Pilot scale investigation and optimization of the moving bed bioreactor (MBBR) as an ammonia removal upgrade technology for lagoon wastewater treatment systems

生物处理是污水除氨最常用、最经济的方法。然而，在寒冷的温度下，硝化率大幅下降或在加拿大的许多处理系统中完全受阻。目前在加拿大有1000多个曝气泻湖处理设施在运行，由于它们暴露的表面积很大，因此在冬季会受到低温的影响。附着式生长工艺，特别是移动床生物膜反应器（MBBR）在低温硝化方面显示出前景；然而，MBBR技术尚未在长时间暴露于1ºC（冬季污水排放泻湖的常见温度）的情况下进行研究或优化。此外，对于长期暴露在极冷温度下的废水处理系统中附着的生物膜和嵌入的微生物群落的反应，存在着基本的知识差距。本研究的目的是研究和优化MBBR技术作为低温下泻湖系统升级处理的性能，并进一步了解极低温下附着生物膜和生物量特性的基本知识。此外，该研究还将研究如何优化MBBR装置在高温和低氨浓度条件下的处理效率和运行成本，以升级MBBR系统，该系统设计用于在极冷温度下氧化高浓度氨。此外，该研究将使用数字粒度分析来表征硝化升级MBBR处理系统中的固体。下一代基因测序、环境扫描电镜和共聚焦激光扫描显微镜结合活/死活力染色和荧光原位杂交将用于研究温度、负载和生物载体几何形状对附着在MBBR载体上的生物膜和生物量的影响。最终，这些进展将通过减少有害有害物质的排放，帮助减少对环境、渔业资源和人类健康的风险。

Biological treatment is the most common and economical means of ammonia removal in wastewater. However, at cold temperatures nitrification rates decline substantially or become completely impeded in many treatment systems in Canada. Over 1000 aerated lagoon treatment facilities are presently in operation in Canada and due to their large exposed surface areas are subject to low temperatures in the winter. Attached growth processes and specifically the moving bed biofilm reactor (MBBR) has shown promise with respect to low temperature nitrification; however, the MBBR technology has not been studied nor optimized during long exposures to 1ºC, a common temperature of wastewater exiting lagoons during winter months. Furthermore, a fundamental gap in knowledge exists with respect to the response of attached biofilm and embedded microbial communities in wastewater treatment systems exposed to very cold temperatures for long durations. The objective of this research is to investigate and optimize the performance of the MBBR technology as an upgrade treatment for lagoon systems at cold temperatures and further develop a fundamental understanding of attached growth biofilm and biomass characteristics at very cold temperatures. In addition, the study will investigate methods to optimize the treatment efficiency and operational costs of MBBR units during warm temperature and low ammonia concentration conditions in upgrade MBBR systems designed to oxidize high ammonia concentrations at very cold temperatures. Furthermore, the study will characterize the solids exiting the nitrifying upgrade MBBR treatment systems using digital particle size analysis. Next generation genetic sequencing, environmental scanning electron microscopy and confocal laser scanning microscopy in combination with live/dead viability staining and fluorescent in-situ hybridization will be used to investigate the effects of temperature, loading and biocarrier geometry on the biofilm and biomass attached to the MBBR carriers. Ultimately theses advances will help reduce the risks to the environment, fisheries resources, and human health by decreasing the discharge of harmful deleterious substances.