1
|
Almansa X, Starostka R, Raskin L, Zeeman G, De Los Reyes F, Waechter J, Yeh D, Radu T. Anaerobic Digestion as a Core Technology in Addressing the Global Sanitation Crisis: Challenges and Opportunities. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:19078-19087. [PMID: 37956995 PMCID: PMC10702437 DOI: 10.1021/acs.est.3c05291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Revised: 10/27/2023] [Accepted: 10/30/2023] [Indexed: 11/21/2023]
Abstract
Successfully addressing the complex global sanitation problem is a massive undertaking. Anaerobic digestion (AD), coupled with post-treatment, has been identified as a promising technology to contribute to meeting this goal. It offers multiple benefits to the end users, such as the potential inactivation of pathogenic microorganisms in waste and the recovery of resources, including renewable energy and nutrients. This feature article provides an overview of the most frequently applied AD systems for decentralized communities and low- and lower-middle-income countries with an emphasis on sanitation, including technologies for which pathogen inactivation was considered during the design. Challenges to AD use are then identified, such as experience, economics, knowledge/training of personnel and users, and stakeholder analysis. Finally, accelerators for AD implementation are noted, such as the inclusion of field studies in academic journals, analysis of emerging contaminants, the use of sanitation toolboxes and life cycle assessment in design, incorporation of artificial intelligence in monitoring, and expansion of undergraduate and graduate curricula focused on Water, Sanitation, and Hygiene (WASH).
Collapse
Affiliation(s)
| | - Renata Starostka
- Department
of Civil and Environmental Engineering, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Lutgarde Raskin
- Department
of Civil and Environmental Engineering, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Grietje Zeeman
- Wageningen
University & Research, Wageningen, 6708PB, The Netherlands
| | - Francis De Los Reyes
- Department
of Civil, Construction, and Environmental Engineering, North Carolina State University, Raleigh, North Carolina 27695-7908, United
States
| | | | - Daniel Yeh
- Department
of Civil and Environmental Engineering, University of South Florida, Florida 33620, United States
| | - Tanja Radu
- School
of Architecture, Building and Civil Engineering, Loughborough University, Loughborough LE11 3TU, United
Kingdom
| |
Collapse
|
2
|
Kamdem CN, Tiofack AAZ, Mewamba EM, Tchounkeu EY, Tatang JRA, Mengoue ELT, Mbagnia CMT, Fogue PS, Womeni HM, Simo G. Fine mapping of Ascaris lumbricoides, Trichuris trichiura and hookworm infections in sub-districts of Makenene in Centre Region of Cameroun. Sci Rep 2022; 12:13935. [PMID: 35978014 PMCID: PMC9385646 DOI: 10.1038/s41598-022-18285-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Accepted: 08/09/2022] [Indexed: 11/20/2022] Open
Abstract
Preventive chemotherapy (PC) that remains the main control strategy recommended by the World Health Organization to achieve the elimination of soil-transmitted helminth (STH) infections as a public health problem must be strengthened by identifying the remaining transmission hot-spots for the deployment of appropriate control measures. This study was designed to assess the prevalence and infections intensities of soil-transmitted helminths and perform micro scale mapping in order to identify transmission hot-spots for targeted control operations. Stool samples were collected from 1775 children in ten primary schools of eight sub-districts of Makenene in Cameroon. Kato Katz technique was used to process and examine stool samples to detect the eggs of soil-transmitted nematodes. The prevalence of soil-transmitted helminth species as well as the infection intensities was compared. Data visualizations in forms of maps were made using Quantum geographic information system (QGIS) software. The overall prevalence of soil-transmitted helminth infections was 4.8% with a 95% confidence interval (CI) of 3.8–5.9%: 3.0% (95% CI 2.2–3.9) for Ascaris lumbricoides, 1.4% (95% CI 0.9–2.0) for Trichuris trichiura and 0.8% (95% CI 0.5–1.4) for hookworms. The prevalence of soil-transmitted helminth species differ significantly between schools and sub-districts. The intensity of infections was light (2.4%, 1.1% and 0.8%), moderate (0.4%, 0.1% and 0.1%) and heavy (0.2%, 0.2% and 0%) for A. lumbricoides, T. trichiura and hookworm respectively. The mean intensity of infections was 7255 EPG for A. lumbricoides, 2900 EPG for T. trichiura and 298 EPG for hookworm. Between schools, significant difference was recorded in the means of infection intensities of T. Trichiura and hookworms but not for A. lumbricoides. This difference was also significant for T. Trichiura when comparison were between sex. No significant difference were recorded when the comparison were between age. Fine mapping revealed that children harbouring heavy infections were clustered in the same sub-districts; highlighting the presence of high endemicity sub-districts and hot-spots for the transmission of different soil-transmitted helminth species. This study showed a diversity in the prevalence and transmission of different soil-transmitted helminth species. It also hightlighted the need for micro scale mapping to enable the localisation of high endemicity sub-districts and transmission hot-spot sites where targeted control operations must be deployed to achieve STH elimination.
Collapse
Affiliation(s)
- Cyrille Nguemnang Kamdem
- Molecular Parasitology and Entomology Unit, Department of Biochemistry, Faculty of Science, University of Dschang, PO Box 67, Dschang, Cameroon
| | - Auvaker Arnol Zebaze Tiofack
- Molecular Parasitology and Entomology Unit, Department of Biochemistry, Faculty of Science, University of Dschang, PO Box 67, Dschang, Cameroon
| | - Estelle Mezajou Mewamba
- Molecular Parasitology and Entomology Unit, Department of Biochemistry, Faculty of Science, University of Dschang, PO Box 67, Dschang, Cameroon
| | - Esthelline Yangea Tchounkeu
- Molecular Parasitology and Entomology Unit, Department of Biochemistry, Faculty of Science, University of Dschang, PO Box 67, Dschang, Cameroon
| | - Joël Rostand Atiokeng Tatang
- Research Unit of Biology and Applied Ecology, Department of Animal Biology, Faculty of Science, University of Dschang, Dschang, Cameroon
| | - Edmond Loic Tekeu Mengoue
- Molecular Parasitology and Entomology Unit, Department of Biochemistry, Faculty of Science, University of Dschang, PO Box 67, Dschang, Cameroon
| | - Carole Mureille Tchami Mbagnia
- Parasitology and Ecology Laboratory, Department of Animal Biology and Physiology, Faculty of Science, University of Yaoundé I, Yaoundé, Cameroon
| | - Pythagore Soubgwi Fogue
- Molecular Parasitology and Entomology Unit, Department of Biochemistry, Faculty of Science, University of Dschang, PO Box 67, Dschang, Cameroon
| | - Hilaire Macaire Womeni
- "Unité de Recherche de Biochimie, des plantes Médicinales, des Sciences Alimentaires et Nutrition", University of Dschang, Dschang, Cameroon
| | - Gustave Simo
- Molecular Parasitology and Entomology Unit, Department of Biochemistry, Faculty of Science, University of Dschang, PO Box 67, Dschang, Cameroon.
| |
Collapse
|
3
|
Wells EC, Vidmar AM, Webb WA, Ferguson AC, Verbyla ME, de Los Reyes FL, Zhang Q, Mihelcic JR. Meeting the Water and Sanitation Challenges of Underbounded Communities in the U.S. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:11180-11188. [PMID: 35930490 DOI: 10.1021/acs.est.2c03076] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Water and sanitation (wastewater) infrastructure in the United States is aging and deteriorating, with massive underinvestment over the past several decades. For many years, lack of attention to water and sanitation infrastructure has combined with racial segregation and discrimination to produce uneven access to water and wastewater services resulting in growing threats to human and environmental health. In many metropolitan areas in the U.S., those that often suffer disproportionately are residents of low-income, minority communities located in urban disadvantaged unincorporated areas on the margins of major cities. Through the process of underbounding (the selective expansion of city boundaries to exclude certain neighborhoods often based on racial demographics or economics), residents of these communities are disallowed municipal citizenship and live without piped water, sewage lines, and adequate drainage or flood control. This Perspective identifies the range of water and sanitation challenges faced by residents in these communities. We argue that future investment in water and sanitation should prioritize these communities and that interventions need to be culturally context sensitive. As such, approaches to address these problems must not only be technical but also social and give attention to the unique geographic and political setting of local infrastructures.
Collapse
Affiliation(s)
- E Christian Wells
- Department of Anthropology, University of South Florida, Tampa, Florida 33620, United States
| | - Abby M Vidmar
- Department of Anthropology, University of South Florida, Tampa, Florida 33620, United States
| | - W Alex Webb
- Department of Anthropology, University of South Florida, Tampa, Florida 33620, United States
| | - Alesia C Ferguson
- Department of Built Environment, North Carolina Agriculture and Technical State University, Greensboro, North Carolina 27411, United States
| | - Matthew E Verbyla
- Department of Civil, Construction, and Environmental Engineering, San Diego State University, San Diego, California 92182, United States
| | - Francis L de Los Reyes
- Department of Civil, Construction, and Environmental Engineering, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Qiong Zhang
- Department of Civil & Environmental Engineering, University of South Florida, Tampa, Florida 33620, United States
| | - James R Mihelcic
- Department of Civil & Environmental Engineering, University of South Florida, Tampa, Florida 33620, United States
| |
Collapse
|
4
|
Conventional and Innovative Hygienization of Feedstock for Biogas Production: Resistance of Indicator Bacteria to Thermal Pasteurization, Pulsed Electric Field Treatment, and Anaerobic Digestion. ENERGIES 2021. [DOI: 10.3390/en14071938] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Animal by-products (ABP) can be valorized via anaerobic digestion (AD) for biogas energy generation. The digestate issued from AD process is usually used to fertilize farming land for agricultural activities, which may cause potential sanitary risk to the environment. The European Union (EU) requires that certain ABP be thermally pasteurized in order to minimize this sanitary risk. This process is called hygienization, which can be replaced by alternative nonthermal technologies like pulsed electric field (PEF). In the present study, Enterococcus faecalis ATCC 19433 and Escherichia coli ATCC 25922 were used as indicator bacteria. Their resistance to thermal pasteurization and PEF treatment were characterized. Results show that Ent. faecalis and E. coli are reduced by 5 log10 in less than 1 min during thermal pasteurization at 70 °C. The critical electric field strength was estimated at 18 kV∙cm−1 for Ent. faecalis and 1 kV∙cm−1 for E. coli. “G+” bacteria Ent. faecalis are generally more resistant than “G−” bacteria E. coli. AD process also plays an important role in pathogens inactivation, whose performance depends on the microorganisms considered, digestion temperature, residence time, and type of feedstock. Thermophilic digestion is usually more efficient in pathogens removal than mesophilic digestion.
Collapse
|
5
|
Espinosa MF, Sancho AN, Mendoza LM, Mota CR, Verbyla ME. Systematic review and meta-analysis of time-temperature pathogen inactivation. Int J Hyg Environ Health 2020; 230:113595. [DOI: 10.1016/j.ijheh.2020.113595] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 06/04/2020] [Accepted: 07/06/2020] [Indexed: 11/16/2022]
|
6
|
Detection of Helminth Ova in Wastewater Using Recombinase Polymerase Amplification Coupled to Lateral Flow Strips. WATER 2020. [DOI: 10.3390/w12030691] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Ascaris lumbricoides is a major soil-transmitted helminth that is highly infective to humans. The ova of A. lumbricoides are able to survive wastewater treatment, thus making it an indicator organism for effective water treatment and sanitation. Hence, Ascaris ova must be removed from wastewater matrices for the safe use of recycled water. Current microscopic techniques for identification and enumeration of Ascaris ova are laborious and cumbersome. Polymerase chain reaction (PCR)-based techniques are sensitive and specific, however, major constraints lie in having to transport samples to a centralised laboratory, the requirement for sophisticated instrumentation and skilled personnel. To address this issue, a rapid, highly specific, sensitive, and affordable method for the detection of helminth ova was developed utilising recombinase polymerase amplification (RPA) coupled with lateral flow (LF) strips. In this study, Ascaris suum ova were used to demonstrate the potential use of the RPA-LF assay. The method was faster (< 30 min) with optimal temperature at 37 °C and greater sensitivity than PCR-based approaches with detection as low as 2 femtograms of DNA. Furthermore, ova from two different helminth genera were able to be detected as a multiplex assay using a single lateral flow strip, which could significantly reduce the time and the cost of helminth identification. The RPA-LF system represents an accurate, rapid, and cost-effective technology that could replace the existing detection methods, which are technically challenged and not ideal for on-site detection in wastewater treatment plants.
Collapse
|
7
|
Harroff LA, Liotta JL, Bowman DD, Angenent LT. Current time-temperature relationships for thermal inactivation of Ascaris eggs at mesophilic temperatures are too conservative and may hamper development of simple, but effective sanitation. WATER RESEARCH X 2019; 5:100036. [PMID: 31535088 PMCID: PMC6743028 DOI: 10.1016/j.wroa.2019.100036] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Revised: 08/19/2019] [Accepted: 08/30/2019] [Indexed: 06/10/2023]
Abstract
Ascaris eggs are commonly used as indicators for pathogen inactivation during the treatment of fecal sludge and wastewater due to their highly resistant lipid membrane and ability to survive in the environment for long periods of time. Current guidelines suggest that thermal treatment alone cannot inactivate Ascaris eggs at temperatures below 45 °C, although some evidence in the literature suggests this to be incorrect. Here, we performed a controlled experiment to test the effect of mesophilic temperatures on Ascaris inactivation. We exposed Ascaris suum eggs to a temperature gradient between 34°C and 45 °C under anaerobic and aerobic conditions to observe the required exposure times for a 3-log reduction. Indeed, we found that temperatures lower than 45 °C did inactivate these eggs, and the required exposure times were up to two orders of magnitude shorter than suggested by current guidelines. Results from the anaerobic exposures were used to develop a time-temperature relationship that is appropriate for Ascaris inactivation at mesophilic temperatures. Data from the literature demonstrated that our relationship is conservative, with faster inactivation occurring under environmental conditions when Ascaris eggs were suspended in fecal sludge or manure. A specific aerobic relationship was not developed, but we demonstrated that aerobic conditions cause faster inactivation than anaerobic conditions. Therefore, the anaerobic relationship provides a conservative guideline for both conditions. We demonstrate that relatively low temperatures can considerably impact Ascaris viability and suggest that mesophilic temperatures can be used in waste treatment processes to inactivate pathogens. The development of safe, low-input, mesophilic treatment processes is particularly valuable for ensuring universal access to safe sanitation and excreta management.
Collapse
Affiliation(s)
- Lauren A. Harroff
- Department of Biological and Environmental Engineering, Cornell University, Ithaca, NY, 14853, USA
| | - Janice L. Liotta
- Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853, USA
| | - Dwight D. Bowman
- Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853, USA
| | - Largus T. Angenent
- Center for Applied Geosciences, University of Tübingen, 72074, Tübingen, Germany
| |
Collapse
|
8
|
Zhao Q, Liu Y. Is anaerobic digestion a reliable barrier for deactivation of pathogens in biosludge? THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 668:893-902. [PMID: 30870755 PMCID: PMC7112049 DOI: 10.1016/j.scitotenv.2019.03.063] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Revised: 03/04/2019] [Accepted: 03/05/2019] [Indexed: 04/14/2023]
Abstract
As World Health Organization advocates, the global burden of sanitation related disease and access to safely managed sanitation and safely treated wastewater should be monitored strictly. However, the spread of pathogens through various agricultural applications or direct discharge of sewage sludge generated in municipal wastewater treatment plants poses a serious challenge on the environment and public health. Anaerobic digestion (AD), the principal method of stabilizing biosolids, can efficiently and largely deactivate viable pathogens, including parasite, virus, and the pathogens harboring antibiotic resistance genes. This review aims to provide a critical overview regarding the deactivation of sludge-associated pathogens by AD, through which a serious concern on the effectiveness and rationality of AD towards sludge pathogens control was raised. Meanwhile, the underlying deactivation mechanisms and affecting factors were all discussed, with the focus on pathogen-associated modeling, engineering design and technological aspects of AD. Lastly, a matric method incorporating the operating strategy of AD with the risk assessment was proposed for evaluating the reliability of AD-based pathogen deactivation, while the research agenda forward was also outlined.
Collapse
Affiliation(s)
- Qian Zhao
- School of Municipal and Environmental Engineering, Shandong Jianzhu University, 1000 Fengming Road, Jinan 250101, China; Shandong Province Co-Innovation Center of Green Building, Jinan 250101, China; Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Jinan 250100, China.
| | - Yu Liu
- School of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798, Singapore; Advanced Environmental Biotechnology Centre, Nanyang Environment and Water Research Institute, Nanyang Technological University, 1 Cleantech Loop, CleanTech One, 637141, Singapore.
| |
Collapse
|
9
|
Naidoo D, Foutch GL. The time-temperature relationship for the inactivation of Ascaris eggs. JOURNAL OF WATER, SANITATION, AND HYGIENE FOR DEVELOPMENT : A JOURNAL OF THE INTERNATIONAL WATER ASSOCIATION 2017; 8:123-126. [PMID: 33384866 PMCID: PMC7734376 DOI: 10.2166/washdev.2017.102] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Accepted: 11/01/2017] [Indexed: 06/11/2023]
Abstract
A time-temperature plot presenting the inactivation of Ascaris eggs is expanded with additional literature data. The information is of value to designers and operators of sanitation equipment who have Ascaris inactivation as an objective.
Collapse
Affiliation(s)
- D Naidoo
- School of Life Sciences, Westville Campus, University of KwaZulu-Natal, Durban 4051, South Africa
- School of Computing and Engineering, University of Missouri-Kansas City, Kansas City, MO 64110, USA and Chemical Engineering, Howard Campus, University of KwaZulu-Natal, Durban 4001, South Africa E-mail:
| | - G L Foutch
- School of Life Sciences, Westville Campus, University of KwaZulu-Natal, Durban 4051, South Africa
- School of Computing and Engineering, University of Missouri-Kansas City, Kansas City, MO 64110, USA and Chemical Engineering, Howard Campus, University of KwaZulu-Natal, Durban 4001, South Africa E-mail:
| |
Collapse
|
10
|
Harroff LA, Liotta JL, Bowman DD, Angenent LT. Inactivation of Ascaris Eggs in Human Fecal Material Through In Situ Production of Carboxylic Acids. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:9729-9738. [PMID: 28759229 DOI: 10.1021/acs.est.7b02014] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Discovering new ways to inactivate pathogens in human waste is critical for the improvement of worldwide access to sanitation and for the reduction of the environmental impact of conventional waste treatment processes. Here, we utilized the carboxylate platform and chain elongation to produce n-butyric acid and n-caproic acid via the anaerobic fermentation of human fecal material. Then, we inactivated Ascaris eggs through exposure to these carboxylic acids. Using batch experiments with human fecal material as substrate, we accumulated n-butyric acid and n-caproic acid at total concentrations (uncharged acid plus conjugate base) of 257 and 27.1 mM, respectively. We then showed that carboxylic acids at these concentrations inactivated Ascaris eggs when the pH was below the pKa for the acids, causing them to exist primarily in the uncharged forms. We observed that uncharged carboxylic acids affected viability rather than the pH itself or conjugate bases. In addition, we modeled the viability of Ascaris eggs as a function of uncharged carboxylic acid concentration for n-butyric acid and n-caproic acid at exposure times of 2, 6, 12, and 20 days. The results presented here indicate that in situ biological production of carboxylic acids in HFM provides a promising method of pathogen inactivation and may lead to new developments in sanitation technology and treatment of fecal sludge.
Collapse
Affiliation(s)
| | | | | | - Largus T Angenent
- Atkinson Center for a Sustainable Future , Ithaca, New York 14853, United States
- Center for Applied Geosciences, University of Tübingen , 72074 Tübingen, Germany
| |
Collapse
|
11
|
Rojas-Oropeza M, Hernández-Uresti AS, Ortega-Charleston LS, Cabirol N. Effect of volatile fatty acids in anaerobic conditions on viability of helminth ova (Ascaris suum) in sanitization of municipal sludge. ENVIRONMENTAL TECHNOLOGY 2017; 38:2202-2208. [PMID: 27784197 DOI: 10.1080/09593330.2016.1254281] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2016] [Accepted: 10/23/2016] [Indexed: 06/06/2023]
Abstract
The present work aimed at evaluating the effect of four different mixtures of diverse volatile fatty acids (VFAs) on the viability of helminth ova (Ascaris suum), under mesophilic (35°C) anaerobic conditions and at different incubation times, in order to reproduce the process of two-phase anaerobic digestion. The mixtures of VFAs contained acetic, propionic, butyric, valeric, and isovaleric acids, used at concentrations normally found in acidogenic anaerobic digesters. The four treatments all showed a reduction in Ascaris suum ova viability, among which Treatment III (4.2 g-acetic acid L-1 + 2.2 g-propionic acid L-1 + 0.6 g-valeric acid L-1 + 0.6 g-isovaleric acid L-1) resulted the most efficient. We found that the full effect of VFAs on the viability loss of Ascaris suum ova in mesophilic conditions requires a minimum incubation time of 3 days. The highest efficiency in the loss of viability was observed with Treatment III and 4-day incubation. Interestingly, the proportion of acetic acid was three times as much in this treatment than in the other ones and resulted in an effect in a minimum time of 3 days. The mesophilic condition, however, was not sufficient to induce a complete loss of viability.
Collapse
Affiliation(s)
- Marcelo Rojas-Oropeza
- a Departamento de Ecología y Recursos Naturales, Facultad de Ciencias , Universidad Nacional Autónoma de México, Ciudad Universitaria , México City , México
| | | | | | - Nathalie Cabirol
- a Departamento de Ecología y Recursos Naturales, Facultad de Ciencias , Universidad Nacional Autónoma de México, Ciudad Universitaria , México City , México
| |
Collapse
|
12
|
Forbis-Stokes AA, O'Meara PF, Mugo W, Simiyu GM, Deshusses MA. On-Site Fecal Sludge Treatment with the Anaerobic Digestion Pasteurization Latrine. ENVIRONMENTAL ENGINEERING SCIENCE 2016; 33:898-906. [PMID: 27924135 PMCID: PMC5134843 DOI: 10.1089/ees.2016.0148] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Accepted: 06/30/2016] [Indexed: 05/15/2023]
Abstract
The Anaerobic Digestion Pasteurization Latrine (ADPL) is a self-contained and energy neutral on-site sanitation system using anaerobic digestion of fecal sludge to generate biogas and then uses the biogas to pasteurize the digester effluent at 65-75°C to produce a safe effluent that can be reused locally as a fertilizer. Two ADPL systems were installed on residential plots with 17 and 35 residents in a peri-urban area outside of Eldoret, Kenya. Each system comprised three toilets built above a floating dome digester and one heat pasteurization system to sanitize the digested effluent. ADPLs are simple systems, with no moving parts and relying on gravity-induced flows. Adoption at the two sites was successful, and residents reported that the systems had little to no odor or flies. ADPLs were monitored for biogas production and temperatures in the pasteurization system. ADPLs serving 17 and 35 residents produced on average 16 and 11 Lbiogas/person/day (maximum of 20 and 15 Lbiogas/p/d), respectively. The temperature in the sterilization system was greater than 65°C on 58% and 87% of sampling days during the most stable period of operation. Treated effluent was analyzed periodically for chemical oxygen demand (COD), biochemical oxygen demand (BOD), total ammonia nitrogen (TAN), pH, and fecal coliform (FC). On average, the effluent at the two locations contained 4,540 and 6,450 mg COD/L (an 85% or 89% reduction of the estimated input), 2,050 and 3,970 mg BOD/L, and 2,420 and 4,760 mg NH3-N, respectively, and greater than 5 log reductions of FC (nondetectable) in the sterilization tank. Results from this field study show that anaerobic digestion of minimally diluted fecal sludge can provide enough energy to pasteurize digester effluent and that the ADPL may be a suitable option for on-site fecal sludge treatment.
Collapse
Affiliation(s)
- Aaron A. Forbis-Stokes
- Department of Civil and Environmental Engineering, and Duke Global Health Institute, Duke University, Durham, North Carolina
| | | | - Wangare Mugo
- Department of Environmental Biology and Health, University of Eldoret, Eldoret, Kenya
| | - Gelas M. Simiyu
- Department of Environmental Biology and Health, University of Eldoret, Eldoret, Kenya
| | - Marc A. Deshusses
- Department of Civil and Environmental Engineering, and Duke Global Health Institute, Duke University, Durham, North Carolina
| |
Collapse
|
13
|
Kinyua MN, Wald I, Camacho-Céspedes F, Izurieta R, Haas CN, Ergas SJ. Does the use of tubular digesters to treat livestock waste lower the risk of infection from Cryptosporidium parvum and Giardia lamblia? JOURNAL OF WATER AND HEALTH 2016; 14:738-753. [PMID: 27740541 DOI: 10.2166/wh.2016.032] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Worldwide, high incidences of cryptosporidiosis and giardiasis are attributed to livestock waste. Quantitative microbial risk assessment can be used to estimate the risk of livestock related infections from Cryptosporidium parvum and Giardia lamblia. The objective of this paper was to assess the occupational and public health risks associated with management of raw and anaerobically digested livestock waste in two rural communities in Costa Rica based on fomite, soil and crop contamination and livestock waste management exposure pathways. Risks related to cattle waste were greater than swine waste due to cattle shedding more (oo)cysts. Cryptosporidium parvum also posed a greater risk than Giardia lamblia in all exposure pathways due to livestock shedding high loads of Cryptosporidium parvum oocysts and oocysts' lower inactivation rates during anaerobic digestion compared with Giardia lamblia cysts. The risk of infection from exposure to contaminated soil and crops was significantly lower for a community using tubular anaerobic digesters to treat livestock waste compared to a community where the untreated waste was applied to soil. The results indicate that treatment of livestock waste in small-scale tubular anaerobic digesters has the potential to significantly decrease the risk of infection below the World Health Organization's acceptable individual annual risk of infection (10-4).
Collapse
Affiliation(s)
- Maureen N Kinyua
- Department of Civil and Environmental Engineering, University of South Florida, 4202 E Fowler Ave ENB 118, Tampa, FL 33620, USA E-mail: ; Present address: Department of Earth and Environmental Engineering, Columbia University, 500 W. 120th St. 918 S. W. Mudd Hall, 500, Manhattan, NY 10027, USA
| | - Ileana Wald
- Department of Civil and Environmental Engineering, University of California, 760 Davis Hall Berkeley, Berkeley, CA 94720, USA
| | - Fabricio Camacho-Céspedes
- University of Georgia, Costa Rica, Apartado 108-5655 Santa Elena de Monteverde, Puntarenas, Costa Rica
| | - Ricardo Izurieta
- Department of Global Health, University of South Florida, 4202 E Fowler Ave CPH 1127, Tampa, FL 33620, USA
| | - Charles N Haas
- Department of Civil, Architectural and Environmental Engineering, Drexel University, 251 Curtis Hall, 3141 Chestnut Street, Philadelphia, PA 19104, USA
| | - Sarina J Ergas
- Department of Civil and Environmental Engineering, University of South Florida, 4202 E Fowler Ave ENB 118, Tampa, FL 33620, USA E-mail:
| |
Collapse
|
14
|
P M, C N, J BT, R K, A K, P N, F K. Key factors affecting performance of biogas latrines in urban informal areas: Case of Kampala and Nairobi, East Africa. ACTA ACUST UNITED AC 2016. [DOI: 10.5897/ajest2016.2108] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
|
15
|
Kinyua MN, Trimmer J, Izurieta R, Cunningham J, Ergas SJ. Viability and fate of Cryptosporidium parvum and Giardia lamblia in tubular anaerobic digesters. THE SCIENCE OF THE TOTAL ENVIRONMENT 2016; 554-555:167-177. [PMID: 26950630 DOI: 10.1016/j.scitotenv.2016.02.170] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2015] [Revised: 02/24/2016] [Accepted: 02/24/2016] [Indexed: 06/05/2023]
Abstract
In many developing countries where pathogenic diseases of animal waste origin, such as giardiasis and cryptosporidiosis, are often prevalent, facilities are limited to treat livestock waste. However, household-scale anaerobic digesters are currently being promoted for bioenergy production from livestock manure. Since the effluent is often used as a fertilizer for food crops, it is critical to understand the effect of environmental conditions within household-scale digesters on the viability of Cryptosporidium parvum oocysts and Giardia lamblia cysts. In this study, key environmental parameters affecting (oo)cyst inactivation were measured in four tubular anaerobic digesters, which are a type of household-scale digester promoted for treatment of swine waste in rural Costa Rica. Interviews and participant observations were used to understand digester operation and maintenance procedures. Ambient temperatures (21-24°C), near-neutral pH, total ammonia nitrogen (TAN) concentrations<250 mg/L and hydraulic retention times (HRTs) between 23 and 180 days were observed. Laboratory (oo)cysts inactivation studies were performed in bench-scale digesters, which were maintained under conditions similar to those observed in the field. Apparent first-order inactivation rate coefficients for Giardia lamblia and Cryptosporidium parvum were 0.155 ± 0.041 and 0.054 ± 0.006 day(-1), respectively. Temperature and volatile fatty acids were the main factors contributing to Cryptosporidium parvum and Giardia lamblia inactivation. A mathematical model was developed that predicts the concentration of (oo)cysts in the liquid effluent of tubular digesters like those observed in Costa Rica. A mathematical model was developed that predicts the concentration of (oo)cysts in the liquid effluent of tubular digesters like those observed in Costa Rica. Two dimensionless groups can be used to predict the performance of the digesters for inactivating pathogens; both dimensionless groups depend upon the average HRT in the digester. This is the first study to combine mathematical modeling with qualitative analysis, field and laboratory studies to predict the concentrations of (oo)cysts in tubular digester effluents.
Collapse
Affiliation(s)
- Maureen N Kinyua
- Department of Civil and Environmental Engineering, University of South Florida, 4202 E Fowler Ave ENB 118, Tampa, FL 33620, United States.
| | - John Trimmer
- Department of Civil and Environmental Engineering, University of South Florida, 4202 E Fowler Ave ENB 118, Tampa, FL 33620, United States.
| | - Ricardo Izurieta
- Department of Global Health, University of South Florida, 4202 E Fowler Ave CPH 1127, Tampa, FL 33620, United States.
| | - Jeffrey Cunningham
- Department of Civil and Environmental Engineering, University of South Florida, 4202 E Fowler Ave ENB 118, Tampa, FL 33620, United States.
| | - Sarina J Ergas
- Department of Civil and Environmental Engineering, University of South Florida, 4202 E Fowler Ave ENB 118, Tampa, FL 33620, United States.
| |
Collapse
|
16
|
Manser ND, Mihelcic JR, Ergas SJ. Semi-continuous mesophilic anaerobic digester performance under variations in solids retention time and feeding frequency. BIORESOURCE TECHNOLOGY 2015; 190:359-366. [PMID: 25965953 DOI: 10.1016/j.biortech.2015.04.111] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2015] [Revised: 04/28/2015] [Accepted: 04/29/2015] [Indexed: 06/04/2023]
Abstract
The goal of this research was to understand the effect of solids retention time (SRT) and feeding frequency on the performance of anaerobic digesters used to recover bioenergy from swine waste. Semi-continuous mesophilic anaerobic digesters were operated at varying SRTs and feeding frequencies. Performance metrics included biogas and methane production rates, biomass robustness and functionality and removals of volatile solids, soluble chemical oxygen demand, the fecal-indicator bacteria Escherichia coli, and the human pathogen Salmonella. Biochemical methane formation potential and specific methanogenic activity assays were used to demonstrate biomass robustness and functionality. Results indicated that anaerobic digesters fed weekly had higher average methane yields (0.20 vs. 0.18m(3)CH4/kg-VSadded), specific methanogenic activities (40 vs. 35ml/day), and fecal indicator bacteria destruction (99.9% vs. 99.4%) than those fed every-other day. Salmonella, soluble COD, and VS destruction did not change with varied feeding frequency; however, higher removals were observed with longer SRT.
Collapse
Affiliation(s)
- Nathan D Manser
- Department of Civil and Environmental Engineering, University of South Florida, 4202 E Fowler Avenue, ENB 118, Tampa, FL 33620, United States
| | - James R Mihelcic
- Department of Civil and Environmental Engineering, University of South Florida, 4202 E Fowler Avenue, ENB 118, Tampa, FL 33620, United States
| | - Sarina J Ergas
- Department of Civil and Environmental Engineering, University of South Florida, 4202 E Fowler Avenue, ENB 118, Tampa, FL 33620, United States.
| |
Collapse
|