Converting beach-cast seagrass wrack into biochar: A climate-friendly solution to a coastal problem.
Excessive accumulation of plant 'wrack' on beaches as a result of coastal development and beach modification (e.g. groin installation) is a global problem. This study investigated the potential for converting beach-cast seagrass wrack into biochar as a 'climate-friendly' disposal option for resource managers. Wrack samples from 11 seagrass species around Australia were initially screened for their biochar potential using pyrolysis techniques, and then two species - Posidonia australis and Zostera muelleri - underwent detailed analyses. Both species had high levels of refractory materials and high conversion efficiency (48-57%) of plant carbon into biochar carbon, which is comparable to high-quality terrestrial biochar products. P. australis wrack gave higher biochar yields than Z. muelleri consistent with its higher initial carbon content. According to13C NMR, wrack predominantly comprised carbohydrates, protein, and lignin. Aryl carbon typical of pyrogenic materials dominated the spectrum of the thermally-altered organic materials. Overall, this study provides the first data on the feasibility of generating biochar from seagrass wrack, showing that biocharring offers a promising climate-friendly alternative to disposal of beach wrack in landfill by avoiding a portion of the greenhouse gas emissions that would otherwise occur if wrack was left to decompose.
School of Life and Environmental Sciences, Centre for Integrative Ecology, Deakin University, Victoria 3125, Australia; Climate Change Cluster, University of Technology Sydney, NSW 2007, Australia. Electronic address: p.macreadie@deakin.edu.au.
Peter I
PI
Macreadie
School of Life and Environmental Sciences, Centre for Integrative Ecology, Deakin University, Victoria 3125, Australia; Climate Change Cluster, University of Technology Sydney, NSW 2007, Australia.
Stacey M
SM
Trevathan-Tackett
CSIRO Agriculture and Food, PMB2, Glen Osmond, SA 5064, Australia.
Jeffrey A
JA
Baldock
Climate Change Cluster, University of Technology Sydney, NSW 2007, Australia; Department of Environmental Sciences, Macquarie University, Sydney, NSW 2109, Australia.
Jeffrey J
JJ
Kelleway
Adaptive management; Blue carbon; CO(2); Climate change; Coastal; Emissions