active in various transport systems is collaborating on the project with the Italian company AGT Engineering. That company operates the control center in Rome, where the most important parameters of the system are monitored in real time. The University La Sapienza in Rome also has a role in the project. As does Conerobus, the municipal transport company of Ancona.

Particulate matter with a diameter smaller than 10 micrometers and especially particulate matter PM_2.5are linked to health problems, such asthma. Road traffic is one of the main causes of this pollution in urban areas.

Elegant filter

This Italian trial of “smog buses” is the second of its kind in Europe. Two years ago, Go Ahead, one of England’s largest public transport companies, launched a trial in Southampton. The trial was expanded to cities like Manchester and Oxford in 2020. Photos from that project show the filter chamber system elegantly integrated on the roof, which resembles a streamlined air conditioner.

As yet, the Italian trial has failed to show much of the Italian bravado where the design is concerned. But no doubt that will change in the second phase.