Testing Anaerobic Biodegradability of Polymers in a Laboratory-Scale Simulated Landfill

The objective of this research was to develop an improved technique for measurement of anaerobic biodegradability that more closely simulates decomposition in landfills. Tests were conducted in 2-L reactors that contained a mixture of 14 C-labeled test material, fresh refuse, and decomposed refuse as a seed. The four materials evaluated included a pure cellulose, a lignified cellulose (LC), a citric acid cross-linked cellulose (x-C), and a polyacrylate absorbent gel material (AGM). Material biodegradability, as measured by production of 14 CH 4 and 14 CO 2, was 55.5, 25.7, 52.0, and 2.5% for purified cellulose, LC, x-C, and AGM, respectively. Total recovery of radiolabel, after measure ment of residual label in the leachate and decomposed refuse, was 77.4, 95.2, 74.1, and 66.7%, respectively. The reactor system provided repeatable results and simulated the refuse decomposition cycle in 6 months. Tests demonstrated that the biodegradability of x-C, a newly developed material, was comparable to that of pure cellulose and greater than that of LC. Cellulose in both forms is typically buried in landfills.