Microaerobic digestion of sewage sludge on an industrial-pilot scale: The efficiency of biogas desulphurisation under different configurations and the impact of O2 on the microbial communities

Abstract Background Digested sewage sludge has been widely applied as soil amendment for enhanced crop production. However, given that digested sludge is abundant with antibiotic resistance genes (ARGs) and antibiotic resistant bacteria, the impact of digested sludge amendment on the abundances of ARGs and microbial communities in soil and soil fauna (e.g., earthworms) remains largely unknown. In this study, the patterns of ARGs and microbial communities in soil and gut of earthworms after 80-days cultivation with digested sewage sludge amendment were investigated to gain insights into this impact. Results The results show that the digested sludge amendment increased the initial abundances of ARGs (e.g., tetA, tetQ, and sulII) in soil. However, after 80-days cultivation, the absolute abundances of target ARGs decreased by 62.3–95.4%. The reduction in ARGs absolute abundances was further enhanced by 31.4–84.7% in the presence of earthworms. In contrast, the relative abundances of some ARGs (e.g., tetA, sulI, and blaTEM−1) in the gut of earthworms increased by 41–130 folds. The microbial community structure of soil was greatly altered because of the introduction of digested sewage sludge at initial, but it recovered to its original pattern after 80-days cultivation. This could be attributed to the gradual attenuation of anaerobic microorganisms under aerobic conditions in soil. In particular, the presence of earthworms further enhanced this phenomenon. The reduction of ARGs in the amended soils was likely attributed to microbial community shift based on redundancy analysis. Several bacterial families (e.g., Saprospiraceae, Chitinophagaceae, and Rhodanobacteraceae) were significantly correlated with the target ARGs. Conclusions Our results reveal that the enrichment of ARGs in soil caused by digested sludge-amendment would recover to their original levels before amendment, highlighting the contribution of earthworms to reducing the ARG abundances in amended soil via shifting the microbial community. However, we also found that the amended soil could increase ARGs abundance in the earthworm gut, which may enhance the potential risk of ARGs spread via food chain. These results may provide a new sight on the control of ARGs occurrence and dissemination in sludge-amended soil ecosystem with consideration of the impact of earthworms.

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New findings on the anaerobic co-digestion of thermally pretreated sludge and food waste: lab and pilot scale studies

Water Science & Technology ◽

10.2166/wst.2021.422 ◽

2021 ◽

Author(s):

Andrés Donoso-Bravo ◽

Javiera Toledo-Alarcón ◽

Valentina Ortega ◽

Valeria Barría ◽

Yves Lesty ◽

...

Keyword(s):

Sewage Sludge ◽

Food Waste ◽

Negative Impact ◽

Biogas Production ◽

Pilot Scale ◽

Special Focus ◽

Innovative Strategy ◽

Treated Sewage ◽

New Findings ◽

The Impact

Abstract Co-digestion of thermally pre-treated sewage sludge with food waste is an innovative strategy that could improve the balance and availability of nutrients needed to increase the efficiency of anaerobic digestion in terms of biogas production. In this context, the aim of this research was to evaluate the impact of different proportions of sewage sludge/food waste in lab and pilot scale reactors. Special focus was placed on the impact of the variability of food waste composition on the behavior of the pilot digester. Our results show that by adding 40% of co-substrate, a higher biogas production was possible during laboratory operation. Interestingly, using a co-substrate of variable composition had no negative impact on the reactor's stability at pilot scale, promoting an increase in biogas production through a more efficient use of organic matter. In both the lab and pilot experiences there was an impact on the amount of nitrogen in the digestate compared to digester operating in monodigestion. This impact is more significant as the proportion of cosubstrate rises. Overall, our results show that co-digestion of thermally pretreated sewage sludge with food waste allows better management of food waste, especially when their composition is variable.

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Feasibility analysis of print pastes co-disposal in anaerobic sludge digesters

Water Science & Technology ◽

10.2166/wst.1997.0514 ◽

1997 ◽

Vol 36 (2-3) ◽

pp. 181-188

Author(s):

L. Bonomo ◽

A. Rozzi ◽

F. Malpei

Keyword(s):

Sewage Sludge ◽

Industrial Wastewater ◽

Pilot Scale ◽

Treatment Costs ◽

Full Scale ◽

Feasibility Analysis ◽

Anaerobic Sludge ◽

Technical Feasibility ◽

The Future ◽

The Impact

Significant amounts of residual print pastes are produced by the industrial textile settlements of the Como area (Italy). Currently, these wastes are directly discharged in the sewer but it is unlikely that in the future this treatment through POTW will be further allowed. Therefore alternative ways of collection and disposal must be evaluated. The most suitable processes appear to be: drying, followed by incineration or landfilling, or anaerobic co-treatment with sewage sludge. The latter option was investigated at pilot scale and a technical feasibility analysis of the full-scale solution was carried out. Results are presented and discussed with reference to the impact that this solution would have on the performance of POTW and on the treatment costs of textile industrial wastewater.

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Anaerobic co-digestion of sewage sludge and primary clarifier skimmings for increased biogas production

Water Science & Technology ◽

10.2166/wst.2012.550 ◽

2013 ◽

Vol 67 (1) ◽

pp. 174-179 ◽

Cited By ~ 6

Author(s):

S. Alanya ◽

Y. D. Yilmazel ◽

C. Park ◽

J. L. Willis ◽

J. Keaney ◽

...

Keyword(s):

Water Pollution ◽

Sewage Sludge ◽

Pollution Control ◽

Biogas Production ◽

Control Plant ◽

Treatment Plant ◽

Pilot Scale ◽

Water Pollution Control ◽

Study Results ◽

The Impact

The objective of the study was to identify the impact of co-digesting clarifier skimmings on the overall methane generation from the treatment plant and additional energy value of the increased methane production. Biogas production from co-digesting clarifier skimmings and sewage sludge in pilot-scale fed-batch mesophilic anaerobic digesters has been evaluated. The digester was fed with increasing quantities of clarifier skimmings loads: 1.5, 2.6, 3.5 and 7.0 g COD equivalent/(L·d) (COD: chemical oxygen demand). Average volatile solids reduction of 65% was achieved in the scum-fed digester, compared with 51% in the control digester. Average 69% COD removal was achieved at highest scum loading (7 g COD eq/(L·d)) with approximate methane yield of 250 L CH4/kg COD fed (4 ft3/lb COD fed). The results show that scum as co-substrate in anaerobic digestion systems improves biogas yields while a 29% increase in specific CH4 yield could be achieved when scum load is 7 g COD eq/(L·d). Based on the pilot-scale study results and full-scale data from South East Water Pollution Control Plant and Northeast Water Pollution Control Plant the expected annual energy recovery would be approximately 1.7 billion BTUs or nearly 0.5 million kWh.

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Heterotrophic Kinetic Parameter Estimation for Enhanced Biological Phosphorus Removal Processes Operated in Conventional and Membrane-Assisted Modes

Water Quality Research Journal ◽

10.2166/wqrj.2006.008 ◽

2006 ◽

Vol 41 (1) ◽

pp. 72-83 ◽

Cited By ~ 2

Author(s):

Zhe Zhang ◽

Eric R. Hall

Keyword(s):

Parameter Estimation ◽

Phosphorus Removal ◽

Growth Yield ◽

Pilot Scale ◽

Enhanced Biological Phosphorus Removal ◽

Biological Phosphorus Removal ◽

Nitrogen And Phosphorus ◽

Parameter Values ◽

The Impact ◽

Biological Phosphorus

Abstract Parameter estimation and wastewater characterization are crucial for modelling of the membrane enhanced biological phosphorus removal (MEBPR) process. Prior to determining the values of a subset of kinetic and stoichiometric parameters used in ASM No. 2 (ASM2), the carbon, nitrogen and phosphorus fractions of influent wastewater at the University of British Columbia (UBC) pilot plant were characterized. It was found that the UBC wastewater contained fractions of volatile acids (SA), readily fermentable biodegradable COD (SF) and slowly biodegradable COD (XS) that fell within the ASM2 default value ranges. The contents of soluble inert COD (SI) and particulate inert COD (XI) were somewhat higher than ASM2 default values. Mixed liquor samples from pilot-scale MEBPR and conventional enhanced biological phosphorus removal (CEBPR) processes operated under parallel conditions, were then analyzed experimentally to assess the impact of operation in a membrane-assisted mode on the growth yield (YH), decay coefficient (bH) and maximum specific growth rate of heterotrophic biomass (µH). The resulting values for YH, bH and µH were slightly lower for the MEBPR train than for the CEBPR train, but the differences were not statistically significant. It is suggested that MEBPR simulation using ASM2 could be accomplished satisfactorily using parameter values determined for a conventional biological phosphorus removal process, if MEBPR parameter values are not available.

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Dexamethasone-Loaded Nanostructured Lipid Carriers for the Treatment of Dry Eye Disease

Pharmaceutics ◽

10.3390/pharmaceutics13060905 ◽

2021 ◽

Vol 13 (6) ◽

pp. 905

Author(s):

Sangeeta Kumari ◽

Madhuri Dandamudi ◽

Sweta Rani ◽

Elke Behaeghel ◽

Gautam Behl ◽

...

Keyword(s):

Dry Eye ◽

Ocular Surface ◽

Pilot Scale ◽

Dry Eye Disease ◽

Rapid Screening ◽

Eye Disease ◽

Topical Steroids ◽

Nanostructured Lipid Carrier ◽

The Impact ◽

Ophthalmic Formulation

Dry eye disease (DED) or keratoconjunctivitis sicca is a chronic multifactorial disorder of the ocular surface caused by tear film dysfunction. Symptoms include dryness, irritation, discomfort and visual disturbance, and standard treatment includes the use of lubricants and topical steroids. Secondary inflammation plays a prominent role in the development and propagation of this debilitating condition. To address this we have investigated the pilot scale development of an innovative drug delivery system using a dexamethasone-encapsulated cholesterol-Labrafac™ lipophile nanostructured lipid carrier (NLC)-based ophthalmic formulation, which could be developed as an eye drop to treat DED and any associated acute exacerbations. After rapid screening of a range of laboratory scale pre-formulations, the chosen formulation was prepared at pilot scale with a particle size of 19.51 ± 0.5 nm, an encapsulation efficiency of 99.6 ± 0.5%, a PDI of 0.08, and an extended stability of 6 months at 4 °C. This potential ophthalmic formulation was observed to have high tolerability and internalization capacity for human corneal epithelial cells, with similar behavior demonstrated on ex vivo porcine cornea studies, suggesting suitable distribution on the ocular surface. Further, ELISA was used to study the impact of the pilot scale formulation on a range of inflammatory biomarkers. The most successful dexamethasone-loaded NLC showed a 5-fold reduction of TNF-α production over dexamethasone solution alone, with comparable results for MMP-9 and IL-6. The ease of formulation, scalability, performance and biomarker assays suggest that this NLC formulation could be a viable option for the topical treatment of DED.

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Process Modeling and Simulation of Tableting—An Agent-Based Simulation Methodology for Direct Compression

Pharmaceutics ◽

10.3390/pharmaceutics13070996 ◽

2021 ◽

Vol 13 (7) ◽

pp. 996

Author(s):

Niels Lasse Martin ◽

Ann Kathrin Schomberg ◽

Jan Henrik Finke ◽

Tim Gyung-min Abraham ◽

Arno Kwade ◽

...

Keyword(s):

Raw Materials ◽

Pilot Scale ◽

Physical Models ◽

Agent Based Simulation ◽

Validation Data ◽

Agent Based ◽

Industrial Processing ◽

Digital Twins ◽

Product And Process ◽

The Impact

In pharmaceutical manufacturing, the utmost aim is reliably producing high quality products. Simulation approaches allow virtual experiments of processes in the planning phase and the implementation of digital twins in operation. The industrial processing of active pharmaceutical ingredients (APIs) into tablets requires the combination of discrete and continuous sub-processes with complex interdependencies regarding the material structures and characteristics. The API and excipients are mixed, granulated if required, and subsequently tableted. Thereby, the structure as well as the properties of the intermediate and final product are influenced by the raw materials, the parametrized processes and environmental conditions, which are subject to certain fluctuations. In this study, for the first time, an agent-based simulation model is presented, which enables the prediction, tracking, and tracing of resulting structures and properties of the intermediates of an industrial tableting process. Therefore, the methodology for the identification and development of product and process agents in an agent-based simulation is shown. Implemented physical models describe the impact of process parameters on material structures. The tablet production with a pilot scale rotary press is experimentally characterized to provide calibration and validation data. Finally, the simulation results, predicting the final structures, are compared to the experimental data.

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Benchmarking microbiome transformations favors experimental quantitative approaches to address compositionality and sampling depth biases

Nature Communications ◽

10.1038/s41467-021-23821-6 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Verónica Lloréns-Rico ◽

Sara Vieira-Silva ◽

Pedro J. Gonçalves ◽

Gwen Falony ◽

Jeroen Raes

Keyword(s):

Microbial Communities ◽

Quantitative Methods ◽

Microbial Load ◽

Metagenomic Sequencing ◽

Sampling Depth ◽

Microbiome Research ◽

Microbiome Data ◽

The Impact ◽

Analytical Approaches ◽

Quantitative Approaches

AbstractWhile metagenomic sequencing has become the tool of preference to study host-associated microbial communities, downstream analyses and clinical interpretation of microbiome data remains challenging due to the sparsity and compositionality of sequence matrices. Here, we evaluate both computational and experimental approaches proposed to mitigate the impact of these outstanding issues. Generating fecal metagenomes drawn from simulated microbial communities, we benchmark the performance of thirteen commonly used analytical approaches in terms of diversity estimation, identification of taxon-taxon associations, and assessment of taxon-metadata correlations under the challenge of varying microbial ecosystem loads. We find quantitative approaches including experimental procedures to incorporate microbial load variation in downstream analyses to perform significantly better than computational strategies designed to mitigate data compositionality and sparsity, not only improving the identification of true positive associations, but also reducing false positive detection. When analyzing simulated scenarios of low microbial load dysbiosis as observed in inflammatory pathologies, quantitative methods correcting for sampling depth show higher precision compared to uncorrected scaling. Overall, our findings advocate for a wider adoption of experimental quantitative approaches in microbiome research, yet also suggest preferred transformations for specific cases where determination of microbial load of samples is not feasible.

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Optimal Solutions for the Use of Sewage Sludge on Agricultural Lands

Water ◽

10.3390/w13050585 ◽

2021 ◽

Vol 13 (5) ◽

pp. 585

Author(s):

Catalina Iticescu ◽

Puiu-Lucian Georgescu ◽

Maxim Arseni ◽

Adrian Rosu ◽

Mihaela Timofti ◽

...

Keyword(s):

Heavy Metals ◽

Sewage Sludge ◽

Agricultural Production ◽

Agricultural Land ◽

Chemical Characteristics ◽

Optimal Solutions ◽

Physico Chemical ◽

Agricultural Areas ◽

The Impact ◽

Made In

The use of sewage sludge in agriculture decreases the pressure on landfills. In Romania, massive investments have been made in wastewater treatment stations, which have resulted in the accumulation of important quantities of sewage sludge. The presence of these sewage sludges coincides with large areas of degraded agricultural land. The aim of the present article is to identify the best technological combinations meant to solve these problems simultaneously. Adapting the quality and parameters of the sludge to the specificity of the land solves the possible compatibility problems, thus reducing the impact on the environment. The physico-chemical characteristics of the fermented sludge were monitored and optimal solutions for their treatment were suggested so as to allow that the sludge could be used in agriculture according to the characteristics of the soils. The content of heavy metals in the sewage sludge was closely monitored because the use of sewage sludge as a fertilizer does not allow for any increases in the concentrations of these in soils. The article identifies those agricultural areas which are suitable for the use of sludge, as well as ways of correcting some parameters (e.g., pH), which allow the improvement of soil quality and obtained higher agricultural production.

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