Department of Building, School of Design and Environment, National University of Singapore, 4 Architectural Drive, (S) 117566, Singapore.
Department of Building, School of Design and Environment, National University of Singapore, 4 Architectural Drive, (S) 117566, Singapore.
Sci Total Environ. 2018 Apr 1;619-620:419-435. doi: 10.1016/j.scitotenv.2017.11.044. Epub 2017 Nov 29.
Landfilling of food waste due to its low recycling rate is raising serious concerns because of associated soil and water contamination, and emission of methane and other greenhouse gases during the degradation process. This paper explores feasibility of using biochar derived from mixed food waste (FWBC), rice waste (RWBC) and wood waste (mixed wood saw dust, MWBC) as carbon sequestering additive in mortar. RWBC is prepared from boiled plain rice, while FWBC is prepared from combination of rice, meat, and vegetables in fixed proportion. Carbon content in FWBC, RWBC and MWBC were found to be 71%, 66% and 87% by weight respectively. Results show that addition of 1-2wt% of FWBC and RWBC in mortar results in similar mechanical strength as control mix (without biochar). 1wt% of FWBC led to 40% and 35% reduction in water penetration and sorptivity respectively, indicating higher impermeability of mortar. Biochar from mixed wood saw dust performed better in terms of mechanical and permeability properties. Increase in compressive strength and tensile strength by up to 20% was recorded, while depth of water penetration and sorptivity was reduced by about 60% and 38% respectively compared to control. Both FWBC and MWBC were found to act as reinforcement to mortar paste, which resulted in higher ductility than control at failure under flexure. This study suggests that biochar from food waste and mixed wood saw dust has the potential to be successfully deployed as additive in cement mortar, which would also promote waste recycling, and sequester high volume carbon in civil infrastructure.
由于食品垃圾的回收利用率低，其在降解过程中会导致土壤和水污染，并排放甲烷和其他温室气体，因此填埋食品垃圾引起了人们的严重关注。本文探讨了将混合食品垃圾（FWBC）、稻壳（RWBC）和木屑（MWBC）生物炭作为碳封存添加剂应用于水泥砂浆的可行性。RWBC 由煮熟的普通大米制备而成，而 FWBC 由大米、肉和蔬菜按固定比例混合制备而成。FWBC、RWBC 和 MWBC 的碳含量分别为 71%、66%和 87%（按重量计）。结果表明，在水泥砂浆中添加 1-2wt%的 FWBC 和 RWBC 可获得与对照样（无生物炭）相似的力学强度。添加 1wt%的 FWBC 可使水渗透率和吸水性分别降低 40%和 35%，表明水泥砂浆的不透水性更高。混合木屑生物炭在力学和渗透性方面表现更好。与对照样相比，抗压强度和拉伸强度分别提高了 20%，而水渗透率和吸水性分别降低了约 60%和 38%。FWBC 和 MWBC 均被发现可增强水泥砂浆的韧性，使其在弯曲破坏下的延性高于对照样。本研究表明，食品垃圾和混合木屑生物炭作为添加剂成功应用于水泥砂浆具有潜力，这也将促进废物回收利用，并在民用基础设施中封存大量碳。
