Biography
Biography: Sedki BEN ALI
Abstract
Interest towards applying biodegradable plastics as a substitution for the conventional plastic is promising and the introduction of biodegradable materials which can be disposed directly into the soil can be a possible solution to the waste accumulation problem. But before intensive use of these materials it is necessary required to examine their safety for the environment. Once these materials are buried, they could represent a threat for soil contamination and food produced. A biodegradation test of two biodegradable mulching films (mainly composed of starch and PBAT) on soil medium under aerobic conditions was developed using an inert medium called pozzolan. This medium was activated by consortia (addition of microorganisms extracted from two different soil modalities in order to study the impact of biodiversity on the biodegradation rate) and a mineral solution. A follow up of the evolution of physical and chemical material parameters (DSC, TGA, SEM, RMN1H and IR), as well as the evolution of the microbial biomass (microbial C determined by using the chloroform fumigation extraction method, DNA extraction, CFU evolution) was investigated during the test period. The mineralization rate was evaluated based on the CO2 trapped (NaOH solution) during the respiration of microorganisms. Terrestrial ecotoxicity test was performed on plants and earthworms to show a potential toxic effect and to establish a dose-effect relation according to 11268-1:2012 and ISO 11269- 2:2013.