2 research outputs found
Upcycling of Spent Tea Leaves and Spent Coffee Grounds into Sustainable 3D-Printing Materials: Natural Plasticization and Low-Energy Fabrication
Food processing byproducts are potential filling materials
for
fabricating sustainable composites with broad applications. We herein
report the use of spent coffee grounds (SCG) and spent tea leaves
(STL) to prepare biomass/poly(lactic acid) (PLA) composites as novel
3D-printing inks. The results show that the 3D-printability can be
upheld at a high biomass loading of 40 wt %. As for strength performance,
the biomass addition disrupted the PLA structure and reduced the tensile
strength of the 3D-printed specimens. However, elongation at break
was enhanced 5-fold at 20 wt % SCG, which could be attributed to the
plasticizing effect of the naturally occurring oil in SCG. The SCG
oil can be added to STL/PLA for improved ductility. With little oil
(<30 mg/g composite) at ∼20 wt % biomass loading, samples
prepared from 155 °C-filament showed higher tensile strength
than those at 185 °C. Microscopic imaging evidenced more significant
pore formation in the latter, rendering the structure delicate. These
findings reveal the complex effects of filler properties on the biomass-PLA
interface that determines the composite performance
Recovery of phosphorus from wastewater: A review based on current phosphorous removal technologies
Phosphorus (P) as an essential nutrient for life sustains the productivity of food systems; yet misdirected P often accumulates in wastewater and triggers water eutrophication if not properly treated. Although technologies have been developed to remove P, little attention has been paid to the recovery of P from wastewater. This work provides a comprehensive review of the state-of-the-art P removal technologies in the science of wastewater treatment. Our analyses focus on the mechanisms, removal efficiencies, and recovery potential of four typical water and wastewater treatment processes including precipitation, biological treatment, membrane separation, and adsorption. The design principles, feasibility, operation parameters, and pros & cons of these technologies are analyzed and compared. Perspectives and future research of P removal and recovery are also proposed in the context of paradigm shift to sustainable water treatment technology. P removal efficiencies and P recovery potential of four typical wastewater treatment processes are critically reviewed. Feasibility, transfer routes, operation parameters, and pros & cons of these technologies in P recovery are analyzed and compared P can be recovered from wastewater into value-added fertilizers or soil amendment. Perspectives and future research directions of P removal and recovery are outlined.</p