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This work presents mechanisms to rationalize the nature of ultrafast photochemical and photophysical processes on the first singlet metal-ligand charge transfer state (1MLCT1) of the [Ru(bpy)3]2+ complex. The 1MLCT1 state is the lowest-lying singlet excited state and the most important intermediate in the early evolution of photoexcited [Ru(bpy)3]2+*. The results obtained from simple but interpretable theoretical models show that the 1MLCT1 state can be very quickly formed via both direct photo-excitation and internal conversions and then can efficiently relax to its equilibrium geometry in ca. 5 fs. The interligand electron transfer (ILET) on the potential energy surface of the 1MLCT1 state is also extremely fast, with a rate constant of ca. 1.38 × 1013 s-1. The ultrafast ILET implies that the excited electron can dynamically delocalize over the three bpy ligands, despite the fact that the excited electron may be localized on either one of the three ligands at the equilibrium geometries of the three symmetric equivalent minima. Since rapid ILET essentially suggests delocalization, the long-standing controversy in inorganic photophysics-whether the excited electron is localized or delocalized-may therefore be calmed down to some extent.
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Conventional electrochemical activation of peroxymonosulfate (PMS) is not very cost-effective and practical by the excessive input of energy. The electricity generated by photosynthetic microalgae fuel cells (MFCs) is utilized to activate PMS, which would achieve the combination of green bioelectricity and advanced oxidation processes for sustainable pollutants degradation. In this study, a novel dual-chamber of MFCs was constructed by using microalgae as anode electron donor and PMS as cathode electron acceptor, which was operating under both close-circuit and open-circuit conditions. Under close-circuit condition, 1-12 mM PMS in cathode was successfully in situ activated, where 32.00%-99.83% of SMX was removed within 24 h, which was about 1.21-1.78 times of that in the open-circuit of MFCs. Meanwhile, a significant increase in bioelectricity generation in MFCs was observed after the accumulation of microalgae biomass (4.65-5.37 mg/L), which was attributed to the efficient electron separation and transfer. Furthermore, the electrochemical analysis demonstrated that SMX or its products were functioned as electronic shuttles, facilitating the electrochemical reaction and altering the electrical capacitance. The quenching experiments and voltage output results reflected that complex active radical (SO4â -, â OH, and 1O2) were involved in SMX removal. Seven degradation products of SMX were detected and S-N bond cleavage was the main degradation pathway. Predicted toxicity values calculated by ECOSAR program showed that all the products were less toxic or nontoxic. Finally, the density functional theory (DFT) calculations revealed that the O and N atoms on SMX were more susceptible to electrophilic reactions, which were more vulnerable to be attacked by reactive species. This study provided new insights into the activation of PMS by bioelectricity for SMX degradation, proposing the mechanisms for PMS activation and degradation sites of SMX.
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Fontes de Energia Bioelétrica , Sulfametoxazol , Poluentes Químicos da Água , Poluentes Químicos da Água/química , Sulfametoxazol/química , Peróxidos/química , Microalgas/efeitos dos fármacos , Microalgas/química , OxirreduçãoRESUMO
Technological advancements have played a key role in improving energy efficiency and reducing emissions, and industrial robots are important carriers of intelligent manufacturing and industrial upgrading. Although various countries and regions are under pressure to reduce their carbon emissions, a consensus has not been reached on whether industrial robots can help. This study investigates how industrial robots affect carbon emissions by categorizing industry data from the International Federation of Robotics (IFR, 2010-2018) into city-level variables. The empirical finding revealed that cities' carbon emissions have been significantly reduced by the application of industrial robots. By using the penetration of robots in Chinese cities as an instrumental variable constructed through the combination of employment level and robot imports, the beneficial role of robots is further verified by a plausibly exogenous test. The mechanism analysis revealed that industrial robots contribute to cities' decarbonization by enhancing energy efficiency and green technology efficiency. The heterogeneity analysis showed that the effect of industrial robots on decarbonization is more pronounced in megacities, advanced manufacturing bases, and low-carbon pilot cities. This study empirically confirms the positive role of industrial robots in carbon emission reduction, provides evidence for industrial robots' technical characteristics of decarbonization, and proposes novel ideas for achieving net-zero carbon emissions.
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Robótica , Cidades , Carbono/análise , Dióxido de Carbono/análise , Indústrias , China , Desenvolvimento EconômicoRESUMO
Both the efficiency and capability of the seniority number truncated valence bond (VB) methods are highly improved by using our recently proposed extension of Malmqvist's algorithm for the reciprocal transformation of many-electron bases constructed by nonorthogonal orbitals [Zhou, Chen, and Wu, J. Chem. Phys. 149(4), 044111 (2018)] and by the adoption of the direct technique in solving the generalized eigenvalue problem. Due to the compactness of the wave function that benefited from seniority number restriction, the memory need and computational cost for energy evaluation and orbital optimization in valence bond self-consistent field calculation are largely reduced. The last obstacle in nonorthogonal orbital based ab initio VB calculation is thus removed. Consequently, we can accomplish seniority number truncated VB calculation at the same computational scaling as that of the most general configuration selected multiconfigurational self-consistent field with a memory cost much less than the corresponding complete active space self-consistent field (CASSCF). Test on Hn string molecules shows that the seniority number truncated VB calculation maintains the majority of static correlation by using a more compact wave function than CASSCF.
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Developing non radical systems for antibiotic degradation is crucial for addressing the inefficiency of conventional radical systems. In this study, novel magnetic-modified sludge biochar (MASBC) was synthesized to significantly enhance the oxidative degradation of sulfamethoxazole (SMX) by ferrate (Fe (VI)). In the Fe (VI)/MASBC system, 90.46% of SMX at a concentration of 10 µM and 49.34% of the total organic carbon (TOC) could be removed under optimal conditions of 100 µM of Fe (VI) and 0.40 g/L of MASBC within 10 min. Furthermore, the Fe (VI)/MASBC system was demonstrated with broad-spectrum removal capability towards sulfonamides in single or mixture. Quenching experiments, EPR analyses, and electrochemical experiments revealed that direct electron transfer (DET) and â¢O2- were mainly responsible for the removal of SMX, with functional groups (e.g., -OH, C=O) and Fe-O (redox of Fe (III)/Fe (II)) acting as the active sites. While the probe experiments showed that Fe (IV)/Fe (V) made a minor contribution to the degradation of SMX. Benefiting from the DET, the Fe (VI)/MASBC system exhibited a wide pH adaptation range (e.g., from 5.0 to 10.0) and strong anti-interference ability. The N atoms and their neighboring atoms in SMX were the prior degradation sites, with the cleavage of bond and ring opening. The degradation products showed low or non-toxicity according to ECOSAR program assessment. The removal of SMX remained within a reasonable range of 71.33% to 90.46% over five consecutive cycles. Also, the Fe (VI)/MASBC system was demonstrated to be effectively applied for successful SMX removal in various water matrices, including ultrapure water, tap water, lake water, Yangtze River water, and wastewater. Therefore, this study new insights into the mechanism of Fe (VI) oxidation and will contribute to the efficient treatment of organic pollutants.
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A novel approach of ball milling and oxalic acid was employed to modify sludge-based biochar (BOSBC) to boost its activation performance for peroxymonosulfate (PMS) towards efficient degradation of sulfamethoxazole (SMX). 98.6% of SMX was eliminated by PMS/BOSBC system within 60 min. Furthermore, PMS/BOSBC system was capable of maintaining high removal rates for SMX (>88.8%) in a wide pH range from 3 to 9, and displayed a high tolerance to background electrolytes including inorganic ions and humic acid (HA). Quenching experiments, electron paramagnetic resonance (EPR) analysis, in-situ Raman characterization and PMS decomposition experiments confirmed that the non-radicals of 1O2 and surface-bound radicals were the main contributors to SMX degradation by PMS/BOSBC system. The results of ecotoxicity assessment illustrated that all transformed products (TPs) generated in PMS/BOSBC system were less toxic than that of SMX. After five reuse cycles, PMS/BOSBC system still maintained a high removal rate for SMX (77.8%). Additionally, PMS/BOSBC system exhibited excellent degradation performance for SMX in various real waters (Yangtze River water (76.5%), lake water (74.1%), tap water (86.5%), and drinking water (98.1%)). Overall, this study provided novel insights on non-metal modification for sludge-based biochar and non-radical mechanism, and offered a feasible approach for municipal sludge disposal.
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Carvão Vegetal , Sulfametoxazol , Poluentes Químicos da Água , Sulfametoxazol/química , Esgotos , Ácido Oxálico , Poluentes Químicos da Água/química , Peróxidos/química , ÁguaRESUMO
This study aimed to design an efficient and easily collected/regenerated adsorbent for trace concentration sulfamethoxazole (SMX) removal to eliminate its negative impacts on human health, reduce the risk of adsorbed SMX release and boost the reusability of adsorbent. Various multiple modified sludge-derived biochars (SBC) were synthesized in this work and applied to adsorb trace level SMX. The results demonstrated that hydrothermal N-doping, magnetization coupled with ball milling co-functionalized SBC (BMNSBC) displayed the greater adsorption ability for SMX. The maximum adsorption capacity of BMNSBC for SMX calculated by Langmuir model was 1.02 × 105 µg/g, which was 12.9 times of SBC. Characterization combined with adsorption experiments (e.g., models fitting) and DFT calculation confirmed that π-π conjugation, Lewis acid-base, pore filling and Fe3O4 complexation were the primary forces driving SMX binding to BMNSBC. These diversified physicochemical forces contributed to the fine anti-interference of BMNSBC to background substances (e.g., inorganic compounds and organic matter) and its remarkable adsorption ability for SMX in diverse real waters. The great magnetization strength of BMNSBC was advantage for its collection and efficient regeneration by NaOH desorption. Additionally, BMNSBC exhibited an outstanding security in view of its low leaching levels of iron (Fe) and total nitrogen (TN). The multiple superiority of BMNSBC enable it to be a prospective material for emerging contaminants (e.g., SMX) purification, also offering a feasible disposal approach for municipal waste (e.g., sludge).
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A novel UV/oxalic acid functionalized corn straw biochar (OCBC)/peroxyacetic acid (PAA) system was built to degrade sulfadiazine from waters. 94.7 % of SDZ was removed within 30 min by UV/OCBC/PAA. The abundant surface functional groups and persistent free radicals (PFRs) on OCBC were responsible for these performances. Cyclic voltammetry (CV) and other characterization analysis revealed, under UV irradiation, the addition of OCBC served as electron donor, which might promote the reaction of electrons with PAA. The quenching and electron paramagnetic resonance (EPR) tests indicated that R-Oâ¢, 1O2 and â¢OH were generated. Theoretical calculations indicated sulfonamide bridge was vulnerable under the attacks of reactive species. In addition, high removal effect achieved by 5 reuse cycles and different real waters also suggested the sustainability of UV/OCBC/PAA. Overall, this study provided a feasible approach to remove SDZ with high mineralization efficiency, in addition to a potential strategy for resource utilization of corn straw.
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Carvão Vegetal , Ácido Oxálico , Ácido Peracético , Sulfadiazina , Raios Ultravioleta , Zea mays , Zea mays/química , Carvão Vegetal/química , Ácido Peracético/química , Sulfadiazina/química , Ácido Oxálico/química , Transporte de Elétrons , Poluentes Químicos da Água , Purificação da Água/métodosRESUMO
ABSTRACT: Background: As an immune marker, serum soluble programmed cell death ligand-1 (sPD-L1) is significantly increased in sepsis and is predictive of mortality. We investigated the prognostic value of sPD-L1 in postseptic immunosuppression and progression to chronic critical illness (CCI). Methods: Adults with sepsis in intensive care units (ICUs) for the first time were screened and assigned to either a CCI group (ICU stay ≥14 days with persistent organ dysfunction) or a rapid recovery (RAP) group based on clinical outcome. Data regarding basic admission information and clinical parameters were collected and compared across the two groups. Serum sPD-L1 levels were detected by enzyme-linked immunosorbent assay at admission and on the seventh day (D 7 ). Logistic regression analysis was used to determine the factors affecting septic patients' lymphocytopenia diagnosis on day 7 and CCI progression during hospitalization. The receiver operating characteristic curve and DeLong test were used to assess variable predictive power. Results: During the study period, a total of 166 septic patients were admitted to the ICU, and 91 septic patients were enrolled after screening. Compared with those in healthy individuals, the sPD-L1 levels in septic patients were significantly higher and positively correlated with traditional inflammatory markers and disease severity scores ( P < 0.05). In a multivariate regression analysis, sPD-L1 alone predicted lymphocytopenia on day 7 ( P < 0.05). In the sepsis cohort, 59 patients (64.8%) experienced RAP, and 32 patients (35.2%) developed CCI. Compared with the RAP group, the patients in the CCI group had a higher mean age, greater severity of disease, and higher mortality ( P < 0.05). D 7 -sPD-L1 remained higher in the CCI group, and the area under the curve that predicted the occurrence of CCI was equivalent to the APACHE II score, with areas under the curve of 0.782 and 0.708, respectively. Conclusions: The severity of infection and immunosuppression in sepsis may be linked to serum sPD-L1. D 7 -sPD-L1 is valuable in predicting the progression of CCI in patients.
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Linfopenia , Sepse , Adulto , Humanos , Estado Terminal , Ligantes , Prognóstico , Doença Crônica , Unidades de Terapia Intensiva , Apoptose , Curva ROC , Estudos RetrospectivosRESUMO
The clusters formed by modified materials on its surface makes the application of functionalized biochars in adsorption face a great challenge. Here, a facile ball milling technology was innovatively proposed to tailor Fe-Al oxides-laden bagasse biochar to fabricate a novel adsorbent (BMFA-BC). Benefited from the increased exposure of Fe-Al oxides and, more importantly, enhanced functional groups by ball milling, the adsorption capacity of BMFA-BC for aqueous tetracycline reached up to 116.6 mg g-1 at 298 K. And the adsorption performance was temperature-dependent. Characterization analysis, batch sorption (thermodynamics, kinetics, isotherms, chemical factors) as well as data modeling illustrated that this superior adsorption ability could be attributed to π-π conjugation, H-bonding, complexation as well as pore filling. BMFA-BC displayed good adsorption capacity in multiple aqueous environments. The excellent regeneration ability, magnetic susceptibility ensured its viability for sustainable pollutants removal. These superiorities revealed that BMFA-BC was a suitable sorbent for antibiotics elimination.
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Compostos Heterocíclicos , Poluentes Químicos da Água , Óxidos , Água , Adsorção , Antibacterianos/análise , Tetraciclina , Carvão Vegetal/química , Poluentes Químicos da Água/análise , CinéticaRESUMO
The battle against air pollution in China persists, and haze remains over cities. Whether industrial robots, as the core technology of intelligent manufacturing, can improve city air quality in the process of production has not been determined. Using the International Federation of Robotics data and Chinese city air pollution data (2013-2018), this study finds that industrial robots significantly reduce city air pollution levels (PM2.5, PM10, and SO2), which remains robust after addressing endogeneity. The mechanism of action lies in the synergistic benefits of industrial robots in reducing city air pollution levels by effectively improving energy use efficiency and promoting green technological innovation. Heterogeneity analysis suggests that industrial robots, as the incarnation of green technology, can be an effective alternative tool to green policies, such as low-carbon piloting, resource planning, and environmental regulation. This study empirically confirms that industrial robots are environment-friendly technologies that can provide new policy ideas to promote air pollution prevention and control in the industrialization process.