SciCombinator

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Concept: Anaerobic

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PURPOSE:: To evaluate the time international canoe polo players spend performing various game activities, measure heart rate (HR) responses during games, and describe the physiological profile of elite players. METHODS:: Eight national canoe polo players were videotaped and wore HR monitors during 3 games at a World Championship and underwent fitness testing. The mean age, height, and weight was 25 ± 1 y, 1.82 ± 0.04 m, and 81.9 ± 10.9 kg, respectively. RESULTS:: Time motion analysis of 3 games indicated that the players spent 29 ± 3% of the game slow/moderate forward paddling, 28 ± 5% contesting, 27 ± 5% resting and gliding, 7 ± 1% turning, 5 ± 1% backwards paddling, 2 ± 1% sprinting, and 2 ± 1% dribbling. Sixty nine (± 20)% of the game time was played at a HR intensity above the HR which corresponded to ventilatory threshold (VT), that was determined during the peak VO2 test. Peak oxygen uptake and VT was 3.3 ± 0.3 and 2.2 ± 0.3 L·min, respectively, on a modified Monark arm crank ergometer. Arm crank peak 5 s anaerobic power was 379 W. CONCLUSION:: The majority of the time spent during international canoe polo games involved slow to moderate forward paddling, contesting for the ball, and resting and gliding. Canoe polo games are played at a high intensity indicated by the HR responses, and the physiological characteristics suggest that these athletes had high levels of upper body aerobic and anaerobic fitness levels.

Concepts: Anaerobic, Ball games, The Players, Game, Canoe polo, VO2 max, Polo, Anaerobic exercise

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Sulfonamides, one of the commonest antibiotics, were widely used on humans and livestock to control pathema and bacterial infections resulting in further environmental risks. The present study evaluated the adsorption and degradation of sulfadiazine (SDZ) and sulfamethoxazole (SMX) in an agricultural soil system under an anaerobic condition. Low sorption coefficients (Kd, 1.22 L kg-1 for SDZ and 1.23 L kg-1 for SMX) obtained from Freundlich isotherms experiment indicated that poor sorption of both antibiotics may pose a high risk to environment due to their high mobility and possibility of entering surface and ground water. Degradation occurred at a lower rate under the anaerobic environment, where both two antibiotics had higher persistence in sterile and non-sterile soils with degradation ratio <75% and DT50 > 20 d. Additionally, the addition of manure slightly increased degradation rates of SDZ and SMX, but there were no significant differences between single and repeated manure application at a later stage (p > 0.05), which suggested that the degradation was affected by both biotic and abiotic factors. Degradation rates would be slower at a higher concentration, indicating that degradation kinetics of SDZ and SMX were dependent on initial concentrations. During the degradation period, the antibiotics removal may change temperature, pH, sulfate and nitrate in soil, which suggested that the variation of antibiotics concentrations was related to the changes of soil physicochemical properties. An equation was proposed to elucidate the link between adsorption and degradation under different conditions, and to predict potential environmental risks of antibiotics.

Concepts: Anaerobic, Manure, Adsorption, Reaction rate, Bacteria, Sulfonamide, Water pollution, Environmental science

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Four slow pyrolyzed biochars produced from wood (WDB), corncobs (CCB), rice husks (RHB) and sawdust (SDB) were evaluated for adsorption, desorption and regeneration of phosphate (PO4(3-)-P) from anaerobically digested liquid swine manure. The PO4(3-)-P adsorption capacity increased followed by initial concentrations increasing. Maximum PO4(3-)-P adsorptions at initial 150 mg/L of PO4(3-)-P (highest load) were average of 7.67, 6.43, 5.73 and 5.41 mg/g for WDB, CCB, RHB and SDB, respectively. Pseudo second order kinetics model could best fit PO4(3-)-P adsorption, which indicated the chemisorption via precipitation was the main mechanism for PO4(3-)-P removal. The sorption process was reversible and the adsorbed PO4(3-)-P could be desorbed in both neutral (57-78%) and acidic solution environments (75-88%) for all biochars. Meanwhile, regenerated biochar could re-adsorb up to 5.62 mg/g at the highest initial PO4(3-)-P of 150 mg/L. The present finding implied biochar could be effectively used to recover PO4(3-)-P from anaerobic digestate.

Concepts: Solution, Manure, Anaerobic filter, Mechanical biological treatment, Digestate, Anaerobic, Anaerobic digestion, Adsorption

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Spent anaerobically digested effluents of agricultural origin were collected and treated using membrane filtration to achieve three-large particle free-nutrient streams of N:P ratios of 16.53, 3.78 and 14.22. Three algal species were grown on these streams, achieving good levels of bioremediation of digester fluids simultaneously with biomass and associated end product formation. Nannochloropsis oceanica and Scenedesmus quadricuada, where proven highly effective in remediating the streams achieving ammonia and phosphate reduction over 60% while for Schizochytrium limacinum SR21 these serve as an ideal production medium for lipids and biomass reaching 16.70w/w% and 1.42gL(-1) correspondingly. These processes thus provide treatment of sludge, avoiding the disposal problems by land spreading. The solid components are nutrient depleted but rich in organic matter as a soil enhancer, while the fluids rich in nutrients can be efficiently utilised for growth to generate high value materials of microalgae facilitating water reclamation.

Concepts: Anaerobic, Biogas, Mechanical biological treatment, Archaea, Digestate, Soil, Sewage treatment, Anaerobic digestion

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To evaluate the effect of anaerobic ammonium oxidation (ANAMMOX) on benzene degradation under denitrification, a sequencing batch reactor (SBR) under denitrification synergized with ANAMMOX (SBR-DenAna) for benzene degradation was established by inoculating anaerobic ammonium-oxidizing bacteria (AnAOB) into a SBR under denitrification reactor (SBR-Den) for benzene degradation. The average rate of benzene degradation and the maximum first-order kinetic constant in SBR-DenAna were 2.34- and 1.41-fold those in SBR-Den, respectively, indicating that ANAMMOX improved the degradation of benzene under denitrification synergized with ANAMMOX. However, the average rate of benzene degradation decreased by 35% in the denitrification-ANAMMOX synergistic reactor when 10 mg N L(-1) NO2(-) was added; the rate recovered once NO2(-) was depleted, indicating that ANAMMOX might detoxify NO2(-). Results from high-throughput sequencing analysis revealed that Azoarcus within the family Rhodocyclaceae might be associated with benzene degradation in the two SBRs. AnAOB affiliated with the family Candidatus Brocadiaceae were just detected in SBR-DenAna.

Concepts: Anaerobic, Environmental microbiology, Metabolism, Biotechnology, Denitrification, Microbiology, Nitrogen, Bacteria

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The feasibility of using anaerobic ammonium oxidation (anammox) process to treat industrial wastewater containing thiocyanate (SCN(-)) was examined in this study. Anammox activity decreased with increasing thiocyanate concentration and pre-exposure time in batch tests. A typical noncompetitive model was used to fit the data for thiocyanate inhibition, and the 50% inhibition concentration (IC50) of thiocyanate on anammox was 620.4mgL(-1) at 200mgL(-1) total nitrogen level. The influent thiocyanate concentration of test reactor (R1) in phase II gradually increased from 10 to 120mgL(-1), and the average nitrogen removal efficiency (NRE) of R1 was maintained at 83.0±7.82%. This robustness was attributed to the self-adaptation ability of anammox biomass through long-term acclimatization. The NRE was decreased to 57.1% under 130mgL(-1) thiocyanate within two days. However, the NRE of control reactor (R0) in absence of thiocyanate was 91.23±4.11% in this phase. Under thiocyanate stress, the specific anammox activity, settling velocity and heme c content of the granules significantly decreased, and the extracellular polymeric substances content slightly increased. The short- and long-term performance inhibition could be reversed in the presence of 10mgL(-1) Fe(III).

Concepts: Control theory, Velocity, Wastewater, Electrochemistry, Anaerobic, Chemical engineering, Denitrification, Nitrogen

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Cinnabar dissolution is an important factor controlling mercury (Hg) cycling. Recent studies have suggested the co-occurrence of re-adsorption of the released Hg during the course of cinnabar dissolution. However, there is a lack of feasible techniques that can quantitatively assess the amount of Hg re-adsorbed on cinnabar when investigating cinnabar dissolution. In this study, a new method, based on isotope tracing and dilution techniques, was developed to study the role of Hg re-adsorption in cinnabar dissolution. The developed method includes two key components: (1) accurate measurement of both released and spiked Hg in aqueous phase and (2) estimation of re-adsorbed Hg on cinnabar surface via the reduction in spiked (202)Hg(2+). By adopting the developed method, it was found that the released Hg for trials purged with oxygen could reach several hundred μgL(-1), while no significant cinnabar dissolution was detected under anaerobic condition. Cinnabar dissolution rate when considering Hg re-adsorption was approximately 2 times the value calculated solely with the Hg detected in the aqueous phase. These results suggest that ignoring the Hg re-adsorption process can significantly underestimate the importance of cinnabar dissolution, highlighting the necessity of applying the developed method in future cinnabar dissolution studies.

Concepts: Estimation, Mercury, Adoption, Anaerobic filter, ACCURATE, Anaerobic, Suggestion, Evaluation

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The effect of salinity on the anaerobic ammonium oxidation (ANAMMOX) process in a UASB reactor was investigated by analysing ammonium, nitrite, nitrate and TN concentrations, and TN removal efficiency. Extracellular polymeric substances (EPSs) and specific ANAMMOX activity (SAA) were evaluated. Results showed the effluent deteriorated after salinity was increased from 8 to 13 g/L and from 13 to 18 g/L, and TN removal efficiency decreased from 80% to 30% and 80% to 50%, respectively. However, ANAMMOX performance recovered and TN removal efficiency increased to 80% after 40 days when the influent concentrations of [Formula: see text] and [Formula: see text] were 200 mg/L and salinity levels were at 13 and 18 g/L, respectively. The amount of EPSs decreased from 58.9 to 37.1 mg/g volatile suspended solids (VSS) when the reactor was shocked by salinity of 13 g/L, and then increased to 57.2 mg/g VSS when the reactor recovered and ran stably at 13 g/L. The amount of EPSs decreased from 57.2 to 49.1 mg/g VSS when the reactor was shocked by salinity of 18 g/L, and then increased to 60.7 mg/g VSS when the reactor recovered and ran stably at 18 g/L. The amount of EPS and the amounts of polysaccharide, protein and humus showed no evident difference when the reactor recovered from different levels of salinity shocks. Batch tests showed salinity shock load from 8 to 38 g/L inhibited the SAA. However, when the reactor recovered from salinity shocks, SAA was higher compared to that when the reactor was subjected to the same level of salinity shock.

Concepts: Anaerobic, Ion, Ammonia, Stability, Upflow anaerobic sludge blanket digestion, Electrochemistry, Shock

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Foam accumulation in deep-pit manure storage facilities is of concern for swine producers because of the logistical and safety-related problems it creates. A feeding trial was performed to evaluate the impact of feed grind size, fiber source, and manure inoculation on foaming characteristics. Animals were fed: (1) C-SBM (corn-soybean meal): (2) C-DDGS (corn-dried distiller grains with solubles); and (3) C-Soybean Hull (corn-soybean meal with soybean hulls) with each diet ground to either fine (374μm) or coarse (631μm) particle size. Two sets of 24 pigs were fed and their manure collected. Factors that decreased feed digestibility (larger grind size and increased fiber content) resulted in increased solids loading to the manure, greater foaming characteristics, more particles in the critical particle size range (2-25μm), and a greater biological activity/potential.

Concepts: Kingston upon Hull, Anaerobic, Foam, Pig, Particle, Particle physics, Manure, Anaerobic digestion

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Desmodesmus sp. was used in anaerobically digested wastewater (ADW) for nutrients removal and the biodiesel production was measured and compared using fed-batch cultivation was investigated and compared with batch cultivation. The Desmodesmus sp. was able to remove 236.143, 268.238 and 6.427mg/L of TN, NH4-N and PO4-P respectively after 40d of fed-batch cultivation, while in batch cultivation the quantities of TN, NH4-N and PO4-P removed were 33.331, 37.227 and 1.323mg/L. Biomass production of Desmodesmus sp. was also enhanced in fed-batch cultivation, when ADW loading was carried out every 2days; the biomass concentration peaked at 1.039g/L, which was three times higher than that obtained in batch cultivation (0.385g/L). The highest lipid production (261.8mg/L) was also recorded in fed-batch cultivation as compared to batch cultivation (83.3mg/L). Fed-batch cultivation of Desmodesmus sp. could provide effective control of nutrients limitation and/or ammonia inhibition on microalgae cultivation.

Concepts: Anaerobic, Sewage, Biogas, Sewage treatment, Anaerobic digestion