Enhanced Activated Sludge Minimization by Promoting Increased Maintenance Metabolism via Holding Tank Ultrasound Treatment

通过储罐超声波处理促进增加维护代谢，增强活性污泥最小化

• 批准号: 4380-2013
• 负责人: Kennedy, Kevin
• 金额: $ 2.04万
• 依托单位: University of Ottawa
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=655323
• 关键词: Enhanced; Activated; Sludge; Minimization; Promoting

The aerobic activated sludge process (ASP) is the most commonly used technology for biological treatment of municipal carbonaceous wastewaters. While aerobic treatment of municipal wastewater is robust and has been successfully applied at countless treatment facilities around the world its main drawback is the production of large quantities of excess sludge (EXS). On average a conventional ASP produces about 80 kg of dry EXS for every 1000 m3 of wastewater treated, with the EXS being traditionally disposed of by anaerobic digestion followed by land application or landfilling . However, modern capacity restraints and stringent environmental regulations as well as costs make these options unsustainable solutions moving forward. For example, City of Ottawa currently generates 43.6 dry tonnes of EXS per day every day, with the total cost for sludge treatment and disposal being as high as 40-65% of the total operating cost of conventional wastewater treatment plants (Perez-Elvira, et al., 2006). The ideal solution to alleviate both cost and sludge treatment capacity problems would be the direct reduction of EXS within the activated sludge process. The proposed study is unique and blends the benefits and potential synergistic effects of (1) promoting and selecting for lower biomass producing facultative microbes in the ASP via an anaerobic holding tank (HT), and (2) applying high or low intensity ultrasound (US) treatment to a portion of the HT sludge. High intensity US increases cell lysis and solubilisation to promote cryptic growth and lower biomass yields while low intensity US treatment will wound the microbial cells diverting energy to maintenance metabolisms and away from assimilative growth that will also lead to an overall reduction of new biomass sludge. The goal of combining these beneficial systems to reduce excess sludge will be assessed by investigating a novel modified version of the continuous ASP which integrates an anerobic HT with post-sonication treatment in the sludge recycle line prior to recycling back to the ASP aeration basin. Final effluent quality and important residual sludge characteristics such as dewaterability and settleability will be used to assess the quality of the sludge produced by the proposed treatment systems. Additionally, in order to understand the roles of microbial shift, cryptic growth and enhanced maintenance metabolism within the HT + US modified ASP the process will also be monitored at the microbial level at each step (HT, post US, ASP). A combination of microbial viability, activity and stress tests will be used, as well as molecular fingerprinting, population sequencing and scanning electron microscopy to characterize floc morphology will be applied to ultimately characterize microbial ecological changes.

好氧活性污泥法（ASP）是城市含碳废水生物处理最常用的技术。虽然城市废水的好氧处理非常有效，并且已在世界各地无数的处理设施中成功应用，但其主要缺点是产生大量剩余污泥 (EXS)。平均而言，传统 ASP 每处理 1000 立方米废水就会产生约 80 公斤干 EXS，而 EXS 传统上通过厌氧消化进行处理，然后进行土地应用或填埋。然而，现代产能限制、严格的环境法规以及成本使得这些选择成为不可持续的解决方案。例如，渥太华市目前每天产生 43.6 干吨 EXS，污泥处理和处置的总成本高达传统废水处理厂总运营成本的 40-65%（Perez-Elvira 等，2006）。 缓解成本和污泥处理能力问题的理想解决方案是直接减少活性污泥工艺中的 EXS。拟议的研究是独特的，融合了以下优点和潜在的协同效应：(1) 通过厌氧储罐 (HT) 促进和选择 ASP 中产生较低生物量的兼性微生物，以及 (2) 对部分 HT 污泥进行高或低强度超声波 (US) 处理。高强度US处理会增加细胞裂解和溶解，以促进隐性生长并降低生物质产量，而低强度US处理会伤害微生物细胞，将能量转移到维持代谢并远离同化生长，这也将导致新生物质污泥的总体减少。将这些有益系统结合起来以减少剩余污泥的目标将通过研究连续 ASP 的新型改进版本来评估，该版本将厌氧 HT 与污泥回收线中的后超声处理相结合，然后再循环回 ASP 曝气池。最终污水质量和重要的残留污泥特性（例如脱水性和沉降性）将用于评估拟议处理系统产生的污泥的质量。此外，为了了解 HT + US 改良 ASP 中微生物转变、隐性生长和增强的维持代谢的作用，还将在每个步骤的微生物水平上监测该过程（HT、US 后、ASP）。 将结合使用微生物活力、活性和压力测试，以及分子指纹、群体测序和扫描电子显微镜来表征絮体形态，最终表征微生物生态变化。