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了一种技术，可以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产生收入。城市污水处理设施和集中饲养动物的厌氧消化系统的数量不断增加，正在将污水处理的范式从污染物去除转变为以沼气、营养物质和水的形式回收生物能源。该技术可以以不同大小的模块制造，提供了操作简单性和伸缩性灵活性。从废水中提取的氨也有可能用于生产经过认证的有机肥料。I-Corps项目是基于真空汽提吸收(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相结合，从富氨废水中提取氨，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摄氏度降低到65摄氏度，安全、有效地汽提氨气，而不需要进行前处理。它被认为是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空白。当VASA被纳入厌氧消化系统时，它避免了氨气对产甲烷微生物的抑制，从而能够以更高的负荷率进行稳定的厌氧消化。VASA工艺中的真空辅助低温热处理提高了沼气的固体增溶和可生物降解性，进一步增加了汽提沼液返回沼气池的甲烷产量。当使用VASA从消化池污水中回收氨时，它提高了从消化池污水中分离固体的能力，并将生物固体从B类升级为A类，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。

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.