Progress 10/01/12 to 12/31/16
Outputs
Target Audience:This project affected a number of target audiences consisting of students, the professional wastewater engineering community, and the community at large. Under the duration of this grant, Zachary Carroll served as a doctoral research assistant. He was awarded his doctorate degree on December 18, 2016 during the winter commencement ceremony at the University of Wisconsin - Madison. The title of his dissertation was "Pathogen and Surrogate Organism Inactivation in the Anaerobic Digestion of Biosolids - An Analysis of Enumeration Methods, Time/Temperature Relationships, and Other Matrix Effects." This project, and a previously funded and related HATCH project, included funding for an hourly undergraduate student to assist Dr. Carroll with experiments, lab management and data management. These individuals included Niccole Carner (previous HATCH project), Peter Balogun, Joshua Ferraro, and Jacob Hendricks. Represented among these students included a woman in STEM (Ms Carner) and an underrepresented racial minority (Mr Balogun). The research and findings of this work will reach the professional wastewater engineering community through peer-reviewed publications and presentations at professional meetings. The citations for these manuscripts and presentations are presented in other sections of this report. The community at large was provided the opportunity to learn about this work and the beneficial use of biosolids as a soil amendment through a number of citizen science and community programs. The specifics names and dates of these programs are presented in other sections of this report. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?As described in other sections of this report, Zachary Carroll completed his doctoral degree and dissertation based on this work. During that time, he was able to mentor four different undergraduate students on research methods in general and biosolids and surrogate analyses specifically on this and a previously funded and related HATCH project. How have the results been disseminated to communities of interest?Dr. Carroll became a University of Wisconsin STEM Fellow. As part of this program he developed an interactive outreach program titled "Toilets to Tomatoes." This module included descriptions of wastewater treatment processes, a hands-on exercise in flocculation and filtration, visual comparisons of plants grown with biosolids ammendments and those with chemical fertilizers, and more. The events where this program was presented are detailed below. UW Family Gardening Day May 7, 2016 May 9, 2015 UW Science Expeditions April 2, 2016 March 22, 2015 March 21, 2015 Randall Elementary School Super Science Saturday April 11, 2015 What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
There are currently no specific regulations for the inactivation of pathogens in thermophilic anaerobic digestion systems (typically operated at 53-56°C). These systems instead fall under general time/temperature regulations. Previous research has indicated that pathogens may be inactivated more rapidly in anaerobic digestion processes compared to other general time/temperature processes. Free ammonia and other matrix effects may influence organism inactivation. Regulated pathogens are often present at low concentrations and it is time- and labor-intensive to monitor for them. It would be useful if surrogate organisms could be identified to improve process monitoring. This research established the effectiveness of using a chromogenic substrate for more rapid enumeration of fecal coliforms and a spread-plating method for more rapid enumeration of Salmonella in biosolids. Small batch reactors and bench-scale anaerobic digesters were used to better establish pathogen inactivation in anaerobic digesters at temperatures of 51-55°C, and comparisons were made between the inactivation of pathogens and proposed surrogate organisms. The initial batch experiments indicated that both helminths and enteric viruses were inactivated by 3-log10 within 30 minutes to 2 hours at these temperatures. However, inactivation was less rapid in the bench-scale anaerobic digester experiments, perhaps because of non-uniform mixing or heating. Helminth inactivation was the most delayed, requiring 4 hours at 55°C or an estimated 24 hours at 51°C for 2-log10 inactivation. Fecal coliforms and male-specific coliphages were the most promising surrogate organisms for enteric viruses. No appropriate surrogate organism for helminths was identified. Fungi were inactivated too rapidly to be an appropriate helminth surrogate organism. Sporulating bacteria and somatic coliphages were not significantly inactivated in this project. Enterococci were inactivated, but in the bench-scale digesters some fraction of the population was more heat resistant and persisted for the duration of the experiments. There were attempts to adjust the ammonia concentrations in the experiments through the addition of ammonium hydroxide or urea, but these were unsuccessful. Matrix effect differences between facilities were identified. The degree of treatment necessary to inactivate pathogens may vary between facilities; fecal coliforms and male-specific coliphages may be useful in developing data sets of organism inactivation for thermophilic anaerobic digestion.
Publications
- Type:
Journal Articles
Status:
Submitted
Year Published:
2016
Citation:
Carroll, Z.S., and S.C. Long. 2016. Bench-scale Analysis of Surrogates for Anaerobic Digestion Processes. Water Environment Research 88(5): 458-467.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2015
Citation:
Carroll, Z.S. and S.C. Long. 2015. Pathogens and Surrogate Organisms in Anaerobic Digestion -- Temperature, Time, and Ammonia Effects. Proceedings of the 88th Annual Water Environment Federation Technical Exhibit and Conference (WEFTEC) 2015, September 26-30 (2015), Chicago, IL.
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2016
Citation:
Carroll, Z.S., and S.C. Long. 2016. Inactivation of Pathogens and Surrogate Organisms in Anaerobic Digestion Systems. Presented at WATERCON 2016, March 21-24 (2016), Springfield, IL.
- Type:
Journal Articles
Status:
Other
Year Published:
2017
Citation:
Carroll, Z.S., and S.C. Long. In preparation for submission to Water Environment Research. Pathogen and Surrogate Organism Inactivation in Small Batch Anaerobic Digesters.
- Type:
Journal Articles
Status:
Other
Year Published:
2017
Citation:
Carroll, Z.S., and S.C. Long. In preparation for submission to Water Environment Research. Time/Temperature Analysis of Pathogens and Surrogate Organisms in Bench-scale Anaerobic Digestion.
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Progress 10/01/14 to 09/30/15
Outputs
Target Audience:The target audiences are: 1) Wisconsin Department of Natural Resources staff involved with septage, wastewater and agriculture programs 2) WIsconsin Division of Public Health staff involved with the Surveillance and Outbreak Support team 3) Wisconsin County Health Department staff involved with water quality 4) University of WIsconsin Department of Civil and Environmental Engineering Graduate Program members Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?The doctoral student, Zachary Carroll, was assigned as a mentor to the undergraduate researcher, Josh Ferraro. Mr. Carroll provided hands on training in the laboratory and guided the experiments. Mr. Ferraro will be graduating with his BS in May 2016, has been accepted to Pharmacy School, and is currently applying to Dental Schools. How have the results been disseminated to communities of interest?Traditional academic dissemination route have been conducted. Conference presentations and a journal article have been commpleted/planned. In addition, the doctoral student on this project, Zachary Carroll, has presented his work as part of the joint Environmental Enginnering/Water Science and Technology graduate seminar course in Spring 2015. The doctoral student on this project, Zachary Carroll, has become a University of Wisconsin STEM Fellow. As part of this program, he developed an outreach program titled "Toilets to Tomatoes." This module includes descriptions of the wastewater treatment process, a hands-on exercise in flocculation and filtration, visual comparisons of plants grown with biosolid ammendments and those with chemical fertilizers, and more. Mr. Carroll has presented this program at three venues to date: UW Science Expeditions; Randall Elementary School Super Science Saturday; and UW Family Gardening Day. What do you plan to do during the next reporting period to accomplish the goals?The third and final run of the bench scale reactors will be completed in early 2016, including reactors at 36°C, 51°C, and 51°C with urea addition to the feed solids. At that point, detailed data analysis and re-evaluation of the time-temperature requirements to affect 2 log inactivation of helminth ova and 3 log inactivation of enteric viruses will be conducted. Recommendations will be shared with stakeholders. Continued presentations of the "Toilets to Tomatoes" education program are planned for 2016.
Impacts
What was accomplished under these goals?
The project moved into the second phase this year. Remaining helminth and virus samples from the phase I batch reactors were analyzed and the first two runs of the phase II bench-scale reactors were completed. This included analysis of pathogen (helminths and viruses) and potential surrogate organism (fecal coliforms, E. coli, enterococci, male-specific coliphages, somatic coliphages, and fungi) inactivation in 36°C, 51°C, and 55°C reactors using solids from the first facility. The same tests were done using solids from the second facility in 51°C, 51°C with urea addition to the feed solids to increase ammonia production, and 55°C reactors. The surrogate organism analysis is complete, and pathogen analysis is ongoing. Initial results from the bench-scale reactors indicate a longer period of time before organism inactivation begins than observed in the batch reactors. The third and final run of the bench scale reactors will be completed in early 2016, including reactors at 36°C, 51°C, and 51°C with urea addition to the feed solids. The results from the phase I batch reactors were presented at WEFTEC 2015. An interactive outreach station was developed in the spring in cooperation with the Wisconsin Idea STEM Fellows program (part of the NSF Portal to the Public). This focused on the production of biosolids, potential safety concerns, and the regulations and treatments to address those concerns. It also included a simple water treatment activity for children. Three presentations of this station were made, with future ones planned for 2016.
Publications
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2015
Citation:
Carroll, Z.S. and S.C. Long. 2015. Pathogens and Surrogate Organisms in Anaerobic Digestion -- Temperature, Time, and Ammonia Effects. Proceedings of the 88th Annual Water Environment Federation Technical Exhibit and Conference (WEFTEC) 2015, September 26-30 (2015), Chicago, IL.
- Type:
Journal Articles
Status:
Accepted
Year Published:
2016
Citation:
Carroll, Z.S., and S.C. Long. In press. Bench-scale Analysis of Surrogates for Anaerobic Digestion Processes. Accepted for publication in Water Environment Research, September 2015.
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2016
Citation:
Carroll, Z.S. and S.C. Long. Inactivation of Pathogens and Surrogate Organisms in Anaerobic Digestion Systems. To be presented at WaterCon2016, March 21-24, 2016, Springfield, IL.
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Progress 10/01/13 to 09/30/14
Outputs
Target Audience: The target audiences are: 1) Wisconsin Department of Natural Resources staff involved with septage, wastewater and agriculture programs 2) WIsconsin Division of Public Health staff involved with the Surveillance and Outbreak Support team 3) Wisconsin County Health Department staff involved with water quality 4) University of WIsconsin Department of Civil and Environmental Engineering Graduate Program members Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided? The doctoral student, Zachary Carroll, was assigned as a mentor to the undergraduate researcher, Peter Balogun. Mr. Carroll provided hands on training in the laboratory and guided the experiments. Mr. Balogun is a member of an underrepresented minority group in Science and Engineering. How have the results been disseminated to communities of interest? Long, S.C. and Z.S. Carroll. "Beneficial Reuse and Pathogen Risk" as par of a series of three training workshops for the Wisconsin Department of Natural Resources. Presented March 20, 2014 in person and as a webinar. Carroll, Z.S. "Expanding Acceptance and Use of Anaerobically Digested Biosolids by Promoting Microbial Safety" A seminar presented as part of the Environmental Engineering Graduate Seminar course, April 1. 2014. What do you plan to do during the next reporting period to accomplish the goals? Phase I Microcosm studies should be completed in late Spring 2015. The results from this portion of the project will inform the design of the bench-scale mesocosm studies. These will be conducted for two or three of the microscom study sites, depending on the results of statisical analyses (i.e. for sites that performed differently). In parallel, time studies following a single plug of material through Madison Metropolitan Sewerage District's new class, a thermophilic anaerobic digestion process will be conducted during each climatic season.
Impacts
What was accomplished under these goals?
The Phase I Microcosm Studies are nearly complete, excepting only the pathogen analysis for the final facility studied. Results up to this point indicate that Ascaris ova and enteric viruses are rapidly inactivated at 55°C, with 3-4 log10 inactivation within 30 minutes. Enteric viruses were also inactivated by 3-4 log10 within 30 minutes at 51°C. Ascaris ova were more resistant at 51°C; 50% inactivation was observed within 30 minutes. Future results will better establish Ascaris ova survival at longer timespans at this temperature. Increased ammonia concentrations did not influence Ascaris ova survival under the conditions studied, and it may have influenced virus inactivation in solids from one of the studied facilities. Ammonia did have a significant effect on fecal coliforms and E. coli in all facilities studied, increasing the degree of inactivation by about 1 log10 within 30 minutes at 51°C. This demonstrates one of the difficulties in finding a surrogate organism for Ascaris ova; they often respond differently to environmental stresses than other organisms commonly present in wastewater. Male-specific coliphages remain a promising surrogate organism for enteric viruses. In all conditions studied, male-specific coliphages were inactivated at a slower rate than enteric viruses. Unlike many of the other potential surrogate organisms, male-specific coliphages were significantly inactivated within 2 hours at 51°C, indicating similar inactivation conditions to enteric viruses, just at a slower rate. No single surrogate organism was identified for Ascaris ova. Fungi were inactivated more rapidly than Ascaris ova, especially at lower temperatures. Sporulating bacteria were not significantly inactivated even within 24 hours at conditions that inactivated Ascaris ova 3-4 log10 to below detectable limits within 30 minutes. Enteric bacteria may be the most useful measure among the tested organisms for approximating Ascaris ova inactivation, but their varying response to other matrix effects, such as ammonia, causes difficulty in establishing a standard that can be applied across many different treatment facilities. This year focused on the Phase I Microcosm Studies. These were completed for the second and third facility of study. Sample extraction and surrogate organism analysis were completed for the fourth (final) facility of study, and the pathogen analysis will be completed early next year. Following the completion of this analysis, the project will proceed into the Phase II Bench Scale Digester Studies. In summary, the biosolids from three regional wastewater treatment facilities were examined for inactivation of two regulated pathogens, enteric viruses and Ascaris ova, over a narrow thermophilic temperature range. Alongside these pathogens, surrogate organisms (organisms that are not themselves pathogens but easier and faster to measure than the pathogens) were also measured. Results demonstrate that regulatory levels of virus inactivation can be achieved even when temperatures drop to 51 degrees C and that coliphages (viruses that only infect bacteria) may be a useful surrogate as they can be measured in 1 day. As in many other studies, Ascaris ova are more difficult to inactivate and no single surrogate appears appropriate to estimate Ascaris kill.
Publications
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Progress 01/01/13 to 09/30/13
Outputs
Target Audience: The project has completed the first year of work. The graduate and undergraduate students have interacted with operations staff at two Publicly Owned Treatment Works to obtain samples. However, the experimental work is still in its begining stages, so no presentations or outreach activities have yet been completed. Ultimately, the wastewater and biosolids user communities will be targeted in addition to traditional peer-reviewed publications. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided? The doctoral student has been training and mentoring the undergraduate student working on this project. The undergraduate student has been involved in experimental design, execution and data management tasks. How have the results been disseminated to communities of interest? The project is not yet at the stage where dissemination of results is appropriate. What do you plan to do during the next reporting period to accomplish the goals? As stated above, continued microcosm testing should be completed by the end of the next reporting period (December 2014). The information will be used to inform bench-scale studies and serve as the basis for the students to submit abstracts for presentation of their work at professional meetings.
Impacts
What was accomplished under these goals?
A series of microcosm experiments using a factorial design have been performed to date. These included evaluation of two treatment temperatures (37C mesophilic and 53C thermophilic), evaluation of biosolids from two treatment facilities (one small and one large determined by daily plant flow in gallons per day), and pH associated ammonia/ammonium ratios. Analysis of enteric viruses and its surrogates has been completed on biosolids from both treatment facilities. Analysis of helminths and its surrogates has been completed on biosolids from one treatment facility and is on-going with biosolids from the other facility. Testing with biosolids from one to two additional treatment facilities is planned.
Publications
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Progress 01/01/12 to 12/31/12
Outputs
OUTPUTS: In the intervening three months, a doctoral student and an hourly student have been recruited to work on the project. These students have received proper safety training and are now certified to work with wastewater and biosolids. The doctoral student has also been able to evaluate options for methods of (1) quantifying free ammonia and ammonium in samples, (2) quantifying Closttridium sp. and Clostridium perfringens spores in samples, and (3) enumerating fungal spores and populations in samples. The doctoral student is currently working on completing "Standard Operating Procedure" documents for selected methods to be applied in the experimental phase of work. PARTICIPANTS: Sharon C. Long, Principal Investigator, Professor of Soil Science, University of Wisconsin Madison; Zachary S. Carroll, Graduate Research Assistant, Doctoral Student of Environmental Engineering, University of Wisconsin Madison; Peter Balogun, Student Hourly Research Assistant, Undergraduate Student, University of Wisconsin Madison. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
There are no significant impacts or outcomes to report as yet. We are pleased to report that the project has recruited talented students and experimental work will proceed when the students return for Spring Semester.
Publications
- No publications reported this period
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