Closing the loop: integrative systems management of waste in food, energy, and water systems

Abstract

Modern food, energy, and water (FEW) systems are the product of technologies, techniques, and policies developed to address the needs of a given sector (e.g., energy or agriculture). Wastes from each sector are typically managed separately, and the production systems underlying FEW have traditionally treated pollution and waste as externalities simply diffused into the ambient environment. Integrative management that optimizes resource use presents opportunities for improving the efficiency of FEW systems. This paper explains how FEW systems can be optimized to (1) repurpose or cycle waste products, (2) internalize traditional externalities, and (3) integrate wastes with resource inputs across systems by diverting waste by-products from one system to meet demands of another. It identifies the means for Bclosing the loop^in production systems. Examples include management of legacy wastes from fossil fuel industries (coal and natural gas) and integrative designs for advanced renewable systems (biogas from waste, bioenergy from CAM plants, and solar). It concludes with a discussion of how studying the governance of such systems can assist in tackling interconnected problems present in FEW systems. New governance arrangements are needed to develop solutions that can align with regulatory frameworks, economics incentive, and policies. Four aspects of governances (property rights, policy design, financing, and scale) emerge as tools to facilitate improved institutional design that stimulates integrative management, technology innovation and deployment, and community development. The conclusion offers a framework through which integrative management of FEW systems can be linked to value chains in closed-loop systems.

Global Trends and Current Status of Commercial Urban Rooftop Farming

“…Furthermore, effluents from anaerobic digestion of biomass can also be used as a fertilizer in hydroponic systems. This technology, however, is still at the pilot stage [34,35].…”

Efficiency of a novel “Food to waste to food” system including anaerobic digestion of food waste and cultivation of vegetables on digestate in a bubble-insulated greenhouse

“…The lack of 'circularity' in the way food production and utilisation is performed is a root cause. In its current state, the flow of energy, materials and water is only weakly coordinated (Davis et al, 2016). A value chain starting with a fossil resource and ending with 'waste' is a linear process.…”

Biomass Residues to Renewable Energy: A Life Cycle Perspective Applied at a Local Scale

“…The general framework (Figure 2), defined by the ISO 14040 and 14044 [12,13], consists of four conceptual phases, namely: Goal and Scope definition, Life Cycle Inventory (LCI), Life Cycle Impact Assessment (LCIA) and Interpretation. LCA is an extremely versatile methodology, useful to investigate different sectors, such as the renewable energy from biomass [6][7][8][9][10], the bio-based industry [14,15], the chemical and pharmaceutical sectors [16,17] and the waste management systems [18]. The simulation was carried out using SimaPro software (version 8.0.…”

“…The use of different logging residues to produce bioenergy was also investigated by Hammar et al [8], taking into account Swedish conditions. Another work outlines the importance of an integrative resources management aimed to close the loop of the production systems, to implement a suitable strategy in line with the regulatory framework [9]. Moreover, Thornely et al [10] emphasized that medium scale district heating boilers, fed by wood chips, lead to the highest GHGs reduction per unit of harvested biomass.…”