Collaborative Research: WERF: GOALI: Bioaugmentation-Enhanced Anammox for Mainstream Nitrogen Removal

Krzmarzick 1705088过量的营养氮（N）是影响环境和公众健康的主要污染物;因此，必须从废水（WW）中去除过量的N。传统的脱氮技术依赖于硝化-反硝化两个微生物过程的顺序。第一步（硝化）涉及铵氧化成硝酸盐。缺点是硝化作用需要大量的能量输入来使水通气。第二步（脱氮）涉及将硝酸盐还原为无害的元素氮气。缺点是硝酸盐还原需要宝贵的化学能，而这些化学能可以更好地用于制造生物燃料，如富含甲烷的沼气。利用厌氧氨氧化（anammox）细菌可以提高营养物脱氮的经济性。厌氧氨氧化将亚硝酸盐和铵转化为元素氮气，而不需要任何曝气或化学能。作为一种技术，厌氧氨氧化必须与部分曝气相结合，以从约一半的铵中形成亚硝酸盐。（部分亚硝化），但该工艺与常规营养物脱氮相比，节省了57%的曝气费用和100%的化学能需求。厌氧氨氧化已成为处理高铵、低有机物WW，例如来自厌氧消化污泥的脱水的污泥液体侧流，其占废水处理厂（WWTP）的N负荷的15-30%。本研究的目的是将厌氧氨氧化应用于污水处理厂主流中70-85%的氮负荷。提出的策略是基于利用高活性厌氧氨氧化污泥培养的富氨侧流与上流式厌氧污泥床（UASB）反应器生物增强另一个UASB处理主流。该反应器将作为一个单级部分亚硝化厌氧氨氧化工艺通过引入亚化学计量的元素氧通过曝气。所提出的工作的智力价值是将富含铵的侧流所体现的高氮负荷的责任转化为主流生物脱氮的资产。关键的科学/工程问题是，是否可以使用生物强化的高度富集厌氧氨氧化污泥，以提高在主流的N-处理过程中，由于异养细菌和低N浓度的竞争，条件是不利于生长和维持厌氧氨氧化。PI将探索一种新的分层部分亚硝化和厌氧氨氧化在微好氧外部和缺氧内部相同的污泥颗粒，分别。通过动力学、代谢和宏基因组/转录组学分析，PI将通过提供生物标志物来定量监测它们所含的厌氧氨氧化细菌，从而确定富集的厌氧氨氧化污泥是否在主流中恶化。 他们还将获得有关微生物种群的组成和功能变化的信息。该项目直接解决了美国国家工程院的重大挑战，即通过开发节能技术来控制过量营养氮进入环境的负荷，从而改善氮循环的管理。 两名博士生将与GOALI合作伙伴在区域废水回收设施工作，以获得工业经验。

Krzmarzick1705088Nutrient nitrogen (N) in excess is a major pollutant affecting the environment and public health; consequently, excess N must be removed from wastewater (WW). Conventional nutrient N-removal technology relies on a sequence of two microbial process known as nitrification-denitrification. The first step (nitrification) involves the oxidation of ammonium to nitrate. The drawback is that nitrification requires a large input of energy to aerate the water. The second step (denitrification) involves the reduction of nitrate to harmless elemental nitrogen gas. The drawback is that valuable chemical energy is required for the nitrate reduction that could be better used to make biofuels such as methane-rich biogas. Improvements in the economy of nutrient N-removal can be achieved with anaerobic ammonia oxidizing (anammox) bacteria. Anammox converts nitrite and ammonium to elemental nitrogen gas without any need for aeration or chemical energy. As a technology anammox must be combined with partial aeration to form nitrite from about half of the ammonium (partial nitritation), but this process saves 57% of the aeration costs and 100% of the chemical energy demand compared to conventional nutrient N-removal.Anammox has become a mature technology for the treatment of high ammonium, low organic matter WW, exemplified by sludge liquor side streams from the dewatering of anaerobically digested sludge, which accounst for 15-30% of the N load at wastewater treatment plants (WWTP). The objective of this research is to apply anammox to the 70-85% of the N-load in the mainstream of a WWTP. The strategy proposed is based on utilizing highly active anammox sludge cultivated on the ammonium rich side stream with an upflow anaerobic sludge blanket (UASB) reactor to bioaugment another UASB treating the mainstream. The reactors will be operated as a single-stage partial-nitritation anammox process by introducing substoichiometric quantities of elemental oxygen via aeration. The intellectual merit of the proposed work is to convert the liability of the high N-loading embodied by the ammonium rich side stream into an asset for biological N-removal for the mainstream. The key scientific/engineering question is whether bioaugmentation of highly enriched anammox sludge can be used to enhance the N-treatment process in the mainstream where conditions are less favorable for growing and sustaining anammox due to competition from heterotrophic bacteria and low N concentrations. The PIs will explore a novel stratification of partial nitritation and anammox in the microaerophilic exterior and anoxic interior of the same sludge particles, respectively. Through kinetic, metabolic and metagenomic/transcriptomic analyses, the PIs will determine whether the enriched anammox sludge deteriorates in mainstream by providing biomarkers to quantitatively monitor the anammox bacteria they contain. They will also obtain information on the shifting composition and function of the microbial population. The project directly addresses the National Academy of Engineering grand challenge of improving the management of the N cycle by developing energy saving technology to control the load of excess nutrient-N into the environment. Two PhD students will be working with the GOALI partner at the regional wastewater reclamation facility to gain industrial experience.