In this study, the effect of different reaction times for thermal-alkaline pretreatment on the solubilization and biogasification of polyhydroxybutyrate (PHB) were evaluated. Thermal-alkaline pretreatment tests were performed at 73 °C and pH 13 at 0-120 h reaction times. The mesophilic anaerobic batch tests were performed with untreated and pretreated PHB samples. The increase in the pretreatment reaction time results in a 52.8-98.8% increase of the abiotic solubilization efficiency of the PHB samples. The reaction time required to achieve solubilization efficiencies of 50%, 90%, and 95% were 10.5, 52.0, and 89.6 h, respectively. The biogasification of the untreated PHB samples achieved a specific methane production rate of 3.6 mL CH4/g VSS/d and require 101.3 d for complete biogasification. The thermal-alkaline pretreatment significantly improved specific methane production rate (10.2-16.0 time increase), lag time (shortened by 76-81%), and time for complete biogasification (shortened by 21-83%) for the biogasification of the PHB samples when compared to those of the untreated PHB samples. The improvement was higher as the reaction time of the thermal-alkaline pretreatment increased. The findings of this study could be used as a valuable reference for the optimization of the biogasification process in the treatment of PHB wastes.

Abstract
1. 서 론
2. 재료 및 방법
    2.1. 재료 및 장치
    2.2. 실험방법
3. 결과 및 고찰
    3.1. 열-알칼리성 전처리의 반응 시간에 따른 PHB의가용화 효율 평가
    3.2. 열-알칼리성 전처리의 반응 시간에 따른 PHB의바이오가스화 영향 평가
4. 결 론
감사의 글
REFERENCES

• Le Thi Nhu Trang(부경대학교 지구환경시스템과학부(환경공학전공))
• 이준엽(부경대학교 지구환경시스템과학부(환경공학전공)) | Joonyeob Lee (Division of Earth Environmental System Science (Major of Environmental Engineering), Pukyong National University, Busan 48513, Korea) Corresponding author