I-Corps: Vacuum Stripping and Absorption to Recover Ammonia from Wastewater

这个I-Corps项目的更广泛影响是开发技术，降低处理富氨废水的运营成本，并通过将去除的氨转化为可销售的氮肥来创收。 城市污水处理设施中厌氧消化系统的数量不断增加，集中的动物饲养操作正在将污水处理的范式从污染物去除转变为以沼气、营养物和水的形式回收生物能。该技术可以以不同尺寸的模块制造，提供操作的简易性和缩放的灵活性。从废水中提取的氨也有可能用于生产认证的有机肥料。I-Corps的这个项目是基于真空汽提和吸收（VaSA）技术的开发，用于回收高纯度废水中的氨。VaSA将真空热汽提和酸吸收结合起来，从富氨废水中抽出氨，形成硫酸铵颗粒。此外，回收废水中的氨可能是能源密集型的哈伯-博世氨合成工艺的可持续替代方案。使用弱真空，沸点从100降低到65摄氏度，安全，有效地汽提氨，而无需预处理。它已被公认为最实用的氨回收方法，填补了高效、通用和可扩展的氨回收技术的差距。当VaSA被纳入厌氧消化系统时，它避免了氨对产甲烷微生物的抑制，从而能够在更高的负荷率下实现稳定的厌氧消化。VaSA工艺中的真空辅助低温热处理增强了固体溶解和生物降解性，进一步增加了甲烷产量，因为汽提后的生物降解物返回到消化器中。当采用VaSA从沼气池流出物中回收氨时，它提高了从沼气池流出物中分离固体的能力，并将B类生物固体升级为A类，适用于不受限制的土地应用。该奖项反映了NSF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。

The broader impact of this I-Corps project is the development of technology that lowers the operating costs for treatment of ammonia-rich wastewater and generates revenues by turning the removed ammonia into a sellable nitrogen fertilizer. The ever-increasing number of anaerobic digestion systems at municipal wastewater treatment facilities and concentrated animal feeding operations are shifting the paradigm of wastewater treatment from contaminant removal to recovery of bioenergy in the form of biogas, nutrients, and water. The technology may be fabricated in different sizes of modules, providing operational ease and flexibility of scaling. The ammonia extracted from wastewater also has the potential to be used for production of certified organic fertilizers. This I-Corps project is based on the development of technology termed vacuum stripping and absorption (VaSA) for recovering ammonia in wastewater with high purity. VaSA couples vacuum thermal stripping and acid absorption to pull ammonia out of ammonia-rich wastewater to form ammonium sulfate granules. Moreover, recovering ammonia in wastewater may be a sustainable alternative to the energy-intensive Haber-Bosch process for ammonia synthesis. Using a weak vacuum, the boiling point is reduced from 100 to 65 degrees C for safe, efficient stripping of ammonia without the need for pretreatment. It has been recognized as the most practical method for ammonia recovery and fills the gap for an efficient, versatile, and scalable ammonia recovery technology. When VaSA is incorporated into anaerobic digestion systems, it avoids ammonia inhibition to methane-producing microorganisms, thus enabling stable anaerobic digestion at a higher loading rate. The vacuum-assisted low-temperature thermal treatment in the VaSA process enhances solids solubilization and biodegradability of digestate, further increasing methane production as stripped digestate is returned to the digesters. When employing VaSA to recover ammonia from digester effluent, it improves the ability to separate solids from digester effluent and upgrades the from Class B biosolids to Class A for unrestricted land application.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.