General Information
    • ISSN: 1793-821X (Print)
    • Abbreviated Title: J. Clean Energy Technol.
    • Frequency: Quarterly
    • DOI: 10.18178/JOCET
    • Editor-in-Chief: Prof. Haider F. Abdul Amir
    • Executive Editor: Ms. Jennifer Zeng
    • Abstracting/ Indexing: CNKIElectronic Journals Library, Chemical Abstracts Services (CAS), Ulrich's Periodicals Directory, Google Scholar, ProQuest.
    • E-mail:
  • Apr 25, 2022 News! JOCET Vol. 10, No. 2 is available online now.   [Click]
  • Jan 26, 2022 News! JOCET Vol. 10, No. 1 is available online now.   [Click]
Universiti Malaysia Sabah, Malaysia.
I would like to express my appreciation to all the reviewers and editors, who have been working
very hard to ensure the quality of the journal. It's my honor to work with such a wonderful team.

JOCET 2014 Vol.2(2): 118-121 ISSN: 1793-821X
DOI: 10.7763/JOCET.2014.V2.104

Alkaline Pretreatment of Waste Activated Sludge in Anaerobic Digestion

Watcharapol Wonglertarak and Boonchai Wichitsathian
Abstract—Slow degradation of waste activated sludge (WAS) is a disadvantage of anaerobic digestion leading to high sludge retention time in conventional digesters. So, this study was proposed to increase biodegradability of WAS by alkaline pretreatment, and effect of pretreatment on the performance of anaerobic digestion and treatment efficiency was evaluated under both ambient and thermophilic condition. The soluble chemical oxygen demand (SCOD) and biochemical oxygen demand (BOD) fractions increased when pH values were increased. The solubilization had the highest increase in the pH range of 11 to 12 and gradually increased in the pH range of 8-11. However, the BOD20/COD ratios decreased for adjusted pH 10 and pH 11, and biodegradation was limited at pH 12. And pH 8 was the optimal value this alkaline pretreatment on anaerobic digestion. In alkaline pretreatment thermophilic anaerobic condition (PTAN), the result remove were 42.16%, 43.15% and 50.64% for TS, VS and COD removal, respectively, which are higher efficiency and gas production when compared to other conditions.

Index Terms—Waste activated sludge, alkaline pretreatment, anaerobic digestion, thermophilic.

W. Wonglertarak and B. Wichitsathian are with School of Environmental Engineering, Institute of Engineering, Suranaree University of Technology, Nakhon Ratchasima, Thailand (e-mail:,


Cite:Watcharapol Wonglertarak and Boonchai Wichitsathian, "Alkaline Pretreatment of Waste Activated Sludge in Anaerobic Digestion," Journal of Clean Energy Technologies vol. 2, no. 2, pp. 118-121, 2014.

Copyright © 2008-2022. Journal of Clean Energy Technologies. All rights reserved.