Stimulation of Methanogenesis in a Laboratory Scale UASB Reactor Treating Domestic Sewage by Fe(0) Application

• Published in: Environmental technology Vol. 25; no. 5; pp. 613 - 619
• Main Authors: Xu, H., Aiyuk, S., Zhang, Y., Chen, G., Pieters, J., Verstraete, W.
• Format: Journal Article
• Language: English
• Published: London Taylor & Francis Group 01-05-2004; Selper
• Subjects: ANAEROBIC DIGESTION; Applied sciences; Bacteria, Anaerobic; Bioreactors; DOMESTIC SEWAGE; Exact sciences and technology; General purification processes; General treatment and storage processes; IRON; Iron - chemistry; Methane - analysis; METHANOGENESIS; Oxygen - chemistry; Pollution; Sewage - chemistry; UASB; Waste Disposal, Fluid - methods; Wastes; Wastewaters; Water treatment and pollution; Waste treatment; Upflow anaerobic sludge blanket reactor; Laboratory scale; Biogas; Anaerobic digestion; Waste water; Biological purification; Domestic waste water; Bioreactor; Flocculation reagent; Chemical oxygen demand; Flocculation; Methanogenesis; Water quality; Physicochemical purification; Recycling; Biological treatment; Strength
• DOI: 10.1080/09593330.2004.9619351
• EISSN: 1479-487X
• ISSN: 0959-3330; 1479-487X

The effects of application of zero valence Fe (Fe(0)) on the anaerobic digestion of sewage was investigated using two laboratory scale UASB reactors. One reactor had Fe(0) addition in a container found midway along the recycling loop. The other one was a control reactor. In a test run period of 76 days, the Fe(0) application significantly increased the CH
4
yield by 8.7% and decreased the effluent COD concentration by 21.0% relative to the control reactor. A decrease of the H
2
concentration of biogas and the CODs/CODt ratio in effluent by Fe(0) application were observed. The obtained results imply that the methanogenesis and COD removal efficiency of the UASB reactor were stimulated by Fe(0) application. The higher performance of the reactor with Fe(0) application arises from the integrated functions of Fe(0) or its ionic state as donor of H
2
, macronutrient, and flocculant. This study showed that the supply of Fe(0) to a UASB can improve the methanogenesis and the overall COD removal of a UASB reactor treating low-strength domestic waste water.