The complexity of any plastic recycling initiative lies in the heterogeneous nature of the post‐consumer commingled plastic waste stream: recycling treatments are challenging without prior reliable sorting. A suitable identification system should be able to recognize different plastics and blends. Nowadays, the main technique used as quality control in plastic waste sorting centers is differential scanning calorimetry, whose result can be purely qualitative or semi‐quantitative, since only the crystalline fraction is evaluated. Moreover, the time required for data acquisition is relatively long. Infrared spectroscopy is an alternative, faster technique extensively used in applied research, but not widely utilized in industry. In this work, the cross‐use of infrared spectroscopy and calorimetry is tested in a real, practical case: the quality control of recycled pellets (namely composed of polyolefins only), which represent the output of a commingled plastic recycling plant and are used as secondary raw materials for different applications. Appropriate infrared spectroscopy calibration curves were built to allow the quantitative analysis with respect to the most common polymers found in the commingled plastic waste stream; the composition and contaminants in the recycled pellets were thereby determined and tracked through different production batches through the cross‐use of the two techniques outlined above.
This study examines a lightweight thermal and acoustic insulation material, produced starting from a hydrogel‐based mixture composed by renewable biopolymer and fiberglass waste powders. The gel 3D porous network is preserved after water removal by sublimation, resulting in a lightweight thermal and acoustic insulation material with good overall performance. Mechanical, thermal, and acoustic properties can be tuned as a function of biopolymer and additives concentration. This material addresses environmental concerns both in terms of secondary raw sources use and fiberglass waste disposal. Moreover, contrary to mineral wools currently on the market, it can overcome the problem of fiber release, with significant human health benefits. Thanks to its good properties and its fabrication process based on a circular economy approach, it can be appealing for thermal and acoustic insulating applications in building and industrial sectors and also in terms of environmental footprint.
Several studies have presented the effects of environmental noise on communities, focusing attention on sleep time events. The noise introduced into a dwelling is mostly evaluated using the A-weighted sound pressure level (LAeq) as the only parameter to determine the perceived disturbance. Nevertheless, if noise is produced by activities or sources characterised by a low frequency contribution, the measurement of LAeq underestimates the real disturbance, in particular during sleep time. The aim of this contribution is to analyse the low frequency disturbance phenomenon into technical and scientific literature and to investigate if any possible objective method is available in order to assess noise disturbance inside dwellings.