Anaerobic Recovery Research Articles

Anaerobic recovery of vivianite from waste-activated sludge through combined sludge pre-fermentation and agroforestry biomass-based biochar

The recovery of vivianite through the anaerobic digestion of waste-activated sludge has attracted considerable attention due to its operational simplicity and the high economic value of vivianite. This study concentrated on the recovery of vivianite from anaerobic fermentation systems through a strategy combining sludge pre-fermentation with the waste agricultural and forestry biomass-derived biochar (ZBC). In-depth analyses of the structure and functionality of ZBC were conducted using techniques such as Fourier-transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy. The sediment produced after the experiment and the changes in microbial community composition were characterized. The results indicated that pre-fermentation promoted phosphorus release, enhancing the synthesis of vivianite while selectively enriching respiratory and fermentative Fe (III)-reducing microorganisms. When FeOOH was used as the Fe (III) source, ZBC, through its dual action of redox functional groups and graphitization structure, increased the Fe2+ production by 243.6 % in the system dominated by respiratory Fe (III)-reducing bacteria. The optimal dosage of ZBC for the simultaneous recovery of vivianite resources and methane energy was 2.5 g/L. The combined application of pre-fermentation and ZBC provides a novel approach for the efficient recycling of vivianite and offers new insights into the reuse of agroforestry waste biomass resources.

Application Prospect of Anaerobic Reduction Pathways in Acidithiobacillus ferrooxidans for Mine Tailings Disposal: A Review

The accumulation of mine tailings on Earth, generated from the extraction, processing, and utilization of mineral resources, is a serious environmental challenge. The importance of the recovery of valuable elements and rare-earth elements, together with the economic benefits of precious and base metals, is a strong incentive to develop sustainable methods to recover metals from tailings. Currently, researchers are attempting to improve the efficiency of valuable elements and rare-earth elements recovery from tailings using bioleaching, a more sustainable method compared to traditional methods. In this work, we report the research status of the application of Acidithiobacillus ferrooxidans (At. ferrooxidans) anaerobic reduction in tailings disposal. Recent advances in the anaerobic characteristics of At. ferrooxidans recovery process and technical difficulties are further described. We found that current research has made significant progress in anaerobic recovery. This is of great significance for the development of bioleaching technologies and industrial production of heavy metals in tailings. Finally, based on the perspectives and directions of this review, the present study can act as an important reference for the academic participants involved in this promising field.

The potential benefits of assessing post-cardiopulmonary exercise testing (CPET) in aging: a narrative review

Cardiopulmonary exercise testing (CPET) is an important tool to measure the cardiopulmonary fitness of an individual and has been widely used in athletic, clinical and research settings. Most CPET focus on analyzing physiological responses during exercise. We contend that the post-CPET recovery physiological responses offer further diagnostic and prognostic information about the health of the cardiopulmonary and metabolic systems, especially when testing apparently healthy middle-aged and older adults. However, there are limited studies that investigate physiological responses during the post-CPET recovery, and even less so in middle-aged and older adults. Therefore, this current review is aimed at discussing the contribution of post-CPET recovery parameters to cardiopulmonary health and their potential applications in aging populations. In addition to the existing methods, we propose to examine the aerobic and anaerobic recovery threshold post-CPET as novel potential diagnostic and/or prognostic tools.

Best Practices for the Pre-Analytic Phase of Anaerobic Bacteriology

Anaerobic bacteria that cause infections contribute to patient morbidity and mortality, especially among patients with underlying conditions or who are immunocompromised. While once largely grouped together without specific differentiation, anaerobic bacteria, defined as organisms that utilize terminal electron acceptors other than oxygen, are of increasing importance in clinical microbiology. In this review, we discuss pre-analytical-phase best practices for anaerobic recovery in the clinical microbiology laboratory. The suspected infection, and in turn the type of specimen to be cultured, helps determine which sample container, specimen collection method, transport conditions, and culture media are needed for optimal recovery of anaerobic bacteria.

Alkaline Thermal Hydrolysis of Sludge: Browning Reactions and Their Influence on Anaerobic Digestion and Protein Recovery

Alkaline Thermal Hydrolysis of Sludge: Browning Reactions and Their Influence on Anaerobic Digestion and Protein Recovery

Inhibitory Effect of Salinity and Humic Acid on the Performance of Anaerobic Ammonium Oxidation Process and Recovery of Anammox Activity

The anaerobic ammonium oxidation (Anammox) process can effectively treat the landfill leachate. However, the influences of complex components in landfill leachate on anammox bacteria were insuffici...

Does circadian rhythm have an impact on anaerobic performance, recovery and muscle damage?

ABSTRACT This study aimed to examine the effect of circadian rhythms (CR) on anaerobic performance and subsequent recovery, muscle damage, and respiratory muscle strength. Twenty diurnally active male football players (age, 22.20 ± 3.14 y) were asked to perform the Wingate anaerobic power test three times for 30 s each at 09:00, 14:00 and 19:00 h, with a minimum recovery period of 1 week between each testing day. Pretest oral temperature, respiratory muscle strength, oxygen saturation, and rating of perceived exertion were recorded at three different time of the day. To examine post-exercise recovery, heart rate (HR) and lactic acid (LA) levels were recorded before and after the tests. Blood samples were collected 20 min after each test to assess muscle damage. The body temperature taken at 19:00 h was the highest of the three (p < .01). After the tests, the LA value at 19:00 h was higher than that at 09:00 h (p < .05). According to CR, the HR values measured after anaerobic exercise were higher at 14:00 h (p < .05). The peak power value was higher at 14:00 h than at 19:00 h (p < .058). CR does not affect muscle damage and respiratory muscle strength. Further, at 14:00 h, anaerobic power was higher and recovery occurred faster compared to the other test times of 09:00 and 19:00 h. Therefore, it is recommended that anaerobic training should be performed early in the afternoon.

Association of heart rate and heart rate variability with an anaerobic performance test and recovery of Brazilian jiu-jitsu athletes

ABSTRACT Recovery in the intervals between high-intensity efforts is associated with high heart rate variability (HRV) in sports. The current study analysed the association of heart rate (HR) and HRV with performance in a specific test for Brazilian jiu-jitsu athletes (JJAPT) and the HR recovery (HRR). Twenty Brazilian jiu-jitsu (BJJ) male athletes (aged: 18 to 45 years, 1.76 ± 0.07 m, 82.6 ± 12.6 kg), graduated from white to black belt, underwent HRV analysis at rest and the JJAPT. The number of repetitions in each set, fatigue index, power drop, and HR were recorded. Repeated measures ANOVA and the Bonferroni post hoc test were used to analyse performance. Multivariate linear regression analysis and the Spearman rank correlation test were used to detect associations between performance and age, BMI, time of BJJ practice, HR, and HRV indices. HR and HRV indices did not demonstrate associations with performance in the JJAPT. Performance showed moderate correlations with BMI (r = −0.50, p = 0.02), HRpeak (r = −0.47, p = 0.03), HRRset4 (r = −0.48, p = 0.03), and HRRset5 (r = −0.47, p = 0.03). HR was correlated with anaerobic performance. However, HRV indices had little impact on recovery between sets.

Effects of suggested speed endurance training program in a number biochemical variables after anaerobic effort and recovery for advanced short distance runners

Effects of suggested speed endurance training program in a number biochemical variables after anaerobic effort and recovery for advanced short distance runners

Sulfate and metals removal from acid mine drainage in a horizontal anaerobic immobilized biomass (HAIB) reactor

The acid mine drainage (AMD) can causes negative impacts to the environment. Physico-chemical methods to treat AMD can have high operational costs. Through passive biological methods, such as anaerobic reactors, sulfate reduction, and recovery of metals are promoted. This study evaluated the performance of a horizontal anaerobic immobilized biomass (HAIB) reactor for the treatment of synthetic AMD using polyurethane foam as support material, and anaerobic sludge as inoculum. Ethanol was used as an electron donor for sulfate reduction, resulting in an influent chemical oxygen demand (COD) in the range of 500–1,500 mg/L and COD/sulfate ratio at 1. A gradual increase of sulfate and COD concentration was applied that resulted in COD removal efficiencies higher than 78%, and sulfate removal efficiencies of 80%. Higher sulfate and COD concentrations associated with higher hydraulic retention times (36 h) proved to be a better strategy for sulfate removal. The HAIB reactor was able to accommodate an increase in the SLR up to 2.25 g SO42−/L d−1 which achieved the greatest performance on the entire process. Moreover, the reactor proved a suitable alternative for reaching high levels of metal removal (86.95 for Zn, 98.79% for Fe, and 99.59% for Cu).

Effect of antiseptic gels in the microbiologic colonization of the suture threads after oral surgery

Three different bioadhesive gels were evaluated in a double-blind randomized clinical trial in which microbial growth in the suture thread was assessed following post-surgical application of the aforementioned gels. Also assessed in this trial were, the intensity of post-surgical pain as well as the degree of healing of the patients’ surgical wounds. A total of 21 patients (with 42 wisdom teeth) participated in this trial. Chlorhexidine gel, chlorhexidine-chitosan gel, and hyaluronic acid gel were evaluated, with a neutral water-based gel serving as the control agent. The aerobic and facultative anaerobic bacterial recovery on blood agar was lower in the placebo group than in the experimental groups. The most significant difference (p = 0.04) was observed in the chlorhexidine-chitosan group. in which the growth of Blood Agar and Mitis Salivarius Agar was significantly higher than in the placebo group. The intensity of post-surgical pain was very similar among all the groups. Significantly better healing rates were observed in the patients treated with chlorhexidine-chitosan gel when compared with those who used the placebo gel (p = 0.03), and in particular when compared with those patients who used hyaluronic acid gel (p = 0.01). Through our microbiological analyses, we were able to conclude that none of the bioadhesive gels tested resulted in beneficial reductions in the bacterial/fungal populations. However, the healing rates of patients who were treated with chlorhexidine-chitosan were better than those of the patients who used either the placebo gel or the hyaluronic acid gel.

Model-based optimisation and economic analysis to quantify the viability and profitability of an integrated nutrient and energy recovery treatment train

In order to hasten the implementation of optimal, cost-effective and sustainable treatment trains for resource recovery from biowaste, a new nutrient recovery model (NRM) library has been developed and validated at steady state. It includes physico-biochemical mathematical models for anaerobic digestion, struvite precipitation and ammonia stripping and absorption as ammonium sulfate. The present paper describes the use of the NRM library to establish the operational settings of a sustainable and cost-effective treatment scenario with maximal resource (nutrients and biogas) recovery and minimal energy and chemical requirements. Under the optimised conditions and assumptions made, potential financial benefits for a large-scale anaerobic digestion and nutrient recovery project treating 2700 m3/d of pig manure were estimated at US$2·8–6·5/m3 based on net variable cost calculations, or an average of ∼$2/(m3 year), equivalent to $40/(t total solids year), over 20 years in the best case when also taking into account capital costs. Hence, it is likely that in practice a full-scale zero-cost biorefinery for nutrient and energy recovery from manure can be constructed. As such, this paper demonstrates the potential of the NRM library to facilitate the implementation of sustainable nutrient and energy (biogas) recovery treatment trains for biowaste valorisation.

Effect of arginine supplementation on footballers’ anaerobic performance and recovery

Background: The use of supplements has increased in recent years. L-arginine is popular supplement in athletes and this supplement stimulates nitric oxide which purpose to increase sports performance. Aims: This study aims to determine the effects of L-arginine supplement on anaerobic performance and recovery. Materials and Methods: 28 male active football players who play in amateur leagues, get training regularly, between the ages of 18 and 30 participated the study. The subjects were randomly assigned to experimental and placebo group. During 14 days, experimental group consumed 6 grams of arginine and the placebo group consumed 6 grams of wheat bran. Both before and after the supplementation anthropometric, biochemical and anaerobic capacity levels were measured. In order to search recovery after the anaerobic test, the level of Lactic Acid (LA) and Heart Rate (HR) were observed up until the 10th minute of recovery. Results: The research results suggest that after supplementation, the experimental group’s body mass index (BMI) decreased compared to pre-supplementation (Pre= 23,60±2,28kg/m2 vs. Post= 23,39±2,12kg/m2)(p<0.05). On the other hand, the anaerobic performance measurements of both groups do not demonstrate any statistically significant difference before and after supplementation. The post supplementation recovery LA levels showed more rapid reduction from 5th min up to 10th min in experimental group. After the supplementation, 1st minute recovery HR levels were lower than pre in both groups but the experimental group experienced a higher decrease than placebo group. This suggests that suplementation of arginine helps to excrete LA from the body. The comparison of the HR values measured before and after the 14 day long supplementation period shows that both the experimental and the placebo groups experienced a decrease in the resting HR values as well as the HR values during the 1st minute of recovery. The experimental group experienced a higher decrease. After 14 day supplementation Aspartat Aminotransferaz (AST), Alanin Aminotransferaz ALT and Laktat Dehidrogenaz (LDH) (LDH; Pre= 229,41±47,23 vs. Post= 176.08±45.62) levels significantly decreased compared to the pre-supplementation in arginine group (p<0.05). Conclusion: Consequently, the findings suggest that supplementation of L-Arginine accelerates the excretion of lactic acid from the body and decreases the amount of fat in the body. It also rapidly recovers the muscle injuries caused by the decrease in LDH enzyme levels after training and has a positive impact on anaerobic performance. Finally, it accelerates recovery.

Impacts of varying durations of passive oxygen exposure on freshwater denitrifier community structure and function

Fertilizer use has dramatically increased the availability of nitrate (NO3 −) in aquatic systems. Microbe-mediated denitrification is one of the predominant means of NO3 − removal from freshwaters, yet oxygenation (O2)-induced disruptions—e.g., extreme precipitation events—can occur, resulting in a disproportional increase in nitrous oxide (N2O) production and efflux as facultative anaerobic bacterial populations use of O2 as a terminal electron acceptor increases. We examined the effects of 12- and 24-h passive O2 exposure on previously anaerobic bacterial communities focusing on denitrification enzyme activity (DEA), N2O production, and bacterial community 16S rRNA and nitrous oxide reductase gene (nosZ) profiles after 12, 24, and 48 h of anaerobic recovery. Treatments experiencing 24-h O2 exposure had significantly higher DEA 12 h into anaerobic recovery than treatments undergoing 12-h O2 exposure. Initial N2O emissions were significantly lower in the 24-h O2 exposure treatments although by 24 h a dramatic spike (tenfold relative to the 12-h O2 exposure treatments) in N2O concentrations was observed. However, within 6 h (30-h anaerobic recovery) these differences were gone. Community nosZ profiles experiencing 24-h O2 exposure exhibited reduced diversity after 24-h recovery, which corresponded with an increase in N2O emissions. However, after 48 h of anaerobic recovery, nosZ diversity had recovered. These observations highlight the effects of short-term aerobic disruption on denitrification, as well as the effects on the denitrifier community profile. Together, these data suggest that recovery to ambient N cycling is exacerbated by disturbance length due to increased lag time and subsequent loss of denitrifier community diversity.

The Effects of Calf"s Compression Garments on Maximal Anaerobic Power, Muscle Pain, and Recovery during and post Cycling

The Effects of Calf"s Compression Garments on Maximal Anaerobic Power, Muscle Pain, and Recovery during and post Cycling

Effects of kinesio taping on anaerobic power recovery after eccentric exercise

ABSTRACTThe aim of the study was to evaluate the effectiveness of kinesio taping (KT) in anaerobic power recovery after eccentric exercise. The study was carried out on 10 healthy men. The participants performed two 60-min downhill runs with a constant intensity. Peak anaerobic power (PP) and mean power (MP) were measured before and five times after eccentric exercise. Anaerobic power was evaluated with the Maximal Cycling Sprint Test. After the downhill run, passive recovery (PR) and KT (lymphatic application) were applied in random order. A significant decrease in PP and MP was observed at least for 24 h after PR, compared to baseline. After the KT application 24 h after eccentric exercises, anaerobic power was already similar to the baseline measurement. The application of KT significantly improved anaerobic power recovery time after eccentric exercise compared to the period of passive rest immediately prior to testing.

Hemerythrins in the microaerophilic bacterium Campylobacter jejuni help protect key iron–sulphur cluster enzymes from oxidative damage

Microaerophilic bacteria are adapted to low oxygen environments, but the mechanisms by which their growth in air is inhibited are not well understood. The citric acid cycle in the microaerophilic pathogen Campylobacter jejuni is potentially vulnerable, as it employs pyruvate and 2-oxoglutarate:acceptor oxidoreductases (Por and Oor), which contain labile (4Fe-4S) centres. Here, we show that both enzymes are rapidly inactivated after exposure of cells to a fully aerobic environment. We investigated the mechanisms that might protect enzyme activity and identify a role for the hemerythrin HerA (Cj0241). A herA mutant exhibits an aerobic growth defect and reduced Por and Oor activities after exposure to 21% (v/v) oxygen. Slow anaerobic recovery of these activities after oxygen damage was observed, but at similar rates in both wild-type and herA strains, suggesting the role of HerA is to prevent Fe-S cluster damage, rather than promote repair. Another hemerythrin (HerB; Cj1224) also plays a protective role. Purified HerA and HerB exhibited optical absorption, ligand binding and resonance Raman spectra typical of μ-oxo-bridged di-iron containing hemerythrins. We conclude that oxygen lability and poor repair of Por and Oor are major contributors to microaerophily in C. jejuni; hemerythrins help prevent enzyme damage microaerobically or during oxygen transients.

The relation between running speed parameter at anaerobic threshold and recovery in elite soccer players

The relation between running speed parameter at anaerobic threshold and recovery in elite soccer players

The Effects of Warm-up and Cool-down Intensity on Anaerobic Maximal Exercise and Recovery after Exercise

The Effects of Warm-up and Cool-down Intensity on Anaerobic Maximal Exercise and Recovery after Exercise

Anaerobic Digestion and Energy Recovery from Food Waste

Anaerobic Digestion and Energy Recovery from Food Waste