Biochemical methane potential trial of terrestrial weeds: Evolution of mono digestion and co-digestion on biogas production

• Main Authors: Biswanath Saha, Palem Mohammed Yunus, Meena Khwairakpam, Ajay S. Kalamdhad
• Format: Article
• Language: English
• Published: KeAi Communications Co., Ltd. 2020-01-01
• Series: Materials Science for Energy Technologies
• Subjects: Parthenium hysterophorus; Lantana camara; Ageratum conyzoides; Anaerobic digestion; Biomethane potential; Co-digestion
• Online Access: http://www.sciencedirect.com/science/article/pii/S2589299120300513

Parthenium hysterophorus, Lantana camara and Ageratum conyzoides are considered among the world’s top twenty notorious terrestrial weeds due to their reproduction potential and hazardous nature. They can grow within a few weeks and cover entire agricultural land (Parthenium hysterophorus), forest land (Lantana camara) and native vegetation (Ageratum conyzoides). These terrestrial weeds are difficult to manage as they re-grow miraculously even after being completely obliterated. The availability of Parthenium hysterophorus, Lantana camara and Ageratum conyzoides in abundance make them attractive feedstock for anaerobic digestion process. Anaerobic co-digestion of Parthenium hysterophorus, Lantana camara and Ageratum conyzoides were performed using cow dung as inoculum and food waste as co-substrate and compared with their anaerobic mono-digestion process. The mono-digestion process resulted in lower biogas yield due to the accumulation of toxic inhibitors. Co-digestion studies are essential to balance nutrients and dilute toxic inhibitors. Different food/microorganisms (F/M) ratios (0.5, 1.0, 1.5. 2.0, 2.5 and 3.0) were optimized for the comparison of mono-digestion and co-digestion of Parthenium hysterophorus, Lantana camara and Ageratum conyzoides through 1L biochemical methane potential batch assays. Due to co-digestion with food waste, biogas yields for Parthenium hysterophorus, Lantana camara and Ageratum conyzoides increased by 17.86%, 10.5% and 15.17% respectively. The reactors were scaled up to 20L capacity to evaluate the spike in biogas yield for the weeds through a daily-fed two-stage anaerobic digester and the enhancement of biogas through anaerobic co-digestion process for Parthenium hysterophorus, Lantana camara and Ageratum conyzoides were examined to be 82.9%, 73.3% and 83.01% respectively compared to the mono-digestion process. Operation of a two-stage anaerobic digester showed successful augmentation of biogas production from these noxious terrestrial weeds through the anaerobic co-digestion process with food waste.