Effect of Paper vs. Bioplastic Bags on Food Waste Collection and Processing

Abstract

Purpose The most abundant among the separately collected waste materials in Italy is food waste. This research aims to evaluate the influence of the type of collection bag on the food waste management chain. In Italy, the food waste collection is mainly based on bioplastic bags. As an alternative, a new type of recycled paper bag shows potential advantages. Methods The two types of collection bag were compared evaluating the weight loss of food waste during the household storage, by means of an experimental assessment simulating the domestic dynamic bag filling. Moreover, the biomethane production of bags under anaerobic conditions was measured at the lab-scale level with Biochemical Methane Potential (BMP) tests. Results During the household storage, the breathable fabric of the paper allows for higher weight losses, ranging on average between + 29 and + 44% compared to bioplastic. BMP tests, carried out under different conditions (temperature, inoculum), showed a 2–14 times higher generation of methane by paper bags compared to bioplastic bags, when referred to 1 kg of inserted food waste. Conclusions Collecting the food waste inside paper bags shows advantages compared to the use of bioplastic bags. First, the waste collection is benefitted thanks to the lower weight of material to be transported to treatment plants, leading also to the possibility of decreasing the collection frequency. Moreover, paper resulted more compatible than bioplastic with the anaerobic digestion treatment, which is currently rapidly increasing as a food waste management option. Graphic Abstract

Life cycle assessment of the food waste management with a focus on the collection bag

“…During the household storage, the waste inserted into each bag (2 kg) undergoes a weight loss because of the evaporation of a certain amount of its moisture. According to the experimental tests described in Dolci et al (2021), the following average losses were observed and considered in this assessment: 10.2% for the dedicated bioplastic bags, 8.7% for the bioplastic shopper bags and 12.9% for the paper bags. This aspect leads to different amounts of food waste that are subsequently collected.…”

“…a lower amount of waste to be collected). This aspect can be favoured by the adoption of proper collection bags that can favour the partial evaporation of water (Dolci et al, 2021).…”

“…According to tests performed by Dolci et al (2021), paper bags provide some advantages with respect to bioplastic bags. Firstly, during the household storage, the breathable fabric of paper allows for a higher weight loss of the waste material (up to +44% on average) compared to bioplastic bags.…”

“…Therefore, they are generally removed before the digestion, and this entails the dragging of a non-negligible amount of food waste embedded inside the bags (Utilitalia, 2020). On the contrary, the removal of paper bags is not required, since they are easily degraded under anaerobic conditions as stated in Dolci et al (2021), and they quickly break down and degrade together with the food waste as stated by anaerobic digestion plants currently receiving this type of bag.…”

Field studies on the deterioration of microplastic films from ultra-thin compostable bags in soil

“…Consequently, plastic waste generated from single use plastic bags has prompted much debate, forcing many governments and municipalities to adopt or promote alternatives and restrictions to their usage. Replacing petroleumbased disposable carrier bags with compostable ones has become a common option in some countries, along with use of reusable totes and paper bags and other solutions (Battista et al, 2021;Dolci et al, 2021). For example, lightweight plastic bags (thickness < 50 µm) were initially banned in Italy in 2011, and in 2018 the ban was extended to ultra-thin (UT) plastic bags (thin < 15 µm).…”