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ARS Home » Southeast Area » Athens, Georgia » U.S. National Poultry Research Center » Quality and Safety Assessment Research Unit » Research » Publications at this Location » Publication #426230
Research Project: Smart Optical Sensing of Food Hazards and Elimination of Non-Nitrofurazone Semicarbazide in Poultry

Location: Quality and Safety Assessment Research Unit

Title: Effect of biochar on methane production and odor reduction during anaerobic digestion of DAF solids collected from poultry slaughterhouse facility in Alabama

Author
item FARAHMANDZAD, NAVID - Auburn University
item SHANMUGAM, SARAVANAN - Auburn University
item HIGGINS, BRENDAN - Auburn University

Submitted to: ASABE Annual International Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 7/28/2024
Publication Date: 7/28/2024
Citation: Farahmandzad, N.2, S. Shanmugam, B.T. Higgins. 2024. “Effect of Biochar on Methane production and Odor Reduction During Anaerobic Digestion of DAF solids collected from Poultry Slaughterhouse Facility in Alabama.” Annual International Meeting of the ASABE. Anaheim, CA. July 28-31

Interpretive Summary:

Technical Abstract: Throughout the poultry processing cycle, a significant amount of wastewater containing proteins and fats is generated. Dissolved Air Flotation (DAF) is the commonly utilized method for separating solid components (fats and proteins) from this wastewater. The resulting DAF solids, originating from poultry slaughterhouses, consist of approximately 50-60% lipids and 15-25% proteins on a dry matter basis. Currently, these DAF solids, found across the U.S. and including Alabama, are applied to land, causing nuisance odors in the community, and acting as a potential vector for pathogens. To harness the energy potential of DAF solids, semi-continuous reactors have been designed to demonstrate the viability of generating methane through anaerobic digestion (AD). To increase methane production and reduce pH drop after DAF addition, inoculum has been adapted to DAF solid samples. However, a significant challenge in the AD process is the emission of highly malodorous compounds, leading to community resistance against the installation of anaerobic digesters for treating poultry-derived waste (DAF solids). Analysis using headspace-gas chromatography-mass spectrometry (HS-GC-MS) revealed the presence of malodorous compounds, including sulfur-based compounds, indole, methanethiol, methylamine, and odorous acids such as acetic acid, butyric acid, and propionic acid in samples following the AD of DAF solids. These compounds not only generate an unbearable odor posing health risks to humans but also compromise biomethane purity, hindering biomethane production. Therefore, alongside biogas assessment, it is crucial to address odor mitigation during the anaerobic digestion of DAF solids. However, there is a lack of literature on odor abatement in anaerobic digestion processes. Previous studies have indicated that conductive materials like biochar can increase methane production by enhancing the activity of methanogens. The main objective of this study is to explore the potential of pine wood biochar, generated through the pyrolysis of waste pine wood at 450' and 550' under low oxygen conditions, to mitigate odor in AD and increase methane production. This investigation focuses on two primary aspects: first, the examination of two types of pine wood biochar (450-550') in reducing odor during AD as measured using HS-GC-MS, and second, the evaluation of biochar's impact on enhancing methane production and purity in the final biogas. Additionally, ion chromatography will be performed to assess the effect of the noted biochars on the anion and cation profile, indicating the nutritional value of digestate that can be utilized as agricultural compost or nutrients for algae cultivation.