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

“NEWIR粪便”是内华达大学雷诺分校、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)共同参与的一个多学科合作项目。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学家之间的重大互动。CAFO的增长使乳制品和肉类的产量得以增加，但它也产生了与粪便处理和管理相关的重大环境影响。一个主要的担忧是地下水和地表水供应的污染，这在内华达州和加利福尼亚州等干旱地区是至关重要的。该团队正在开发一种新技术，通过将新型热化学和生物转化为藻类牛饲料，从粪便中回收营养物质。这项技术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定。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，并通过考虑改善环境绩效的社会效益的经济分析进行分析。该项目将通过REU为加州州立大学CHICO(一所以本科生为主的拉美裔服务机构)的学生培养多样化的未来STEM劳动力，以在国际学者交流机构内华达大学里诺分校学习，并直接培训和指导五名博士生。在NEWIR的创新中，粪便通过水热碳化(HTC)进行处理。在选定的金属氧化物存在下，磷和氮被选择性地分配到水相中，以及大量的有机含量。碳被留下来作为一种焦炭，可以通过气化和随后的发电转换为热量和电力。利用HTC的有机含量和营养物质，可以在HTC的水产品中生长藻类。两个研究得很好的异养微藻菌株，普通小球藻和莱茵衣藻，以及著名的膳食补充剂蓝藻菌株极大螺旋藻将被评估。这些藻类是牛的一种高价值、营养密集的饲料添加剂，可以与低成本的作物残渣(如玉米秸秆)混合，提供有营养的饲料。动物科学家将通过建立完善的体外双流连续培养系统来评估饲料的营养利用和消化率。水被循环用于微藻生长，未回收的水将通过直接接触膜蒸馏进行净化，用于现场卫生和杀菌。LCA将被应用于评估从NEWIR过程中综合资源回收与传统粪便管理实践相比的环境影响，并通过减少关键的生命周期影响(例如，碳足迹、富营养化、水消耗和体现能量)来预期收益。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，以洞察生产者和政策制定者面临的障碍和机会。该项目有可能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NEWIR流程可以显著减少乳制品和牛饲料作业的环境足迹，从而为周围社区带来好处，并提高食品生产能力。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势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.