Zero Valent Iron Significantly Enhances Methane Production from Waste Activated Sludge by Improving Biochemical Methane Potential Rather Than Hydrolysis Rate

Biochemical methane potential (BMP) tests have been carried out to determine the anaerobic digestibility of the waste activated sludge (WAS) and the sludge pretreated by NaOH (PWAS). The optimal NaOH dosage was determined to be 45 meq NaOH/L. The maximum SCOD solubilization was 27.7, 31.4 and 38.3% at the temperatures of 25, 35 and 55°C respectively after 4 hours reaction. The final methane yield of simulated food waste (SFW) was 430 ml CH4/g VSadded, and those of PWAS (25°C), PWAS (35°C) and PWAS (55°C) was 274, 286 and 310 ml CH4/g VSadded respectively after 20 days. The figures were 66%, 73% and 88% higher than that of WAS. The methane production in anaerobic co-digestion is considerably affected by the fraction of SFW and PWAS in the feed. The anaerobic digestibility of the feed mixture (SFW with PWAS) is higher than that of the feed mixture (SFW with WAS). Anaerobic co-digestion of food waste with the PWAS is found to be an attractive option to reduce the solid waste volume with improved methane recovery.

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Comment on “Parameter Identification and Modeling of the Biochemical Methane Potential of Waste Activated Sludge”(1)

Environmental Science & Technology ◽

10.1021/es201803j ◽

2011 ◽

Vol 45 (17) ◽

pp. 7596-7597 ◽

Cited By ~ 1

Author(s):

D.J. Batstone ◽

S.G. Pavlostathis ◽

P.D. Jensen ◽

I. Angelidaki

Keyword(s):

Activated Sludge ◽

Parameter Identification ◽

Waste Activated Sludge ◽

Biochemical Methane Potential ◽

Methane Potential

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Pre-treatment of thickened waste activated sludge (TWAS) for enhanced biogas production via the application of a novel radial horn sonication technology

Water Science & Technology ◽

10.2166/wst.2017.069 ◽

2017 ◽

Vol 75 (9) ◽

pp. 2179-2193 ◽

Cited By ~ 5

Author(s):

Sri Suhartini ◽

Lynsey Melville ◽

Tony Amato

Keyword(s):

Activated Sludge ◽

Biogas Production ◽

Applied Pressure ◽

Low Frequency ◽

Waste Activated Sludge ◽

Biochemical Methane Potential ◽

Experimental Conditions ◽

Working Volume ◽

Methane Potential ◽

Pre Treatment

The efficacy of sonication as a pre-treatment to anaerobic digestion (AD) was assessed using thickened waste activated sludge (TWAS). Efficiency was measured in relation to solubilisation, dewaterability, and AD performance. Eighteen experimental conditions were evaluated at low frequency (20 kHz), duration (2–10 s), amplitude (∼8–12 μm) and applied pressure (0.5–3.0 barg), using a sonix™ patented titanium sonoprobe capable of delivering an instantaneous power of ∼6 kW provided by Doosan Enpure Ltd (DEL). An optimised experimental protocol was used as a pre-treatment for biochemical methane potential (BMP) testing and semi-continuous trials. Four digesters, with a 2-L working volume were operated mesophilically (37 ± 0.5 °C) over 22 days. The results showed that the sonix™ technology delivers effective sonication at very short retention times compared to conventional system. Results demonstrate that the technology effectively disrupts the floc structures and filaments within the TWAS, causing an increase in solubilisation and fine readily digestible material. Both BMP tests and semi-continuous trials demonstrated that sonicated TWAS gave higher biodegradability and methane potential compared to untreated TWAS. Partial-stream sonication (30:70 sonicated to untreated TWAS) resulted in a proportionate increase in biogas production illustrating the benefits of full-stream sonication.

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