The performance of degradable polymers within wastes management

Abstract

The use of degradable polymers for the collection and composting of organic wastes is explored within this paper. With reference to one trial where the performance of a 'degradable' polyethylene based sack for the kerbside collection of organic wastes was investigated. Areas for consideration were the impacts of the degradable polymer on the composting process and the quality of the finished product. The above trial also included a comparative study of two different types of 'degradable' polymer sacks currently on the European market (polyethylene and starch). A number of quantitative tests were conducted on the different polymers to assess the mechanisms of degradation and how this affected their suitability for the treatment of organic wastes. In this comparative study, a designated number of samples of the different polymers were contained within a 'mesh bag' and buried one metre into an open windrow comprised of green waste. The samples were extracted and weighed at given intervals. Provisional results have indicated that the polyethylene (PE) sacks are not degrading as anticipated within open windrow conditions, adversely affecting both the composting process and the quality of the finished compost product. Whilst the degradable starch based sacks appear to actively degrade within compost conditions.