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Journal of Environmental Management Apr 2024Digestate processing is a strategy to improve the management of digestate from biogas plants. Solid-liquid separation is usually the primary step and can be followed by... (Review)
Review
Digestate processing is a strategy to improve the management of digestate from biogas plants. Solid-liquid separation is usually the primary step and can be followed by advanced treatments of the fractions. The knowledge about the performance of the separators and the quality of the fractions is scattered because of many available techniques and large variability in digestate characteristics. We performed a systematic review and found 175 observations of full-scale solid-liquid separation of digestate. We identified 4 separator groups, 4 digestate classes based on substrate, and distinguished whether chemical conditioners were used. We confirmed the hypothesis that the dominant substrate can affect the efficiency of the digestate separation. Furthermore, the results showed that centrifuges separated significantly more dry matter and total P than screw presses. Use of chemical conditioners in combination with a centrifuge lowered the dry matter concentration in the liquid fraction by 30%. Screw presses consumed 4.5 times less energy than centrifuges and delivered 3.3 tonne ammonium N in the liquid fraction and 0.3 tonne total P in the solid fraction using 1 MWh. The results can provide data for systems analyses of biogas solutions and can support practitioners when choosing among full-scale separator techniques depending on the digestate type. In a broader perspective, this work contributes to the continuous improvement of biogas plants operations and to their role as nutrients recovery sites.
Topics: Anaerobiosis; Biofuels
PubMed: 38508011
DOI: 10.1016/j.jenvman.2024.120585 -
PloS One 2024Locomotor profiling using anaerobic speed reserve (ASR) enables insights into athletes' physiological and neuromuscular contributing factors and prescription of...
Assessing anaerobic speed reserve: A systematic review on the validity and reliability of methods to determine maximal aerobic speed and maximal sprinting speed in running-based sports.
PURPOSE
Locomotor profiling using anaerobic speed reserve (ASR) enables insights into athletes' physiological and neuromuscular contributing factors and prescription of high-intensity training beyond maximal aerobic speed (MAS). This systematic review aimed to determine the validity and reliability of different methods to assess the characteristics of ASR, i.e., MAS and maximal sprinting speed (MSS).
METHODS
A comprehensive search of the PubMed and Web of Science databases was conducted according to the PRISMA guidelines. Studies were included if they reported data on validity and/or reliability for methods to assess MAS or MSS.
RESULTS
58 studies were included with 28 studies referring to MAS and 30 studies to MSS. Regarding MAS, different methods for cardiopulmonary exercise testing yielded different values (four out of seven studies) of MAS (Cohen's d (ES) = 0.83-2.8; Pearson's r/intraclass correlation coefficient (r/ICC) = 0.46-0.85). Criterion validity of different field tests showed heterogeneous results (ES = 0-3.57; r/ICC = 0.40-0.96). Intraday and interday reliability was mostly acceptable for the investigated methods (ICC/r>0.76; CV<16.9%). Regarding MSS, radar and laser measurements (one out of one studies), timing gates (two out of two studies), and video analysis showed mostly good criterion validity (two out of two studies) (ES = 0.02-0.53; r/ICC = 0.93-0.98) and reliability (r/ICC>0.83; CV<2.43%). Criterion validity (ES = 0.02-7.11) and reliability (r/ICC = 0.14-0.97; CV = 0.7-9.77%) for global or local positioning systems (seven out of nine studies) and treadmill sprinting (one out of one studies) was not acceptable in most studies.
CONCLUSION
The criterion validity of incremental field tests or shuttle runs to examine MAS cannot be confirmed. Results on time trials indicate that distances adapted to the participants' sporting background, fitness, or sex might be suitable to estimate MAS. Regarding MSS, only sprints with radar or laser measures, timing gates, or video analysis provide valid and reliable results for linear sprints of 20 to 70 m.
Topics: Humans; Anaerobiosis; Reproducibility of Results; Athletes; Exercise; Running
PubMed: 38252665
DOI: 10.1371/journal.pone.0296866 -
Journal of Environmental Management Dec 2023Anaerobic digestion (AD) as a waste management strategy for the organic fraction of municipal waste (OFMSW) has received attention in developed countries for several...
Anaerobic digestion (AD) as a waste management strategy for the organic fraction of municipal waste (OFMSW) has received attention in developed countries for several decades, leading to the development of large-scale plants. In contrast, AD of OFMSW has only recently drawn attention in developing countries. This systematic review was carried out to investigate the implementation of AD to treat the OFMSW in developing countries, focusing on assessing pilot and full-scale AD plants reported in the last ten years. Studies that met the selection criteria were analyzed and data regarding operating parameters, feedstock characteristics, and biogas, digestate, and energy production were extracted. As outlined in this systematic review, AD plants located in developing countries are mostly one-stage mesophilic systems that treat OFMSW via mono-digestion, almost exclusively with the aim of producing electrical energy. Based on the analysis done throughout this systematic review, it was noted that there is a large difference in the maturity level of AD systems between developing and developed countries, mainly due to the economic capacity of developed countries to invest in sustainable waste management systems. However, the number of AD plants reported in scientific papers is significantly lower than the number of installed AD systems. Research articles regarding large-scale implementation of AD to treat OFMSW in developed countries were analyzed and compared with developing countries. This comparison identified practices used in plants in developed countries that could be utilized in the large-scale implementation and success of AD in developing countries. These practices include exploiting potential products with high market-values, forming partnerships with local industries to use industrial wastes as co-substrates, and exploring different biological and physical pretreatment technologies. Additionally, the analysis of capital and operational costs of AD plants showed that costs tend to be higher for developing countries due to their need to import of materials and equipment from developed countries. Technical, economical, and political challenges for the implementation of AD at a large-scale in developing countries are highlighted.
Topics: Solid Waste; Refuse Disposal; Anaerobiosis; Developing Countries; Bioreactors; Biofuels; Methane
PubMed: 37751665
DOI: 10.1016/j.jenvman.2023.118993 -
Revista Espanola de Quimioterapia :... Apr 2023The objective of this study was to perform a systematic review of the characteristics, causative microorganisms and outcome of brain abscesses caused by anaerobic...
The objective of this study was to perform a systematic review of the characteristics, causative microorganisms and outcome of brain abscesses caused by anaerobic bacteria over the past 25 years. We reviewed studies on brain abscesses which included infection due to anaerobic microorganisms published between 1998 and 2022. We excluded reports with polymicrobial infections (more than 2 anaerobic bacteria isolated) and those that do not provide enough information to make comparisons, the reports with only one case of brain abscess due to anaerobes, as well as those focused on an only anaerobic bacterium. Also, we have excluded the cases in pediatric population. We searched the scientific literature through the Cochrane Library, EMBASE and PubMed/MEDLINE databases for studies of this condition. We finally included 28 studies with 6,167 patients, of which 715 (11.5%) were cases caused by anaerobic bacteria. There was a male predominance (70%) and mean age of 40.3 years. Most infections were monomicrobial (59.4%). The most common anaerobic microorganisms isolated were Bacteroides spp (43.4%) and Gram-positive anaerobic cocci (35.1%). Cases of brain abscesses caused by anaerobic bacteria were most frequent in Asia and Europe. The source of infection most frequent was otogenic in 84.6% followed by a neurosurgery procedure infection in 23% of patients. The main symptom observed was headache in 95.6% of patients followed by fever (69.5%). Surgical treatment was performed in 48 % of patients and the percentage of patients in whom antibiotic treatment was applied range 88.8% to 100%. The main limitation of this review is the non-inclusion of studies published before of 1998 in which MALDI-TOF MS system had not been introduced in the majority of laboratories for routine identification. The patient rate with isolation of anaerobic bacteria in brain abscesses is low, but these data could be underestimated mainly due to the fastidious nature of these microorganisms and the difficulties in the identification of some anaerobes.
Topics: Humans; Male; Child; Adult; Female; Anaerobiosis; Base Composition; Phylogeny; RNA, Ribosomal, 16S; Sequence Analysis, DNA; Brain Abscess; Bacteria, Anaerobic; Gram-Positive Cocci
PubMed: 36733997
DOI: 10.37201/req/114.2022 -
Environmental Research Feb 2023In recent years, the demand for high-quality biofuels from renewable sources has become an aspirational goal to offer a clean environment by alternating the depleting... (Review)
Review
In recent years, the demand for high-quality biofuels from renewable sources has become an aspirational goal to offer a clean environment by alternating the depleting fossil fuels to meet future energy needs. In this aspect, biohythane production from wastes has received extensive research interest since it contains superior fuel characteristics than the promising conventional biofuel i.e. biogas. The main aim is to promote research and potentials of biohythane production by a systematic review of scientific literature on the biohythane production pathways, substrate/microbial consortium suitability, reactor design, and influential process/operational factors. Reactor configuration also decides the product yield in addition to other key factors like waste composition, temperature, pH, retention time and loading rates. Hence, a detailed emphasis on different reactor configurations with respect to the type of feedstock has also been given. The technical challenges are highlighted towards process optimization and system scale up. Meanwhile, solutions to improve product yield, technoeconomics, applications and key policy and governance factors to build a hydrogen based society have also been discussed.
Topics: Fermentation; Anaerobiosis; Hydrogen; Biofuels; Microbial Consortia
PubMed: 36535394
DOI: 10.1016/j.envres.2022.115094 -
Bioresource Technology Feb 2023Ammonium oxidation coupled to Fe(III) reduction (Feammox) is a newly discovered iron-nitrogen cycle process of microbial catalyzed NH oxidation coupled with iron... (Review)
Review
Ammonium oxidation coupled to Fe(III) reduction (Feammox) is a newly discovered iron-nitrogen cycle process of microbial catalyzed NH oxidation coupled with iron reduction. Fe(III) often exists in the form of insoluble iron minerals resulting in reduced microbial availability and low efficiency of Feammox. Electron shuttles(ESs) can be reversibly oxidized and reduced which has the potential to improve Feammox efficiency. This review summarizes the discovery process, electron transfer mechanism, influencing factors and driven microorganisms of Feammox, ang expounds the possibility and potential mechanism of ESs to enhance Feammox efficiency. Based on an in-depth analysis of the current research situation of Feammox for nitrogen removal, the knowledge gaps and future research directions including how to apply ESs enhanced Feammox to promote nitrogen removal in practical wastewater treatment have been highlighted. This review can provide new ideas for the engineering application research of Feammox and strong theoretical support for its development.
Topics: Ferric Compounds; Electrons; Anaerobiosis; Iron; Nitrogen Cycle; Ammonium Compounds; Oxidation-Reduction; Nitrogen; Denitrification
PubMed: 36526117
DOI: 10.1016/j.biortech.2022.128495 -
Waste Management (New York, N.Y.) Feb 2023With the continuous rise of food waste (FW) throughout the world, a research effort to reveal its potential for bioenergy production is surging. There is a lack of... (Review)
Review
With the continuous rise of food waste (FW) throughout the world, a research effort to reveal its potential for bioenergy production is surging. There is a lack of harmonized information and publications available that evaluate the state-of-advance for FW-derived methane production process, particularly from an engineering and sustainability point of view. Anaerobic digestion (AD) has shown remarkable efficiency in the bioconversion of FW to methane. This paper reviews the current research progress, gaps, and prospects in pre-AD, AD, and post-AD processes of FW-derived methane production. Briefly, the review highlights innovative FW collection and optimization routes such as AI that enable efficient FW valorization processes. As weather changes and the FW sources may affect the AD efficiency, it is important to assess the spatio-seasonal variations and microphysical properties of the FW to be valorized. In that case, developing weather-resistant bioreactors and cost-effective mechanisms to modify the raw substrate morphology is necessary. An AI-guided reactor could have high performance when the internal environment of the centralized operation is monitored in real-time and not susceptible to changes in FW variety. Monitoring solvent degradation and fugitive gases during biogas purification is a challenging task, especially for large-scale plants. Furthermore, this review links scientific evidence in the field with full-scale case studies from different countries. It also highlights the potential contribution of ADFW to carbon neutrality efforts. Regarding future research needs, in addition to the smart collection scheme, attention should be paid to the management and utilization of FW impurities, to ensure sustainable AD operations.
Topics: Methane; Food; Anaerobiosis; Refuse Disposal; Bioreactors; Biofuels
PubMed: 36493662
DOI: 10.1016/j.wasman.2022.11.030 -
Journal of Environmental Management Oct 2022As food waste gets acknowledged as a global potential source of biomass, its valorization through anaerobic digestion becomes an attractive strategy. This work describes... (Review)
Review
As food waste gets acknowledged as a global potential source of biomass, its valorization through anaerobic digestion becomes an attractive strategy. This work describes the state-of-the-art on the valorization of food waste by anaerobic digestion and the optimization of the process. The methodology used was a bibliometric and systematic review of the optimization of the process from 66 articles selected. Bibliometric mapping allowed us to identify that, until now, most studies have been focused on the: i) anaerobic co-digestion strategy in order to stabilize the process, ii) interest in the generation of biofuels to replace non-renewable fuels, iii) study of metabolic processes for a better understanding of the system iv) reactor design optimization and others facilities to increase process efficiency. The systematic analysis showed that the operational parameters has been extensively studied to optimize the process. Therefore, co-digestion has been the main strategy to improve the process. In this sense, knowledge of the substrate and co-substrate is extremely important to operate the reactors. For methane production, the ideal operating conditions indicated were: pH of 7, solids content between 4.0 and 15%, C/N ratio of 25, hydraulic retention time from 25 to 40 days and alkalinity from 2850 to 2970.5mgCaCO/L. In addition, the ideal OLR will vary mainly according to operating temperature, number of reactor stages, and raw material characteristics. This review indicates trends and knowledge gaps that are important to guide new research on the anaerobic digestion of food waste, pointing out the potential advantages, optimization strategies, by-products of interest and challenges of the process. The results were used for the development of references of ideal operating conditions for energy production, being able to guide the design and operation of reactors.
Topics: Anaerobiosis; Bibliometrics; Biofuels; Bioreactors; Food; Methane; Refuse Disposal
PubMed: 35932740
DOI: 10.1016/j.jenvman.2022.115763 -
Sleep & Breathing = Schlaf & Atmung Jun 2023Circadian rhythm affects maximal short-term performance, and it is an important determinant of the training component. This review aimed to summarise the influence of... (Review)
Review
PURPOSE
Circadian rhythm affects maximal short-term performance, and it is an important determinant of the training component. This review aimed to summarise the influence of circadian rhythm on peak and mean power output of muscle, fatigue index, and blood lactate levels.
METHODS
English language articles were searched through the following databases: PubMed, Web of Science, Science Direct, and Google Scholar, and pertinent randomized control trials were scrutinized.
RESULTS
The search revealed 17,481 articles, and 29 were included in this systematic review based on inclusion and exclusion criteria. Randomized control trials were selected, and the methodological validity of articles was evaluated using the 'Cochrane risk of bias tool'. Findings suggest that outcome variables muscle peak power output (p < 0.0001, Z = 7.22, I = 57.42, SMD = - 0.91, 95% confidence interval CI = - 1.16, - 0.67), muscle mean power output (p < 0.0001, Z = 5.66, I = 83.85, SMD = - 0.75, 95% CI = - 1.01, - 0.49), and fatigue index (p = 0.02, Z = 2.41, I = 2.49, SMD = - 0.39, 95% CI = - 0.72, - 0.07) were higher in the evening while the level of blood lactate was higher in the morning (p = 0.79, Z = 0.27, I = 0.73, SMD = - 0.05, 95% CI = - 0.46, - 0.35).
CONCLUSION
The results show that diurnal variation affects both peak and mean power output of muscle as well as fatigue index. However, there is no remarkable effect of circadian rhythm on blood lactate level. A major factor attributed to this finding was the variation in the training experience of participants. For an effective training prescription, it is very important to consider the effect of the biological clock on muscle power output since anaerobic exercise performance is discernibly influenced by the time of the day.
Topics: Humans; Anaerobiosis; Circadian Rhythm; Fatigue; Lactates
PubMed: 35904663
DOI: 10.1007/s11325-022-02662-7 -
Scandinavian Journal of Medicine &... May 2022The effects of short sprint interval training (sSIT) with efforts of ≤10 s on maximal oxygen consumption (V̇O max), aerobic and anaerobic performances remain... (Meta-Analysis)
Meta-Analysis Review
The effects of short sprint interval training (sSIT) with efforts of ≤10 s on maximal oxygen consumption (V̇O max), aerobic and anaerobic performances remain unknown. To verify the effectiveness of sSIT in physically active adults and athletes, a systematic literature search was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). The databases PubMed/MEDLINE, ISI Web of Science, and SPORTDiscus were systematically searched on May 9, 2020, and updated on September 14, 2021. Inclusion criteria were based on PICO and included healthy athletes and active adults of any sex (≤40 years), performing supervised sSIT (≤10 s of "all-out" and non-"all-out" efforts) of at least 2 weeks, with a minimum of 6 sessions. As a comparator, a non-sSIT control group, another high-intensity interval training (HIIT) group, or a continuous training (CT) group were required. A total of 18 studies were deemed eligible. The estimated SMDs based on the random-effects model were -0.56 (95% CI: -0.79, -0.33, p < 0.001) for V̇O max, -0.43 (95% CI: -0.67, -0.20, p < 0.001) for aerobic performance, and -0.44 (95% CI: -0.70, -0.18, p < 0.001) for anaerobic performance after sSIT vs. no exercise/usual training. However, there were no significant differences (p > 0.05) for all outcomes when comparing sSIT vs. HIIT/CT. Our findings indicate a very high effectiveness of sSIT protocols in different exercise modes (e.g., cycling, running, paddling, and punching) to improve V̇O max, aerobic, and anaerobic performances in physically active young healthy adults and athletes.
Topics: Adult; Anaerobiosis; Exercise Test; High-Intensity Interval Training; Humans; Oxygen Consumption; Running
PubMed: 35090181
DOI: 10.1111/sms.14133