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: w_watcharapol@hotmail.com,
boonchai@sut.ac.th).
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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.
