Assessing the degradability of biodegradable-packaging base material through the insertion of organic solid waste deriving from composting process

Abstract

The intensified use of plastic materials in recent decades had different impacts on the environment. This issue has encouraged both research about, and the development of, alternatives to minimize the massive amount of plastic items used by society. The so-called biodegradable materials, mainly starch-based compounds, have emerged from this context. Although these materials show limited mechanical properties and low water resistance, they can be mixed to several reinforcing agents to help overcoming their shortcomings in order to be applied at larger scale without jeopardizing their biodegradability. Thus, the aims of the current study are to assess the biodegradability of a starch-based biopolymer by adding different malt bagasse (waste deriving from beer production processes) concentrations to it; as well as assessing and monitoring parameters linked to the composting process of this mix added with solid organic waste. Biodegradation was determined by visually assessing the investigated material, as well as by monitoring parameters, such as pH, temperature, humidity and organic matter and by recording them in spreadsheet, for descriptive data analysis purposes. Results have evidenced lower biological activity in the compost and, consequently, higher resistance to biodegradation than those observed for the control composting unit. It was hard identifying the material after three-week composting. After four weeks, it was not possible identifying the biopolymer. This finding suggested biopolymer biodegradation and incorporation to the substrate. The investigated material underwent changes in its mechanical properties during composting. Therefore, it is possible saying that it is fully biodegradable by all malt bagasse compositions, under composting conditions.