INFEWS/T3: Closing the Loop: An Integrated, Tunable, and Sustainable Management System for Improved Energy, Nutrient, and Water Recovery from Biowastes

磷是一种元素，与氮和钾一起，使美国和全球的粮食产量大幅增加。磷是从天然矿藏中开采出来的，但这些矿藏正在减少。当代报告表明，随着全球供应减少和粮食需求增加，磷危机悬而未决。目前，磷作为肥料的利用是能源密集型和昂贵的。磷的供应有限，从食物和其他废物和水体中回收的磷几乎是不存在的。传统上，农业生产一直是最优化的，很少或根本不考虑磷的损失，而不是将其用于生产作物。这种做法导致化肥生产和处理农业径流中的磷废物以及食物和动物废物需要大量能源。这个问题的另一个方面是，一些用于农业领域的磷流失到湖泊和河流中，造成了相当大的环境破坏。这些磷问题严重影响了我们的食物、能源和水(少数)系统。实现可持续磷管理的两个关键途径是更有效地利用磷进行植物生长的农业施肥系统和从食物和动物粪便以及受污染水中的生物废物中回收磷的系统。不幸的是，由于技术限制以及经济和基础设施的限制，我们没有合适的恢复系统。该项目旨在发展一种综合和可持续的管理结构，能够同时应对生物废物管理和农业施肥系统方面的主要技术挑战。这种管理结构将能够回收磷、能源和水，从而提高资源利用效率，并为农业粮食生产提供新的磷来源。该项目集成了多个领域的新技术，包括水热处理、厌氧消化、膜蒸馏、鸟粪石生产和磁性纳米颗粒分离，以收集和回收更多的磷作为鸟粪石。正在对各种系统进行分析和优化，以适应一些废物流设置，以减少总的能源投入。这种方法提供了许多好处，如减少废物体积，净化病原体，以及生产清洁的水、能源和缓释肥料。该方法也足够灵活，可以适应不同的生物垃圾原料，可以调整以生产不同的可循环营养、能量和水产品，以低资源和能源投入实现可持续发展，并可扩展以满足不同级别的管理需求。该系统正在进行实验室规模的开发和测试，并已升级到原型水平，并通过系统建模进行了优化。在盆栽温室试验和田间试验中，正在通过种植玉米、大豆和小麦来评估所生产的鸟粪石肥料的作物利用效率和土壤保持能力。为了确定这些废物和肥料综合管理技术的成本和效益，研究人员正在对从各种废流中去除并回收用于农业应用的磷进行生命周期评估(LCA)。这一分析包括对磷回收和再循环效率的评估，对系统的总体能量平衡的检查，对系统的成本估计，以及对系统的环境评估。该项目正在将学生和博士后研究人员培训与本科教育结合起来，并在代表性不足的群体中促进STEM研究，以及关于促进可持续社区的综合方法的K-12教育。最后，该项目正在向包括学术界和公共部门在内的广泛受众宣传“在少数联系中实现可持续发展”的意识、知识和实践。

Phosphorus is an element that, along with nitrogen and potassium, has enabled large increases in food production in the U.S. and globally. Phosphorus is mined from natural deposits, but these deposits are diminishing. Contemporary reports indicate that there is a pending phosphorus crisis, as global supplies dwindle and demand for food increases. Currently, the utilization of phosphorus for fertilizer is energy intensive and expensive. Phosphorus supply is limited, and its recovery from food and other wastes and water bodies is virtually non-existent. Traditionally, agricultural production has been optimized with little or no consideration of the losses of phosphorus beyond its use in producing crops. This practice leads to large energy needs for fertilizer production and for treatment of phosphorus waste in agricultural run-off, and food and animal wastes. The other side to this problem is that some phosphorus applied to agricultural fields is lost to lakes and rivers causing considerable environmental damage. These phosphorus issues significantly influence our food, energy, and water (FEW) systems. Two key approaches to achieve sustainable phosphorus management are agriculture fertilization systems that more efficiently use phosphorous for plant growth and systems that recover phosphorus from food and animal wastes and from biowastes in contaminated water. Unfortunately, we do not have suitable recovery systems due to technological limitations and economic and infrastructure constraints. This project aims to develop an integrated and sustainable management structure that can simultaneously address the major technical challenges in biowaste management and agriculture fertilization systems. This management structure will enable recovery of phosphorous, energy, and water, thus increasing resource use efficiency and providing a new source of phosphorus for agricultural food production. This project integrates novel technologies in multiple fields, including hydrothermal treatment, anaerobic digestion, membrane distillation, struvite production, and magnetic nanoparticle separation to collect and recycle more phosphorous as struvite. The various systems are being analyzed and optimized to fit a number of waste-stream settings in order to reduce overall energy input. This approach offers many benefits such as reduced waste volume, decontamination of pathogens, as well as the production of clean water, energy, and slow release fertilizers. The method is also sufficiently flexible to accommodate different biowaste feedstocks and tunable to produce different recycled nutrient, energy, and water products, sustainable with low resource and energy input, and scalable to suit different levels of management needs. This system is being developed and tested at bench scale, up-scaled to prototype level, and optimized through systems modeling. Crop utilization efficiency and soil retention of the produced struvite fertilizers are being evaluated by growing corn, soybean, and wheat in both potted greenhouse experiments and in field trials. In order to identify the costs and benefits of these combined waste and fertilization management techniques, the researchers are performing a life cycle assessment (LCA) of the phosphorous removed from the various waste streams and recycled for agricultural applications. This analysis includes an evaluation of the phosphorous recovery and recycling efficiency, examination of the overall energy balance of the systems, a cost estimation of the systems, and an environmental assessment of the system. The project is combining student and postdoctoral researcher training with undergraduate education and promoting STEM research in underrepresented groups and K-12 education on integrated approaches to promote sustainable communities. Finally, the project is promoting awareness, knowledge, and practice of "Sustainability at the FEW Nexus" to a broad range of audiences including both academic and public sectors.