The production of K*(892)0 and $\phi$(1020) resonances has been measured in p-Pb collisions at $\sqrt{s_{NN}}$ = 8.16 TeV using the ALICE detector. Resonances are reconstructed via their hadronic ...decay channels in the rapidity interval -0.5 < y < 0 and the transverse momentum spectra are measured for various multiplicity classes up to pT = 20 GeV/c for K*(892)0 and pT = 16 GeV/c for $\phi$(1020). The pT-integrated yields and mean transverse momenta are reported and compared with previous results in pp, p-Pb and Pb-Pb collisions. The xT scaling for K*(892)0 and $\phi$(1020) resonance production is newly tested in p-Pb collisions and found to hold in the high-pT region at Large Hadron Collider energies. The nuclear modification factors (RpPb) as a function of pT for K*0 and $\phi$ at $\sqrt{s_{NN}}$ = 8.16 TeV are presented along with the new RpPb measurements of K*0, $\phi$, Ξ, and Ω at $\sqrt{s_{NN}}$ = 5.02 TeV. At intermediate pT (2–8 GeV/c), RpPb of Ξ, Ω show a Cronin-like enhancement, while K*0 and $\phi$ show no or little nuclear modification. At high pT (>8 GeV/c), the RpPb values of all hadrons are consistent with unity within uncertainties. The RpPb of K*(892)0 and $\phi$(1020) at $\sqrt{s_{NN}}$ = 8.16 and 5.02 TeV show no significant energy dependence.
BRIEF: Computing a Local Binary Descriptor Very Fast Calonder, M.; Lepetit, V.; Ozuysal, M. ...
IEEE transactions on pattern analysis and machine intelligence,
07/2012, Letnik:
34, Številka:
7
Journal Article
Recenzirano
Odprti dostop
Binary descriptors are becoming increasingly popular as a means to compare feature points very fast while requiring comparatively small amounts of memory. The typical approach to creating them is to ...first compute floating-point ones, using an algorithm such as SIFT, and then to binarize them. In this paper, we show that we can directly compute a binary descriptor, which we call BRIEF, on the basis of simple intensity difference tests. As a result, BRIEF is very fast both to build and to match. We compare it against SURF and SIFT on standard benchmarks and show that it yields comparable recognition accuracy, while running in an almost vanishing fraction of the time required by either.
Perfluorooctane sulfonate (PFOS) is a highly recalcitrant perfluoro chemical belonging to the family of per- and polyfluoroalkyl substances (PFAS). Its adsorption and degradation was demonstrated in ...a novel PFAS remediation process involving the adsorption onto graphite intercalated compounds (GIC) and the electrochemical oxidation. The Langmuir type of adsorption was characterized by a loading capacity of 53.9 μg PFOS g−1 GIC and a second order kinetics (0.021 g μg−1 min−1). Up to 99% of PFOS was degraded in the process with a half-life of 15 min. The breakdown by-products included short chain perfluoroalkane sulfonates such as Perfluoroheptanesulfonate (PFHpS), Perfluorohexanesulfonate (PFHxS), Perfluoropentanesulfonate (PFPeS) and Perfluorobutanesulfonate (PFBS), but also short chain perfluoro carboxylic acids such as perfluorooctanoic acid (PFOA), perfluorohexanoic acid (PFHxA) and perfluorobutanoic acid (PFBA) indicating different degradation pathways. These by-products could also be broken down but the shorter the chain the slower the degradation rate. This novel combined adsorption and electrochemical process offers an alternative treatment for PFAS contaminated waters.
NOM = natural organic matter. Photo of graphite flakes reprinted from Electrochimica Acta Vol 135, K. Nkrumah-Amoako, E. P.L. Roberts, N.W. Brown, S.M. Holmes, The effects of anodic treatment on the surface chemistry of a Graphite Intercalation Compound, Page 569, Copyright (2023), with permission from Elsevier. Schematics of interaction reproduced from J. of Hazardous Materials Vol. 274, Z. Du, S. Deng, Y. Bei, Q. Huang, B. Wang, J. Huang, G. Yu, Adsorption behavior and mechanism of perfluorinated compounds on various adsorbents—A review, Pages 450 and 451, Copyright (2023), with permission from Elsevier. Display omitted
•Novel combined adsorption and electrochemical oxidation of PFOS was described.•PFOS can be adsorbed with an adsorption capacity of 53.9 μg PFOS/g GIC.•By-products include smaller chain perfluoroalkane sulfonates and carboxylic acids.•Up to 99% PFOS removal after 40 min at a current of 0.5 A•By-products can be also broken down but require longer time and at least 1.7 A
The stability and performance of a two-stage anaerobic membrane process was investigated at different organic loading rates (OLRs) and Hydraulic Retention Times (HRTs) over 200 days. The Hydrolytic ...Reactor (HR) was fed with the Organic Fraction of Municipal Solid Waste (OFMSW), while the leachate from the HR was fed continuously to two Submerged Anaerobic Membrane Bioreactors (SAMBR1 and 2). The Total COD (TCOD) of the leachate varied over a wide range, typically between 4000 and 26,000
mg/L while the Soluble COD (SCOD) in the permeate was in the range 400–600
mg/L, achieving a COD removal greater than 90% at a HRT of 1.6–2.3 days in SAMBR1. The operation was not sustainable below this HRT due to a membrane flux limitation at 0.5–0.8
L/m
2
h (LMH), which was linked to the increasing MLTSS. SCOD in the recycled permeate did not build up indicating a slow degradation of recalcitrants over time. SAMBR2 was run in parallel with SAMBR1 but its permeate was treated aerobically in an Aerobic Membrane Bioreactor (AMBR). The AMBR acted as a COD-polishing and ammonia removal step. About 26% of the recalcitrant SCOD from SAMBR2 could be aerobically degraded in the AMBR. In addition, 97.7 % of the ammonia–nitrogen was converted to nitrate in the AMBR at a maximum nitrogen-loading rate of 0.18
kg NH
4
+–N/m
3
day. GC–MS analysis was performed on the reactor effluents to determine their composition and what compounds were recalcitrant.
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•Electrochemical oxidation of pharmaceutical-contaminated wastewater.•Reaction mechanisms for electrooxidation are outlined.•Systematic optimisation of operating parameters for anodic ...oxidation technology.•Future research and development of novel electrode materials are discussed.
Pharmaceutical contaminants are emerging pollutants of concern that pose significant risks to human health and the environment. Adsorption has become increasingly significant in recent years due to its high removal efficiency of non-biodegradable pharmaceutical contaminants. Adsorption process is relatively simple and easy to operate, effectively removing pharmaceutical contaminants from wastewater without incurring significant capital costs. On the other hand, electrochemical oxidation technology is one of the most critical electrochemical advanced oxidation processes (EAOPs) to degrade pharmaceutical compounds in wastewater. It has been proven effective in treating natural wastewater containing pharmaceutical contaminants. When combined with adsorption technology, it can improve the techno-economic feasibility and environmental viability, especially for an industrial-scale pharmaceutical wastewater treatment process. The challenges of treating pharmaceutical residues in complex wastewater are due to its resistance to biodegradation in conventional wastewater treatment plants. However, the benefits of combining multiple treatment processes can lead to high removal efficiency of pharmaceutical pollutants, minimise energy consumption and eliminate the use of unnecessary chemical reagents. Most importantly, this review emphasises the optimisation of process variables for maximising the degradation efficiency of pharmaceutical pollutants. Finally, the future perspectives of combined technologies were discussed to provide new recommendations for future research directions.
Perfluorooctanoic acid (PFOA) is a bioaccumulative synthetic chemical containing strong C–F bonds and is one of the most common per- and polyfluoroalkyl substances (PFAS) detected in the environment. ...Graphite intercalated compound (GIC) flakes were used to adsorb and degrade PFOA through electrochemical oxidation. The adsorption followed the Langmuir model with a loading capacity of 2.6 µg PFOA g
−1
GIC and a second-order kinetics (3.354 g µg
−1
min
−1
). 99.4% of PFOA was removed by the process with a half-life of 15 min. When PFOA molecules broke down, they released various by-products, such as short-chain perfluoro carboxylic acids like PFHpA, PFHxA, and PFBA. This breakdown indicates the cleavage of the perfluorocarbon chain and the release of CF
2
units, suggesting a transformation or degradation of the original compound into these smaller acids. Shorter-chain perfluorinated compounds had slower degradation rates compared to longer-chain ones. Combining these two methods (adsorption and in situ electrochemical oxidation) was found to be advantageous because adsorption can initially concentrate the PFOA molecules, making it easier for the electrochemical process to target and degrade them. The electrochemical process can potentially break down or transform the PFAS compounds into less harmful substances through oxidation or other reactions.
•SAMBRs can operate at very low HRTs (1h), and are very tolerant to hydraulic shocks.•SMP were 14±2mgCOD/L (feed 544mg/L) at steady state, but fluctuated during shocks.•GC–MS with solid phase ...extraction identified 120 compounds in the SAMBR effluent.•Microbially produced N-butyl-benzenesulfonamide/cyclooctasulfur found during shocks.
This study investigated the performance of a submerged anaerobic membrane bioreactor (SAMBR) fed with synthetic wastewater (544±22mgCOD/L) operating at different hydraulic retention times (HRTs-12h, 8h, 6h, 4h, 2h, and 1h) at both steady state, and under transient load conditions (2 and 1h), and the SMPs produced under these conditions. COD removal at decreasing HRTs (12h, 8h, 6h, 4h, and 2h) was high (>94%), but decreased to 80% when operating at 1h HRT. VFAs accumulated when the HRT was decreased to 2h and 1h, accounting for 69% and 89% of the effluent COD, respectively. Effluent SMPs accounted for an average of 14±2mgCOD/L at steady state, but this fluctuated more during transient conditions (12±6mgCOD/L). The COD equivalent of dissolved methane in the effluent was 17% at 4h HRT, exceeding the saturation value of methane. Low MW compounds were identified using gas chromatography–mass spectrometry (GC–MS), with solid phase extraction (SPE) as the pre-treatment. 120 compounds were identified in the effluent at steady state, and were alkanes (39), alkenes (3), esters (11), alcohols (7), nitrogenated compounds (11), phenols (11), and others (9). Increases in cyclooctasulfur, N-butyl-benzenesulfonamide, alkanes, 1-naphthalenol, camphor, 2-methylphenol, and (Z)-9-octadecenamide were also found during transient conditions, and these compounds were not found in the feed; hence it is possible that these compounds were produced by microorganism as by-products from substrate utilization.
This study focused on three of the most studied PFAS molecules, namely perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA) and perfluorobutane sulfonate (PFBS). They were compared in ...terms of their adsorption capacity onto graphite intercalated compound (GIC), a low surface area, highly conductive and cheap adsorbent. The adsorption on GIC followed a pseudo second order kinetics and the maximum adsorption capacity using Langmuir was 53.9 μg/g for PFOS, 22.3 μg/g for PFOA and 0.985 μg/g for PFBS due to electrostatic attraction and hydrophobic interactions. GIC was added into an electrochemical oxidation reactor and >100 μg/L PFOS was found to be fully degraded (<10 ng/L) leaving degradation by-products such as PFHpS, PFHxS, PFPeS, PFBS, PFOA, PFHxA and PFBA below 100 ng/L after 5 cycles of adsorption onto GIC for 20 min followed by regeneration at 28 mA/cm2 for 10 min. PFBS was completely removed due to degradation by aqueous electrons on GIC flakes. Up to 98 % PFOA was removed by the process after 3 cycles of adsorption onto GIC for 20 min followed by regeneration at 25 mA/cm2 for 10 min. When PFBS was spiked individually, only 17 % was removed due to poor adsorption on GIC. There was a drop of 3–40 % by treating PFOS, PFOA and smaller sulfonates in a real water matrix under the same electrochemical conditions (20 mA/cm2), but PFOS and PFOA removal percentage were 95 and 68 % after 20 min at 20 mA/cm2.
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•>100 μg/L PFOS was fully degraded at a current density of 28 mA/cm2.•Up to 98 % PFOA (C0 = 45 μg/L) was degraded at 25 mA/cm2.•PFBS could not be adsorbed on GIC and degraded.•Loss of 3–40 % efficiency when using real water matrix under similar condition•95 and 68 % PFOS and PFOA removal at 28 mA/cm2 for 20 min in real water
•Landfill leachate was treated in a Submerged Anaerobic Membrane BioReactor.•More than 90% COD removal was obtained at an HRT of 0.4–0.6days.•Monohydrocalcite precipitated on the membrane causing ...flux drop.•Hydroxyapatite precipitated in the aerobic polishing step.
The treatment of leachate (Average TCOD=11.97g/L, 14.4% soluble) from the organic fraction of municipal solid waste was investigated using a Submerged Anaerobic Membrane BioReactor (SAMBR), followed by an aerobic membrane bioreactor (AMBR) to polish this effluent. This paper investigated the exact nature and composition of the inorganic precipitate in each of the reactors in the process. The flux decreased due to precipitation of calcium as monohydrocalcite (CaCO3·H2O) containing traces of metals onto the SAMBR membrane because of high CO2 partial pressures. Precipitation of calcium in the AMBR was also observed due to a higher pH. In this case, phosphorus also precipitated with calcium in two different phases: the background layer contained calcium, oxygen, carbon and small amounts of phosphorus (2–6.7%), while flakes containing calcium, oxygen and higher amounts of phosphorus (10–17%) were probably hydroxyapatite (Ca5(PO4)3OH).
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