Packaging materials can arise from a wide range of sources and are commonly used for food, medicine, household appliances, and items to enclose or protect products during distribution, storage, sale, delivery, and use. The choice of material (paper, plastic, glass, wood, metal, multi-layer or other packaging) to be used depends on the type and properties of product, the purpose of packaging, and the price. The aim of the investigation is to analyse the morphological composition of packaging waste collected separately in Kaunas (Lithuanian) private households and to evaluate its recycling possibilities. The mixture of paper, plastic, and metal packaging waste was analyzed in the winter and spring (one time per month) in the waste management company JSC "Kauno švara".

Multilayer packaging, commonly referred to as composite materials, is widely utilized in food storage, distribution, and consumption. The employment of plastic packaging, which consists of multiple layers of polymers, ink, paper, and metal, has elicited concerns regarding its detrimental impact on the environment. This article presents an in-depth study of the delamination process of multilayer plastic waste (MLPW) recycling, which is deemed as an effective solution for MLPW recycling. This study aimed to examine the effects of temperature, concentration, width, and ultrasound on the separation of layers in multilayer packaging. The results demonstrated that ultrasound is the most influential factor with nitric acid concentration ranking as the second most significant factor. The findings also disclosed considerable disparities among the time frames, and the impacts of various factors, such as temperature and concentration, lay the groundwork for further investigation into this process. The study underscores the importance of temperature and nitric acid concentration, which can inform the design of future experiments and the development of more efficient methods for layer separation.

The feasibilities of silicon recovering from solar cell waste (SCW) by treatment with nitric acid at its concentrations of 1, 2, 3 and 4M were investigated. The research results have shown that complete leaching of aluminum from the silicon matrix is not possible. It can be explained by formation of aluminum compounds with oxygen and silicon on the aluminum particles. Total silver leaching is achieved at maximal 4M concentrations of nitric acid. The influence of nitric acid concentrations on the leaching efficiency of these metals is significantly reduced at higher temperatures (up to 50°C). Higher metal leaching efficiency is characteristic of larger SCA particles under more favourable spatial conditions for penetration of nitric acid ions.