Carbon dioxide miscible flooding has been proven to be one of the most effective enhanced oil recovery (EOR) technologies, particularly for light and medium oil reservoirs. However, specific effects of pore structure on CO2 miscible flooding recovery in low permeability reservoir lack in-depth understandings. In this paper, pore structures are specifically studied by means of the molecular mechanics to evaluate their effects on the CO2 EOR in the low permeability reservoir. First, a series lab experiments are performed for the pore and fluid characterization. More specifically, the pore throat size and distribution frequency are measured from the high-pressure mercury injection and nuclear magnetic resonance. The minimum miscibility pressure is determined from the slim-tube tests with known oil compositions tested from gas chromatography analysis. Second, the regularity of CO2 extraction is explored on the basis of molecular mechanics and the thickness of raffinate is calculated. Finally, the raffinate volume and recovery ratio in the pores are calculated after the CO2 miscible flooding. The results show that a raffinate-layer with thickness of 0.13 μm remains on the surface of the pore after the CO2 miscible flooding, which would cause the oil to be immobile since the throat could be blocked when the throat radius is smaller than 0.26 μm. The recoveries of cores C-1 and C-2 are 70.1 % and 61.4 % from calculations and 68.4 % and 59.8 % from experiments, whose errors are 2.5 % and 2.7 %, respectively. This study would be beneficial to analyze the CO2 miscible flooding in reservoirs with different pore structures and provide technical support for improving CO2 utilization efficiency.
Fe3(PO4)2·8H2O (Vivianite) is one of the potential phosphorus recovery products from wastewater treatment plant (WWTP). In this study, we first discovered that vivianite can effectively photoactivate peroxodisulfate (PDS) to produce some reactive oxygen species (ROS) for tetracycline antibiotics (TCs) degradation. The results demonstrated that vivianite could efficiently activate PDS to achieve 100% removal of TCs under LED UV light (UVL), visible light (VL) or real solar light (SL) irradiation within 10 min, respectively. More importantly, ca. 80%, 78% and 40%∼58% of TOC removal efficiencies were achieved under UVL, VL and SL irradiation within 30 min, respectively. As well, toxicological simulation and antibacterial studies showed that the aquatic toxicity of the TCs intermediates was lower than those of the original TCs. This work provided new insights into the application of photoactivated sulfate radical-advanced oxidation process (SR-AOP) for organic pollutants degradation over vivianite, which may encourage the recovery and utilization of vivianite in the wastewater treatment process.
Drinking alcohol is cited as a way for men to cope with stress, with most of the research emanating from western countries. However, in the East, limited scientific research has been conducted on the relationship between stress and alcohol consumption. Thus, this study aimed to explore the influence of life stress on alcohol use among Chinese men.Our data were drawn from the 2012 China Family Panel Studies that comprised representative samples of the Chinese population. In total, 15,373 Chinese men participated in this study, and their weekly alcohol intake and life stress were evaluated using computer assisted personal interviews. It was found that the greater the overall life pressure experienced by the Chinese men, the less likely they were to engage in both general (OR = 0.977) and heavy drinking (OR = 0.975). Although severe life stress that interfered with daily life did not affect general drinking, it had a negative effect on heavy drinking. As for less severe life stresses, feeling down and sad had an inhibitory effect on male general and heavy drinking, and experiencing loneliness had a similar effect on general drinking but no effect on heavy drinking. Further, perceiving unfriendliness from others had no influence on male drinking behavior. Although feeling disliked by others had no effect on male drinking behavior, it had a significant, positive effect on male heavy drinking. This study found that in China, stress did not increase male alcohol consumption, but rather, inhibited it. Alcohol consumption is not a preferred strategy for Chinese men dealing with stress.
In this study, the previously overlooked effects of contaminants’ molecular structure on their degradation efficiencies and dominant reactive oxygen species (ROS) in advanced oxidation processes (AOPs) are investigated with a peroxymonosulfate (PMS) activation system selected as the typical AOP system. Averagely, degradation efficiencies of 19 contaminants are discrepant in the CoCaAl-LDO/PMS system with production of SO4•–, •OH, and 1O2. Density functional theory calculations indicated that compounds with high EHOMO, low-energy gap (ΔE = ELUMO – EHOMO), and low vertical ionization potential are more vulnerable to be attacked. Further analysis disclosed that the dominant ROS was the same one when treating similar types of contaminants, namely SO4•–, 1O2, 1O2, and •OH for the degradation of CBZ-like compounds, SAs, bisphenol, and triazine compounds, respectively. This phenomenon may be caused by the contaminants’ structures especially the commonly shared or basic parent structures which can affect their effective reaction time and second-order rate constants with ROS, thus influencing the contribution of each ROS during its degradation. Overall, the new insights gained in this study provide a basis for designing more effective AOPs to improve their practical application in wastewater treatment.
Abstract We performed a cross-sectional survey of 2143 female students in a university in Tianjin, China regarding perceived air quality (PAQ) and sick building syndrome (SBS) symptoms in the student dormitory. The prevalence of general, mucosal, and skin symptoms was 22.1%, 21.9%, and 26.3%, respectively. The three most prevalent PAQ complaints were ?dry air? (48.9% often), ?stuffy odor? (18.2%), and ?other unpleasant odors? (5.1%), and they were significant risk factors for 11?12 out of 12 SBS symptoms (adjusted odds ratios [AOR]: 1.6?5.8). Survey data of 1471 undergraduates, whose dorms were of uniform layout and furnishing, were used to further investigate the influences of occupancy level and occupant behaviors on PAQ and SBS symptoms. Frequent use of air freshener/perfume was a significant risk factor for ?dry air,? less frequent room cleaning and higher occupancy density were significant risk factors for ?stuffy odor,? and less natural ventilation was a significant risk factor for both ?stuffy odor? and ?pungent odor.? These factors were also significantly associated with some SBS symptoms. In particular, the use of air freshener/perfume exhibited a significant dose?response pattern with ?fatigue? (sometimes: AOR 1.3; often: AOR 2.0) and with ?irritated, stuffy, or runny nose? (sometimes: AOR 1.6; often: AOR 2.2).
Current research focuses on introducing additional energy or reducing agents to directly accelerate the formation of Fe(IV) and Fe(V) from ferrate (Fe(VI)), thereby ameliorating the oxidation activity of Fe(VI). Interestingly, this study discovers that colloid manganese dioxide (cMnO2) can remarkably promote Fe(VI) to remove various contaminants via a novel surface-promoted pathway. Many lines of evidence suggest that high-valent Fe species are the primary active oxidants in the cMnO2−Fe(VI) system, however, the underlying activation mechanism for the direct reduction of Fe(VI) by cMnO2 to generate Fe(IV)/Fe(V) is eliminated. Further analysis found that Fe(VI) can combine with the vacancies in cMnO2 to form precursor complex (cMnO2−Fe(VI)*), which possesses a higher oxidation potential than Fe(VI). This makes cMnO2−Fe(VI)* is more vigorous to oxidize pollutants with electron-rich moieties through the electron transfer step than alone Fe(VI), resulting in producing Fe(V) and Fe(IV). The products of Fe(VI) decay (i.e., Fe(II), Fe(III), and H2O2) are revealed to play vital roles in further boosting the formation of Fe(IV) and Fe(V). Most importantly, the catalytic stability of cMnO2 in complicated waters is superior to popular reductants, suggesting its outstanding application potential. Taken together, this work provides a full-scale insight into the surface-promoted mechanism in Fe(VI) oxidation process, thus providing an efficient and green strategy for Fe(VI) activation.
The high-throughput production of the eco-friendly MIL-88A(Fe) was achieved under mild reaction conditions with normal pressure and temperature. The as-prepared MIL-88A(Fe) exhibited efficient photo-Fenton catalytic ofloxacin (OFL) degradation upon visible light irradiation with good stability and reusability. The OFL (20.0 mg/L) was completely degraded within 50 min under visible light with the aid of MIL-88A(Fe) (0.25 g/L) and H2O2 (1.0 mL/L) in aqueous solution (pH = 7.0). The hydroxyl radicals (·OH) are the main active species during the photo-Fenton oxidation process. Meanwhile, the degradation intermediates and the corresponding degradation pathways were identified and proposed with the aid of both ultra-high performance liquid chromatography tandem quadrupole time-of-flight mass spectrometry (UHPLC-Q-TOF-MS) and density functional theory (DFT) calculations. Finally, the degradation product library was firstly established to identify intermediate transformation products (TPs) with their variation of concentration, and their corresponding toxicologic activities were assessed via Toxtree and T.E.S.T software as well. Finally, the MIL-88A is efficient and stable with four cycles’ catalysis operations, demonstrating good potential for water treatment.
Nitrate (NO3−) is a ubiquitous contaminant in water and wastewater. Conventional treatment processes such as adsorption and membrane separation suffer from low selectivity for NO3− removal, causing high energy consumption and adsorbents usage. In this study, we demonstrate selective removal of NO3− in an electrosorption process by a thin, porous carbonized eggshell membrane (CESM) derived from eggshell bio-waste. The CESM possesses an interconnected hierarchical pore structure with pore size ranging from a few nanometers to tens of micrometers. When utilized as anode in an electrosorption process, the CESM exhibited strong selectivity for NO3− over Cl−, SO42−, and H2PO4−. Adsorption of NO3− by the CESM reached 2.4 × 10−3 mmol/m2, almost two orders of magnitude higher than that by activated carbon (AC). More importantly, the CESM achieved NO3−/Cl− selectivity of 7.79 at an applied voltage of 1.2 V, the highest NO3−/Cl− selectivity value reported to date. The high selectivity led to a five-fold reduction in energy consumption for NO3− removal compared to electrosorption using conventional AC electrodes. Density function theory calculation suggests that the high NO3− selectivity of CESM is attributed to its rich nitrogen-containing functional groups, which possess higher binding energy with NO3− compared to Cl−, SO42−, and H2PO4−. These results suggest that nitrogen-rich biomaterials are good precursors for NO3− selective electrodes; similar chemistry can also be used in other materials to achieve NO3− selectivity.
This work demonstrates the successful immobilization of MIL-88A(Fe) MOF on cotton fibers to fabricate MIL-88A(Fe)/cotton fibers (MC) by an eco-friendly method. The prepared MC is used to activate peroxydisulfate for eliminating multiple tetracycline antibiotics, such as oxytetracycline (OTC), tetracycline (TTC), and chlortetracycline (CTC) in simulated wastewater under UV-light irradiation. The photoactivated sulfate radical-advanced oxidation processes (SR-AOPs) towards the removal of tetracycline antibiotics matrix (initial concentration of 10.0 mg/L) using MC were initially investigated using a batch method. The results reveal that 97.5% OTC, 95.2% TTC, and 100.0% CTC can be degraded in the MC/UV/PDS system in the presence of 2 g/L of MC and 1 mM of PDS. The degradation pathways of OTC, TTC, and CTC were clarified via liquid chromatography-mass spectrometry analysis and DFT calculations. The quantitative structure–activity relationship analysis shows that the tetracycline antibiotics are transformed into their corresponding intermediates with lower toxicity within 8.0 min. A self-designed fixed bed reactor, in which the MC was packed into the annular channel, was adopted to test the long-term operation possibility of the MC in the continuous photoactivated SR-AOP system. The findings demonstrate that the whole antibiotics matrix can be removed completely within 22 h. This work is the first to demonstrate the use of MOFs as catalysts for SR-AOP to achieve continuous purification of simulated wastewater. The findings highlight a new possibility for the use of MOFs in large-scale wastewater treatment over.
Phase transitions can occur in certain materials such as transition metal oxides (TMOs) and chalcogenides when there is a change in external conditions such as temperature and pressure. Along with phase transitions in these phase change materials (PCMs) come dramatic contrasts in various physical properties, which can be engineered to manipulate electrons, photons, polaritons, and phonons at the nanoscale, offering new opportunities for reconfigurable, active nanodevices. In this review, we particularly discuss phase-transition-enabled active nanotechnologies in nonvolatile electrical memory, tunable metamaterials, and metasurfaces for manipulation of both free-space photons and in-plane polaritons, and multifunctional emissivity control in the infrared (IR) spectrum. The fundamentals of PCMs are first introduced to explain the origins and principles of phase transitions. Thereafter, we discuss multiphysical nanodevices for electronic, photonic, and thermal management, attesting to the broad applications and exciting promises of PCMs. Emerging trends and valuable applications in all-optical neuromorphic devices, thermal data storage, and encryption are outlined in the end.
In this study, magnetic iron-nickel sulfides biochar composites (MINBs) were successfully prepared via one-step solvothermal method and applied to Cr(VI)-containing wastewater treatment. X-ray diffraction (XRD) and scanning electron microscopy (SEM) revealed that synthesized iron-nickel sulfides anchored and dispersed on biochar surface. Cr(VI) removal efficiency and capacity by MINB-5 (molar ratio of Ni to Fe was 5%) were more than 97% and 24.8 mg g-1 within 20 min respectively, when the initial concentration of Cr(VI) was 20 mg L-1. Effects of different operational parameters on Cr(VI) removal efficiency were investigated, including molar ratio of Ni to Fe, dosage of catalyst, initial concentration of Cr(VI), pH value of solution, coexisting ions, natural organic matters (NOMs) and temperature. X-ray photoelectron spectroscopy (XPS) and flame atomic absorption spectrometric (FAAS) analysis demonstrated that Cr(VI) was removed through reduction process by Fe(Ⅱ), which was released from MINBs. Persistent free radicals (PFRs) of biochar, Ni(Ⅱ) and S(-Ⅱ) in MINBs jointly accelerated Fe(Ⅱ)/Fe(III) circulation, instead of direct reduction of Cr(VI) directly. These novel findings provide a new prospect of application of magnetic iron-nickel sulfides biochar composites for Cr(VI)-polluted wastewater remediation.
The hepatoma cell lines stably expressing sodium taurocholate cotransporting polypeptide (NTCP), the receptor of hepatitis B virus (HBV) infection, serve as important infection models for studying viral biology and drug discovery. However, the efficiency of infection greatly varies. In this study, we studied the effects and potential mechanisms of Matrigel® hESC-qualified (M-hq), a biological basement membrane matrix commonly used in cell culture, on promotion HBV in vitro infection in HepG2-NTCP cells. For the first time, our findings demonstrate that M-hq could enhance the infection efficiency of cell culture-derived HBV with no impact on the cell viability, the HBV transcription and response to antiviral treatments. The infection enhancement is reproducible and is suggested to occur at HBV attachment step. Our study suggests that this novel system is applicable for studying HBV biology and new drugs.