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Fane S, Nocker A, Vale P, Casado MR, Cartmell E, Harris J, Fernández YB, Tyrrel S. Characterisation and control of the biosolids storage environment: Implications for E. coli dynamics. Sci Total Environ 2021; 752:141705. [PMID: 32892039 DOI: 10.1016/j.scitotenv.2020.141705] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 08/10/2020] [Accepted: 08/13/2020] [Indexed: 06/11/2023]
Abstract
E. coli survival in biosolids storage may present a risk of non-compliance with guidelines designed to ensure a quality product safe for agricultural use. The storage environment may affect E. coli survival but presently, storage characteristics are not well profiled. Typically biosolids storage environments are not actively controlled or monitored to support increased product quality or improved microbial compliance. This two-phased study aimed to identify the environmental factors that control bacterial concentrations through a long term, controlled monitoring study (phase 1) and a field-scale demonstration trial modifying precursors to bacterial growth (phase 2). Digested and dewatered biosolids were stored in operational-scale stockpiles to elucidate factors controlling E. coli dynamics. E. coli concentrations, stockpile dry solids, temperature, redox and ambient weather data were monitored. Results from ANCOVA analysis showed statistically significant (p < 0.05) E. coli reductions across storage periods with greater die-off in summer months. Stockpile temperature had a statistically significant effect on E. coli survival. A 4.5 Log reduction was measured in summer (maximum temperature 31 °C). In the phase 2 modification trials, covered stockpiles were able to maintain a temperature >25 °C for a 28 day period and achieved a 3.7 Log E. coli reduction. In winter months E. coli suppression was limited with concentrations >6 Log10 CFU g-1 DS maintained. The ANCOVA analysis has identified the significant role that physical environmental factors, such as stockpile temperature, has on E. coli dynamics and the opportunities for control.
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Affiliation(s)
- S Fane
- Water Science Institute, School of Water, Energy and Environment, Cranfield University, UK
| | - A Nocker
- IWW Rheinisch-Westfälisches Institut für Wasserforschung gemeinnützige GmbH, Germany
| | | | - M Rivas Casado
- Water Science Institute, School of Water, Energy and Environment, Cranfield University, UK
| | - E Cartmell
- Scottish Water, Dunfermline, Scotland, UK
| | - J Harris
- Water Science Institute, School of Water, Energy and Environment, Cranfield University, UK
| | - Y Bajón Fernández
- Water Science Institute, School of Water, Energy and Environment, Cranfield University, UK
| | - S Tyrrel
- Water Science Institute, School of Water, Energy and Environment, Cranfield University, UK.
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Freeman D, Bajón Fernández Y, Wilson A, McKew BA, Whitby C, Clark DR, Jefferson B, Coulon F, Hassard F. Nitrogen oxidation consortia dynamics influence the performance of full-scale rotating biological contactors. Environ Int 2020; 135:105354. [PMID: 31864025 DOI: 10.1016/j.envint.2019.105354] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2019] [Revised: 11/13/2019] [Accepted: 11/20/2019] [Indexed: 06/10/2023]
Abstract
Ammonia oxidising microorganisms (AOM) play an important role in ammonia removal in wastewater treatment works (WWTW) including rotating biological contactors (RBCs). Environmental factors within RBCs are known to impact the performance of key AOM, such that only some operational RBCs have shown ability for elevated ammonia removal. In this work, long-term treatment performance of seven full-scale RBC systems along with the structure and abundance of the ammonia oxidising bacteria (AOB) and archaea (AOA) communities within microbial biofilms were examined. Long term data showed the dominance of AOB in most RBCs, although two RBCs had demonstrable shift toward an AOA dominated AOM community. Next Generation Sequencing of the 16S rRNA gene revealed diverse evolutionary ancestry of AOB from RBC biofilms while nitrite-oxidising bacteria (NOBs) were similar to reference databases. AOA were more abundant in the biofilms subject to lower organic loading and higher oxygen concentration found at the distal end of RBC systems. Modelling revealed a distinct nitrogen cycling community present within high performing RBCs, linked to efficient control of RBC process variables (retention time, organic loading and oxygen concentration). We present a novel template for enhancing the resilience of RBC systems through microbial community analysis which can guide future strategies for more effective ammonia removal. To best of the author's knowledge, this is the first comparative study reporting the use of next generation sequencing data on microbial biofilms from RBCs to inform effluent quality of small WWTW.
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Affiliation(s)
- D Freeman
- Cranfield University, College Road, Cranfield, Bedfordshire MK43 0AL, UK; Severn Trent, 2 St Johns Street, Coventry CV1 2LZ, UK
| | - Y Bajón Fernández
- Cranfield University, College Road, Cranfield, Bedfordshire MK43 0AL, UK; Severn Trent, 2 St Johns Street, Coventry CV1 2LZ, UK
| | - A Wilson
- Severn Trent, 2 St Johns Street, Coventry CV1 2LZ, UK; Atkins Global, The Axis, 10 Holliday St, Birmingham B1 1TF, UK
| | - B A McKew
- School of Biological Sciences, University of Essex, Colchester CO4 3SQ, UK
| | - C Whitby
- School of Biological Sciences, University of Essex, Colchester CO4 3SQ, UK
| | - D R Clark
- School of Biological Sciences, University of Essex, Colchester CO4 3SQ, UK
| | - B Jefferson
- Cranfield University, College Road, Cranfield, Bedfordshire MK43 0AL, UK
| | - F Coulon
- Cranfield University, College Road, Cranfield, Bedfordshire MK43 0AL, UK
| | - F Hassard
- Cranfield University, College Road, Cranfield, Bedfordshire MK43 0AL, UK.
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Khomenko O, Dotro G, Jefferson B, Coulon F, Bajón Fernández Y. Influence of sludge layer properties on the hydraulic behaviour of gravel-based vertical flow constructed wetlands for primary treatment of sewage. Sci Total Environ 2019; 691:1137-1143. [PMID: 31466195 DOI: 10.1016/j.scitotenv.2019.07.121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2019] [Revised: 07/07/2019] [Accepted: 07/08/2019] [Indexed: 06/10/2023]
Abstract
Sludge accumulation on the first stage of French design vertical flow constructed wetlands has been reported to improve treatment performance by favouring even sewage distribution on the beds' surface and increasing water retention time. However, due to its relatively low permeability, sludge layer can restrict the hydraulic capacity of the wetlands, requiring careful consideration of the feeding and resting strategy in order to avoid system ponding. This study aimed to elucidate the impact that sludge layer properties have on its permeability and investigate artificial modifications that could enhance it. A positive impact of increased organic matter content on sludge permeability was observed, with a 3-times permeability increase for a 15 percentage points higher volatile solids content. The opposite effect was observed for total solids, where an increase of 19 percentage points led to a drop of 1.6 × 10-16 m2 on permeability. The impact of different surface modifications on drying kinetics and sludge layer properties was studied as a means to accelerate sludge layer mineralisation. Artificial modifications that modify surface tension of the sludge layer have been proved to achieve greater permeability and faster mineralisation of the sludge, with potential to achieve higher hydraulic acceptance and reduced operational costs (lower sludge accumulation) if implemented in full scale vertical flow constructed wetlands.
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Affiliation(s)
- O Khomenko
- Cranfield University, School of Water, Energy and Environment, Cranfield MK430AL, UK
| | - G Dotro
- Cranfield University, School of Water, Energy and Environment, Cranfield MK430AL, UK
| | - B Jefferson
- Cranfield University, School of Water, Energy and Environment, Cranfield MK430AL, UK
| | - F Coulon
- Cranfield University, School of Water, Energy and Environment, Cranfield MK430AL, UK
| | - Y Bajón Fernández
- Cranfield University, School of Water, Energy and Environment, Cranfield MK430AL, UK.
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Spence A, Blanco Madrigal E, Patil R, Bajón Fernández Y. Evaluation of anaerobic digestibility of energy crops and agricultural by-products. ACTA ACUST UNITED AC 2019. [DOI: 10.1016/j.biteb.2018.11.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Fernández YB, Green K, Schuler K, Soares A, Vale P, Alibardi L, Cartmell E. Biological carbon dioxide utilisation in food waste anaerobic digesters. Water Res 2015; 87:467-75. [PMID: 26143589 DOI: 10.1016/j.watres.2015.06.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2015] [Revised: 05/26/2015] [Accepted: 06/05/2015] [Indexed: 05/24/2023]
Abstract
Carbon dioxide (CO2) enrichment of anaerobic digesters (AD) was previously identified as a potential on-site carbon revalorisation strategy. This study addresses the lack of studies investigating this concept in up-scaled units and the need to understand the mechanisms of exogenous CO2 utilisation. Two pilot-scale ADs treating food waste were monitored for 225 days, with the test unit being periodically injected with CO2 using a bubble column. The test AD maintained a CH4 production rate of 0.56 ± 0.13 m(3) CH4·(kg VS(fed) d)(-1) and a CH4 concentration in biogas of 68% even when dissolved CO2 levels were increased by a 3 fold over the control unit. An additional uptake of 0.55 kg of exogenous CO2 was achieved in the test AD during the trial period. A 2.5 fold increase in hydrogen (H2) concentration was observed and attributed to CO2 dissolution and to an alteration of the acidogenesis and acetogenesis pathways. A hypothesis for conversion of exogenous CO2 has been proposed, which requires validation by microbial community analysis.
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Affiliation(s)
| | - K Green
- Cranfield University, Cranfield, Bedfordshire, MK43 0AL, UK
| | - K Schuler
- Ecole Nationale Supérieure de Chimie de Rennes, 11 Allée de Beaulieu, 35708 Rennes Cedex 7, France
| | - A Soares
- Cranfield University, Cranfield, Bedfordshire, MK43 0AL, UK
| | - P Vale
- Severn Trent Water, 2 St John's Street, Coventry, CV1 2LZ, UK
| | - L Alibardi
- Department of Industrial Engineering, University of Padova, Via Marzolo 9, 35131 Padova, Italy
| | - E Cartmell
- Cranfield University, Cranfield, Bedfordshire, MK43 0AL, UK.
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Bajón Fernández Y, Soares A, Villa R, Vale P, Cartmell E. Carbon capture and biogas enhancement by carbon dioxide enrichment of anaerobic digesters treating sewage sludge or food waste. Bioresour Technol 2014; 159:1-7. [PMID: 24632434 DOI: 10.1016/j.biortech.2014.02.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2013] [Revised: 02/02/2014] [Accepted: 02/04/2014] [Indexed: 05/07/2023]
Abstract
The increasing concentration of carbon dioxide (CO2) in the atmosphere and the stringent greenhouse gases (GHG) reduction targets, require the development of CO2 sequestration technologies applicable for the waste and wastewater sector. This study addressed the reduction of CO2 emissions and enhancement of biogas production associated with CO2 enrichment of anaerobic digesters (ADs). The benefits of CO2 enrichment were examined by injecting CO2 at 0, 0.3, 0.6 and 0.9 M fractions into batch ADs treating food waste or sewage sludge. Daily specific methane (CH4) production increased 11-16% for food waste and 96-138% for sewage sludge over the first 24h. Potential CO2 reductions of 8-34% for sewage sludge and 3-11% for food waste were estimated. The capacity of ADs to utilise additional CO2 was demonstrated, which could provide a potential solution for onsite sequestration of CO2 streams while enhancing renewable energy production.
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Affiliation(s)
- Y Bajón Fernández
- Cranfield Water Science Institute, School of Applied Sciences, Cranfield University, Cranfield, Bedfordshire MK43 0AL, UK
| | - A Soares
- Cranfield Water Science Institute, School of Applied Sciences, Cranfield University, Cranfield, Bedfordshire MK43 0AL, UK
| | - R Villa
- Cranfield Water Science Institute, School of Applied Sciences, Cranfield University, Cranfield, Bedfordshire MK43 0AL, UK
| | - P Vale
- Severn Trent Water, 2 St. John's Street, Coventry CV1 2LZ, UK
| | - E Cartmell
- Cranfield Water Science Institute, School of Applied Sciences, Cranfield University, Cranfield, Bedfordshire MK43 0AL, UK.
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