School cafeterias are a significant source of food waste and represent an ideal opportunity for diverting food waste from landfills. In this study, cafeteria waste audits were conducted at three Florida schools. Food waste comprised the largest fraction of school cafeteria waste streams, ranging from 47% to 58%, followed by milk, paper products (tissue, milk cartons, pasteboard, paper plates, and cardboard), and plastics (plastic wrap, packaging, and utensils). Metal and glass comprised the smallest fraction of the waste stream. Average total waste generation ranged from 50.5 to 137.6 g·student⁻¹·day⁻¹. The mean generation rates for food waste ranged from 24.7 to 64.9 g·student⁻¹·day⁻¹. The overall average for cafeteria waste generation among all three schools was 102.3 g·student⁻¹·day⁻¹, with food waste alone contributing 52.2 g·student⁻¹·day⁻¹. There are two primary approaches to diverting school food waste from landfills: reduction and recycling. Food waste can be reduced through educating students and staff in order to change behaviors that cause food waste. Food waste can be collected and recycled through composting or anaerobic digestion in order to generate beneficial end products, including soil amendments and bioenergy. Over 75% of the cafeteria waste measured in this study could be recycled in this manner.

Small, municipal wastewater treatment plants (WWTPs) that use aerobic digestion treat approximately 40% of the discharged wastewater in the USA, and yet they are an overlooked source of recoverable P. There are no known reports of small, aerobic WWTPs recovering P through struvite (MgNH₄PO₄·6H₂O) precipitation for repurposing as a mineral fertilizer, even though some large WWTPs with anaerobic digestion are. Four small WWTPs in north Florida, USA, with treatment capacities from 371 to 2650 m³ wastewater d⁻¹ and incoming P loads from 2 to 14 kg d⁻¹ were investigated for their potential to produce struvite from digester filtrates. A chemical equilibrium model was used to predict the feasibility of struvite production and the results compared with actual WWTP filtrate measurements. Filtrates from aerobic digesters were able to form struvite if solution pH was increased by ≤1 pH unit. Depending on the WWTP, P recovery in filtrates through struvite precipitation ranged from 27–57% by mass at pH 8.5, via NaOH additions or air sparging. Increasing filtrate Mg concentrations improved P recovery up to 97%. Based upon these results, small WWTPs using aerobic digestion will be able to lower their P waste output through recovery as struvite fertilizer.

There is a pressing need for sustainable renewable fuels that do not negatively impact food and water resources. Algae have great potential for the production of renewable biofuels but require significant water and fertilizer resources for large-scale production. Municipal solid waste (MSW) landfill leachate (LL) was evaluated as a cultivation medium to reduce both water and elemental fertilizer demands of algae cultivation. Daily growth rate and cell yield of two isolated species of algae (Scenedesmus cf. rubescens and Chlorella cf. ellipsoidea) were cultivated in MSW LL and compared with Bold's Basal Medium (BBM). Results suggest that LL can be used as a nutrient resource and medium for the cultivation of algae biomass. S. cf. rubescens grew well in 100% LL, when pH was regulated, with a mean growth rate and cell yield 91.2% and 92.8% of those observed in BBM, respectively. S. cf. rubescens was more adaptable than C. cf. ellipsoidea to the LL tested. The LL used in this study supported a maximum volumetric productivity of 0.55 g/L/day of S. cf. rubescens biomass. The leachate had sufficient nitrogen to supply 17.8 g/L of algae biomass, but was limited by total phosphorus. Cultivation of algae on LL offsets both water and fertilizer consumption, reducing the environmental footprint and increasing the potential sustainability of algae-based biofuels.

Hibiscus cannabinus (kenaf) is an annual fiber crop grown in warm seasons and known for its remarkable productivity; it has been cultivated worldwide for thousands of years as a fiber source. While every part of the plant can be utilized for some purpose, its primary significance lies in the diverse applications of its cellulosic fiber. Kenaf features a blend of long bast and short core fibers, rendering it suitable for various industrial uses. Initially utilized for cordage and livestock feed, kenaf’s applications have expanded over the last century to encompass its utilization as paper pulp, biocomposites, textiles, biomass energy, seed oil, filtration aids, industrial absorbents, and even as a component of potting medium or as a potential source of medicine. Although traditionally a niche crop, the discovery of its diverse applications positions kenaf for rapid expansion in production in the upcoming decades. This article aims to explore the manifold applications of kenaf, highlighting those with the greatest future potential and discussing those that hold promise for commercial-level application with additional research.