INFEWS/T2: NEWIR Manure: Nutrients, Energy, and Water Innovations for Resource Recovery

“NEWIR肥料”是一项多学科合作项目，涉及内华达大学里诺分校、佛罗里达大学、加州州立大学奇科分校和马德里自治大学（西班牙）。该项目解决了现代农业的一个挑战：大规模集中动物饲养作业（cafo）的可持续粪便管理，它需要工程师、社会科学家和动物营养科学家之间的重要互动。cafo的增长使乳制品和肉类的产量增加，但它也产生了与粪便处理和管理相关的重大环境影响。一个主要问题是地下水和地表水供应的污染，这对内华达州和加利福尼亚州等干旱地区至关重要。该团队正在开发一项新技术，利用新型的热化学和生物转化技术，从粪便中回收营养物质，制成以藻类为基础的牛饲料。这项技术可以同时回收和利用能量来产生热量和电力。饲料产品的质量将在人工瘤胃系统中进行评价。该技术将通过生命周期评估（LCA）进行分析，以更好地了解环境影响，并通过经济分析考虑改善环境绩效带来的社会效益。该项目将通过加州州立大学奇科分校（主要是本科生，为西班牙裔服务的机构）的学生在内华达大学里诺分校学习的REU，国际学者交流，以及五名博士生的直接培训和指导，培养多元化的未来STEM劳动力。在NEWIR创新中，粪便通过水热碳化（HTC）处理。在选定的金属氧化物存在的情况下，磷和氮被选择性地分割成水相，以及显著的有机含量。碳以炭的形式被留下，可以通过气化和后续发电转化为热能和电力。藻类可以在HTC的水产物中生长，利用有机成分和营养成分。两种被广泛研究的异养微藻菌株，小球藻和莱茵衣藻，以及著名的膳食补充剂蓝绿藻菌株最大螺旋藻，将被评估。藻类可作为高价值、营养丰富的牛饲料添加剂，可与低成本的作物残茬（如玉米秸秆）混合，以提供营养饲料。动物科学家将通过完善的体外双流连续培养系统评估饲料的营养利用率和消化率。水被回收用于微藻生长，未回收的水将通过直接接触膜蒸馏净化，用于现场卫生和消毒。与传统粪肥管理做法相比，LCA将被应用于评估NEWIR过程中综合资源回收的环境影响，并通过减少关键生命周期影响（例如碳足迹、富营养化、水资源枯竭和体现能源）来预期效益。将根据工程、原料、动物营养、生命周期成本分析和监管要求进行经济分析，以深入了解生产商和决策者面临的障碍和机遇。该项目有潜力通过将废物转化为资产，同时减少对环境的影响，提高大型cafo的可持续性。采用新生态环境评估流程可以显著减少乳制品和牛饲料业务的环境足迹，从而使周边社区受益，并提高粮食生产能力。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

"NEWIR Manure" is a collaborative, multidisciplinary project involving the University of Nevada at Reno, the University of Florida, California State University, Chico, and Universidad Autonoma de Madrid (Spain). The project addresses a challenge of modern agriculture: sustainable manure management at large-scale concentrated animal feeding operations (CAFOs), and it requires significant interaction between engineers, social scientists, and animal nutrition scientists. The growth of CAFOs has enabled greater production of dairy products and meat, but it has also generated significant environmental impacts associated with manure disposal and management. A major concern is the pollution of ground and surface water supplies that are critical in arid regions such as Nevada and California. The team is developing a new technology to recover nutrients from manure using novel thermochemical and biological conversions to an algae-based cattle feed. The technology simultaneously recovers and exploits energy to generate heat and power. The quality of the feed product will be evaluated in an artificial rumen system. The technology will be analyzed by life cycle assessment (LCA), to better understand environmental impacts, and by economic analysis that considers the societal benefits from improved environmental performance. The project will train a diverse future STEM workforce through an REU for students at California State University, Chico (a predominantly undergraduate, Hispanic-serving institution) to study at the University of Nevada at Reno, an international scholar exchange, and the direct training and mentoring of five Ph.D. students. In the NEWIR innovation, manure is processed by hydrothermal carbonization (HTC). In the presence of selected metal oxides, phosphorous and nitrogen are selectively partitioned to an aqueous phase, along with significant organic content. Carbon is left behind as a char that can be converted to heat and power by gasification and subsequent generation. Algae can be grown in the aqueous product of HTC, making use of the organic content and nutrients. Two well-studied heterotrophic microalgae strains, Chlorella vulgaris and Chlamydomonas reinhardtti, along with the well-known dietary supplement blue-green algae strain Spirulina maxima, will be evaluated. The algae serve as a high-value, nutrient-dense feed additive for cattle that can be blended with low-cost crop residues (e.g., corn stover) to provide a nutritious feed. Animal scientists will evaluate the feed via a well-established in vitro dual-flow continuous culture system for nutrient utilization and digestibility. Water is recycled for microalgae growth, and non- recovered water will be purified via direct contact membrane distillation for onsite reuse in sanitation and sterilization. LCA will be applied to evaluate environmental impacts of integrated resource recovery from the NEWIR process compared to conventional manure management practices, and benefits are anticipated through reduction of key life cycle impacts (e.g., carbon footprint, eutrophication, water depletion, and embodied energy). An economic analysis will be performed based on engineering, feedstock, animal nutrition, lifecycle cost analyses, and regulatory requirements to provide insight into the obstacles and opportunities facing producers and policy makers. This project has the potential to improve the sustainability of large CAFOs by turning waste products into assets while reducing environmental impacts. Adoption of the NEWIR process could significantly reduce the environmental footprint of dairy and cattle feed operations, with resulting benefits to surrounding communities and increased food production capacity.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.