Ceres Smartphone Application

http://deepblue.lib.umich.edu/bitstream/2027.42/106042/1/me589f13section001project13_report.pd

Sensor‐mediated granular sludge reactor for nitrogen removal and reduced aeration demand using a dilute wastewater

A sensor‐mediated strategy was applied to a laboratory‐scale granular sludge reactor (GSR) to demonstrate that energy‐efficient inorganic nitrogen removal is possible with a dilute mainstream wastewater. The GSR was fed a dilute wastewater designed to simulate an A‐stage mainstream anaerobic treatment process. DO, pH, and ammonia/nitrate sensors measured water quality as part of a real‐time control strategy that resulted in low‐energy nitrogen removal. At a low COD (0.2 kg m−3 day−1) and ammonia (0.1 kg‐N m−3 day−1) load, the average degree of ammonia oxidation was 86.2 ± 3.2% and total inorganic nitrogen removal was 56.7 ± 2.9% over the entire reactor operation. Aeration was controlled using a DO setpoint, with and without residual ammonia control. Under both strategies, maintaining a low bulk oxygen level (0.5 mg/L) and alternating aerobic/anoxic cycles resulted in a higher level of nitrite accumulation and supported shortcut inorganic nitrogen removal by suppressing nitrite oxidizing bacteria. Furthermore, coupling a DO setpoint aeration strategy with residual ammonia control resulted in more stable nitritation and improved aeration efficiency. The results show that sensor‐mediated controls, especially coupled with a DO setpoint and residual ammonia controls, are beneficial for maintaining stable aerobic granular sludge.Practitioner pointsTight sensor‐mediated aeration control is need for better PN/A.Low DO intermittent aeration with minimum ammonium residual results in a stable N removal.Low DO aeration results in a stable NOB suppression.Using sensor‐mediated aeration control in a granular sludge reactor reduces aeration cost.Multiple metabolic pathways and competition for nitrite exist in the treatment of anaerobically pretreated mainstream wastewater using a granular sludge reactor.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/155879/1/wer1296_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/155879/2/wer1296.pd

Elucidating the impact of microbial community biodiversity on pharmaceutical biotransformation during wastewater treatment

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/146445/1/mbt212870.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/146445/2/mbt212870_am.pd

Standardizing data reporting in the research community to enhance the utility of open data for SARS-CoV-2 wastewater surveillance

SARS-CoV-2 RNA detection in wastewater is being rapidly developed and adopted as a public health monitoring tool worldwide. With wastewater surveillance programs being implemented across many different scales and by many different stakeholders, it is critical that data collected and shared are accompanied by an appropriate minimal amount of meta-information to enable meaningful interpretation and use of this new information source and intercomparison across datasets. While some databases are being developed for specific surveillance programs locally, regionally, nationally, and internationally, common globally-adopted data standards have not yet been established within the research community. Establishing such standards will require national and international consensus on what meta-information should accompany SARS-CoV-2 wastewater measurements. To establish a recommendation on minimum information to accompany reporting of SARS-CoV-2 occurrence in wastewater for the research community, the United States National Science Foundation (NSF) Research Coordination Network on Wastewater Surveillance for SARS-CoV-2 hosted a workshop in February 2021 with participants from academia, government agencies, private companies, wastewater utilities, public health laboratories, and research institutes. This report presents the primary two outcomes of the workshop: (i) a recommendation on the set of minimum meta-information that is needed to confidently interpret wastewater SARS-CoV-2 data, and (ii) insights from workshop discussions on how to improve standardization of data reporting

Wastewater surveillance for bacterial targets: current challenges and future goals

Wastewater-based epidemiology (WBE) expanded rapidly in response to the COVID-19 pandemic. As the public health emergency has ended, researchers and practitioners are looking to shift the focus of existing wastewater surveillance programs to other targets, including bacteria. Bacterial targets may pose some unique challenges for WBE applications. To explore the current state of the field, the National Science Foundation-funded Research Coordination Network (RCN) on Wastewater Based Epidemiology for SARS-CoV-2 and Emerging Public Health Threats held a workshop in April 2023 to discuss the challenges and needs for wastewater bacterial surveillance. The targets and methods used in existing programs were diverse, with twelve differentdifferentdifferenttargets and nine different methods listed. Discussions during the workshop highlighted the challenges in adapting existing programs and identified research gaps in four key areas: choosing new targets, relating bacterial wastewater data to human disease incidence and prevalence, developing methods, and normalizing results. To help with these challenges and research gaps, the authors identified steps the larger community can take to improve bacteria wastewater surveillance. This includes developing data reporting standards and method optimization and validation for bacterial programs. Additionally, more work is needed to understand shedding patterns for potential bacterial targets to better relate wastewater data to human infections. Wastewater surveillance for bacteria can help provide insight into the underlying prevalence in communities, but much work is needed to establish these methods

Nitrogen and Sulfur Cycling During Wastewater Treatment

Amid the challenges of climate change, aging infrastructure, and urbanization environmental engineers must develop resource efficient water and wastewater treatment. As the population in coastal communities continues to increase and effluent nitrogen regulations become more stringent, innovation in our wastewater treatment infrastructure can help promote resource efficient nitrogen removal. Sea level rise due to global climate change causes seawater intrusion to wastewater collection systems and increases sulfate concentrations in wastewater. When the wastewater collection system is anaerobic, sulfate is biologically converted to sulfide. Sulfide is an electron donor for denitrification, reducing the need for supplemental carbon addition for nitrogen removal. This dissertation presents advancements in our understanding of how sulfur can affect nitrogen cycling during wastewater treatment. The effects of hydrogen sulfide on nitrogen cycling were evaluated in three wastewater treatment systems: two full-scale treatment processes that employ different redox environments, thereby supporting distinct microbial communities, and one lab-scale bioreactor. Studies using microbial communities from the full-scale treatment processes showed that nitrite oxidizing bacteria (NOB) were more sensitive to sulfide than ammonia oxidizing bacteria (AOB). Inhibiting nitrite oxidizing bacteria promotes resource efficient treatment because it can reduce the aeration demands of treatment and support nitrite-based denitrifying metabolisms. However, the extent of inhibition was distinct in the two treatment plants, demonstrating that the effect of sulfide is community specific. Given the potential benefits of sulfide for both denitrification and for inhibiting NOB, the effect of sulfide was tested in a mixed-redox membrane aerated biofilm reactor (MABR). A MABR biofilm is counter-diffusional, meaning the electron donor and electron acceptor diffuse into the biofilm in opposite directions. Accordingly, sulfide is amended in the anoxic bulk liquid, which curtails aerobic oxidation and allows for sulfide oxidation using nitrite or nitrate that was formed in the inner regions of the biofilm as an electron acceptor. Incubation experiments with heavy nitrogen revealed that, consistent with the full-scale systems, sulfide could inhibit NOB but had no impact on the rates of ammonia oxidation. During routine reactor monitoring, inhibition of NOB was not apparent, most likely due to the rapid conversion of nitrite to ammonia. Higher effluent ammonia concentrations observed during operation were attributed to inhibition of AOB instead of nitrite reduction to ammonia. Biofilm modeling was used to elucidate dissimilatory nitrite or nitrate reduction to ammonia (DNRA). Simulation results show that DNRA with sulfide as the electron donor could increase effluent ammonium. The genetic potential for nitrite reduction to ammonia was found in a unique population of denitrifying anaerobic methane oxidizers. These organisms are beneficial in the treatment of effluents from mainstream anaerobic processes as they curtail an important greenhouse gas emission while denitrifying. On the other hand, results show that sulfide inhibits nitrous oxide reduction, leading to higher emissions of nitrous oxide, a greenhouse gas with a global warming potential 300 times higher than carbon dioxide. Overall, studies in the mixed-redox counter-diffusional biofilm enhanced our understanding of how sulfide affects microbial community interactions. The results of this dissertation show that hydrogen sulfide could have beneficial impacts on nitrogen cycling in engineered systems. The effect of hydrogen sulfide is complex because microbial communities are adaptable and sulfide induces feedback effects which change overall microbial community interactions. Ultimately, this knowledge can spur the development of technologies that use hydrogen sulfide to develop resource efficient wastewater treatment technologies.PHDEnvironmental EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttps://deepblue.lib.umich.edu/bitstream/2027.42/145825/1/jesethdv_1.pd

Sulfide alters microbial functional potential in a methane and nitrogen cycling biofilm reactor

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/167111/1/emi15352_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/167111/2/emi15352.pd

Sulfide alters microbial functional potential in a methane and nitrogen cycling biofilm reactor

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/167111/1/emi15352_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/167111/2/emi15352.pd

Integrated Modeling and Lab-Scale Investigations Demonstrate the Impact of Sulfide on a Membrane Aerated Biofilm Reactor

An emerging innovation in the wastewater treatment field is the application of membrane aerated biofilm reactors (MABRs) as low-energy and small-footprint nitrogen removal technologies. MABRs use membranes supplied with oxygen to grow mixed-redox counter-diffusional biofilms that are advantageous for studies of coupled sulfur and nitrogen cycling. We have previously shown that sulfide can induce dissimilatory nitrite reduction to ammonia (DNRA) in an MABR. However, the implications of sulfide-induced DNRA on reactor performance have not been quantified, and the overall performance of a MABR treating sulfide-ladened wastewater has not been evaluated. Here, we assessed the impact of sulfide on nitrogen removal in a MABR using modeling and experimental approaches. Experimentally, influent sulfide was increased stepwise into a methane-fed nitrifying MABR over 420 days, and microsensor profiling was used to quantify sulfide, nitrous oxide, and oxygen fluxes. Moderate increases in sulfide caused effluent ammonium concentrations to double and nitrous oxide emissions to increase a hundred-fold. Potential rates of DNRA were determined by calibrating a biofilm model to experimental data and were found to exceed nitrification rates at even moderate sulfide concentrations. The results described here highlight the importance of considering DNRA in engineered systems, especially when treating moderately sulfide-laden wastewaters

Prospects for Biological Nitrogen Removal from Anaerobic Effluents during Mainstream Wastewater Treatment

Growing interest in the anaerobic treatment of domestic wastewater requires a parallel focus on developing downstream technologies that address nitrogen pollution, especially for treatment systems located in eutrophication-impacted watersheds. Anaerobic effluents contain sulfide and hydrogen sulfide (a corrosive gas), dissolved methane (a potent greenhouse gas), ammonium, and residual organic carbon predominantly in the form of volatile fatty acids. Conventional approaches to nitrogen removal are energy- and chemical-intensive and are not appropriate for application to anaerobic effluents. Innovative, energy efficient nitrogen removal processes are being developed and involve several novel chemotrophic processes. This review provides information about these processes, identifies how to control and retain the most desirable microorganisms, and considers the impact of reactor configuration on performance. Given the complexity of the technologies under development that remove nitrogen from anaerobically treated domestic wastewater, we conclude that computational models can support their development and that sensor-mediated controls are essential to achieving energy efficiency