Ultrasonication pre-treatment of combined effluents from palm oil, pulp and paper mills for improving photofermentative biohydrogen production

• Published in: Energy conversion and management Vol. 119; pp. 142 - 150
• Main Authors: Budiman, Pretty Mori, Wu, Ta Yeong
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.07.2016
• Subjects: Amplitudes; Chemical oxygen demand; Direct power generation; Effluents; Oxygen demand; Palm oil; Palm oil mill effluent; Paper mills; Photofermentation; Pretreatment; Pulp and paper mill effluent; Rhodobacter sphaeroides; Ultrasound; Wastewater reuse; Photofermentation; Palm oil mill effluent; Rhodobacter sphaeroides; Pulp and paper mill effluent; Ultrasound; Wastewater reuse
• ISSN: 0196-8904; 1879-2227
• DOI: 10.1016/j.enconman.2016.03.060

•Ultrasonication pre-treatment of substrate improved biohydrogen production.•A70T45 pre-treatment produced 872.4mL H2 with 4.48% light efficiency.•Excessive ultrasonication inhibited biohydrogen production. The improvement of batch photofermentative biohydrogen production was investigated using ultrasonication pre-treatment on a combined effluent of palm oil and pulp and paper mills. The effects of the amplitude (30–90%) and ultrasonication duration (5–60min) were investigated in terms of their influences on the biohydrogen yield and chemical oxygen demand (COD) removal. The recommended ultrasonication parameters were found at the higher ranges of amplitude and duration (A70T45). Using A70T45 ultrasonication, the production of biohydrogen at 30°C could be enhanced up to 8.72mL H2/mLmedium, with a total COD removal of 36.9%. During pre-treatment at A70T45, an energy input of 775J/mL was supplied to disintegrate complex compounds into simpler structures. As a result, an increase in the soluble organic matter concentration was achieved, which led to enhanced biohydrogen production. On the other hand, the lowest biohydrogen yield (4.67mL H2/mLmedium) and total COD removal (28.8%) were obtained in the control without pre-treatment. The enthalpy of the photofermentation process was estimated to be 141.1kJ/mol with a threshold temperature of 30.9°C based on a modified Arrhenius approach.