Impact of trace element additives on anaerobic digestion of sewage sludge with in-situ carbon dioxide sequestration

• Published in: Process biochemistry (1991) Vol. 51; no. 9; pp. 1283 - 1289
• Main Authors: Linville, Jessica L., Shen, Yanwen, Schoene, Robin P., Nguyen, Maximilian, Urgun-Demirtas, Meltem, Snyder, Seth W.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Ltd 01.09.2016
• Subjects: Anaerobic digestion; Carbon dioxide sequestration; INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; Olivine; Renewable methane production; Trace elements; Olivine; Carbon dioxide sequestration; Trace elements; Renewable methane production; Anaerobic digestion
• ISSN: 1359-5113; 1873-3298
• DOI: 10.1016/j.procbio.2016.06.003

[Display omitted] •Evaluated trace element addition during anaerobic digestion of sewage sludge.•Olivine was used for in-situ CO2 sequestration to produce renewable methane.•Olivine and 1.5mg/L Ni and Co addition increased the methanation kinetics by 6–56%.•Lab bench tests achieved up to 56% increase in methane yield.•Simultaneously, lab bench tests resulted in up to 17.3% increase in methane volume. Anaerobic digestion (AD) of sludge at wastewater treatment plants can benefit from addition of essential trace metals such as iron, nickel and cobalt to increase biogas production for utilization in combined heat and power systems, fed into natural gas pipelines or as a vehicle fuel. This study evaluated the impact and benefits of Ni/Co and olivine addition to the digester at mesophilic temperatures. These additions supplement previously reported research in which iron-rich olivine (MgSiO4) was added to sequester CO2 in-situ during batch AD of sludge. Trace element addition has been shown to stimulate and stabilize biogas production and have a synergistic effect on the mineral carbonation process. AD with 5% w/v olivine and 1.5mg/L Ni/Co addition had a 17.3% increase in methane volume, a 6% increase in initial exponential methane production rate and a 56% increase in methane yield (mL CH4/g CODdegraded) compared to the control due to synergistic trace element and olivine addition while maintaining 17.7% CO2 sequestration from olivine addition. Both first-order kinetic modeling and response surface methodology modeling confirmed the combined benefit of the trace elements and olivine addition. These results were significantly higher than previously reported results with olivine addition alone [1] (Linville et al., 2016).