Biodegradation of Low Density Polyethylene in Aqueous Media

Low Density Polyethylene (LDPE) is the most common packaging material used for packaging a wide range of products. The efficient disposal of these plastic materials is a herculean task as they are not easily degradable and pose detrimental effects on the environment. An efficient approach is to degrade them into simpler compounds that can be disposed safely. Out of the various degradation techniques, biodegradation is vastly used as it is more economical method. Biodegradation may either be carried out in a specific aqueous medium so designed for the most efficient degradation. The present work is on the study of biodegradation of LDPE in aqueous media. For biodegradation studies various combinations of LDPE and starch i.e., LDPE, LDPE+10% starch, LDPE+20% starch, LDPE+30% starch, LDPE+40% starch, and LDPE+50% starch samples of size 15 mm x 15 mm were used and were exposed to minimal medium in a shake flask maintained at a pH of 7.5. The inoculums of bacterial consortium were added to each flask and a control was also maintained for each set of samples. In the liquid cultures the degradation followed the same pattern i.e., the degradation increased with increase in starch content. The degradation observed on day 150was 1.53%, 1.67%, 1.50%, 5.06%, 40.65% and 54.33% for pure LDPE, 10%, 20% 30%, 40% and 50% starch blended plastics respectively. For the blended starch plastics at each level the degradation increased with time. At the lowest levels the degradation was almost uniform in the early stages but at higher starch content LDPE the degradation increased with time.