Biodegradation behavior of PHBV films in a pilot-scale composting condition

Poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV), synthesized via microorganisms, has been paid great attention. However, its biodegradation behavior in pilot-scale composting conditions has not been investigated. In this paper, the biodegradability of PHBV containing 3 mol% of hydroxyvalerate (HV) was tested under composting conditions on both a pilot and a laboratory scale. In the pilot-scale composting conditions, parameters such as pH value, temperature and the amounts of oxygen and CO2 produced were determined periodically. In the laboratory-scale controlled composting, the evolved CO2 was measured so as to calculate the degree of biodegradation of PHBV. It was found that the biodegradation behavior of PHBV in the pilot-scale composting conditions was similar with that in the laboratory-scale. The PHBV film was completely disintegrated in the pilot-scale composting test, and the degree of biodegradation was 81% in the laboratory-scale control composting test. The variations of molecular weight and morphology of PHBV films during composting were also monitored.