Study of the biodegradability of the light fraction from an hydropulper pretreatment of municipal solid waste containing compostable plastic material.

The objective of this research is to study and optimize the management of the Light Fraction (LF) from a hydropulper of an anaerobic digestion plant, with the main objective to reduce the amount of the LF disposed in landfill. In particular, basing on the results of the preliminary study of the LF characteristics, some laboratory test were carried out to assess if the LF can be biodried with the aim of removing moisture, thus reducing the weight and increasing the calorific value for a possible energy recovery. Two biodrying tests were performed: in Test 1 only LF was used, in Test 2 the LF was mixed with structural material (garden waste, mainly pruning). In Test 1 was detected a reduction of volume of the 28% and a weight loss of 48% and similar values was measured for the Test 2 (29% of volume reduction and 47% as loss of weight). An increase of biological stability and calorific value was detected after the biodrying trials.