Development of anammox and anoxic-aerobic granular biomass for advanced wastewater treatment at low temperatures

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Wastewater treatment plants in Canada are under regulatory pressure to upgrade to nitrogen and phosphorus removal with minimized capital cost and within existing infrastructure. There is additional stress to lower operational costs by achieving energy independence and decreasing carbon footprint. Two new processes that can facilitate these goals are subject of the proposed research: main stream partial nitrification/anammox (PN/A) and anoxic-aerobic granular sludge (AGS). ***Application of the PN/A process to treat municipal sewage, which has low temperature and low ammonia concentration with large dilute spring flows, is proposed. The process is particularly applicable to plants with anaerobic sludge digesters where sludge dewatering sidestream (high temperature, high ammonia, low flow) is already treated in a well-established PN/A process, such as in Guelph ON or planned Winnipeg North plant. Early full scale mainstream PN/A process experiments in EU confirmed potential of the process for significant energy and chemical savings but revealed significant unsolved problems with consistent granulation and process stability. This research (2 PhD and 2 BSc students) will focus on improvement of granular PN/A biomass and biofilm formation in low temperature and ammonia environments to tailor the process to conditions of municipal wastewater treatment, and will take place at the Winnipeg North plant, where high concentration warm sidestream is generated along with municipal wastewater. Biodiversity will be compared between the granules and biofilm in hybrid systems with attached and suspended biomasses leading to criteria for process optimization under variable conditions. Bio-augmentation from side- to main-stream PN/A will be quantified.***The AGS process developed in EU is used in a proprietary sequencing batch reactor mode, treating mainstream at some 40% reduction of capital costs, land requirements and energy use. Being proprietary, there are no design guidelines available to Canadian consultants amidst reports of prolonged start-up problems and degranulation in existing installations. The AGS process has never been used in continuous flow. As Canadian plants are mostly continuous flow the research aims to develop a continuous flow AGS process. Two PhD and 3 BSc students will focus on beneficial stressors inducing granulation in continuous mode as well as developing standard procedures for biofilm formation potential and biofilm strength. Further, standard design parameters will be evaluated and communicated to stakeholders in order to encourage the proliferation of AGS in N. America. The work will be conducted at the Winnipeg West plant and the planned Aerobic Granular Sludge Facility at Rock River IL plant. ***Engineering consultants and municipalities are eagerly waiting for results which should facilitate the use of these two paradigm-changing technologies in Canada. ********