Polyhydroxyalkanoates or PHAs are high quality bioplastics produced by bacteria. These bacteria produce the material when there is an abundance of food, to eat it when food is scarce. A collaboration between several Dutch water authorities and various other institutions have researched the possibility to make PHA with the active bio mass deriving from sewage treatment. The resulting bioplastic is 40 per cent better than current PHAs.

The Dutch water authorities are working on reclaiming raw materials from sewage treatments. Before, we showed an example of making products out of used (and cleaned) toilet paper. The PHARIO project, which stands for ‘PHA uit RIOolwater’ (Dutch for ‘PHA from sewage’), showed that active sludge from sewage treatments can be used as a raw material for the production of PHA.

PHA breaks down relatively quickly in water, which makes sure that it won’t contribute to the already existing plastic soup of microplastic in surface waters.

The environmental impact of the new PHA from active sewage sludge is much lower than plastics made from petroleum, but also than comparable bioplastics. The material can be recycled more than five times. Another advantage of the new PHA is that no food sources are used to make it, as opposed to many other bioplastics, which derive from for instance sugar.

The PHARIO project proved that it is possible to make plastic from sewage sludge. In Bath, they were able to produce one kilogram of the material per week over a 10-month period, but the aim is to scale up drastically and have a commercial plant ready between 2019 and 2021. The company Pezy Group successfully created business card holders using the plastic (see photos).

The PHARIO project is looking for investors and entrepreneurs to make products out of it.

Photos business card holders: Pezy Group