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Antibiotics removal and ARGs control in microbial fuel cell (MFC) has received extensive attention. In particular, the critical role of bioelectrochemical characteristics deserves further study. Bioelectrochemical characteristics significantly affected sulfamethoxazole (SMX) removal and ARGs fate, in which the current intensity played a more critical role than anode potential. High-concentration SMX (2 mg/L and 10 mg/L) facilitated the anode potential tend to be close, and thus, the strengthening effect of current on the system was highlighted. However, the SMX degradation pathway under different bioelectrochemical characteristics was not affected. Furthermore, the higher current intensity was preferable to antibiotic removal, but unfavorable for ARGs control might be due to the oxidative stress on microorganisms. Low-concentration SMX (0.5 mg/L) contributed to improving higher electricity generation because of Geobacter enrichement. This study suggested that appropriate bioelectrochemical characteristics regulation in MFCs was essential in removing antibiotics and controlling ARGs.

Abstract Organic solvent upgrading Indonesian lignite was performed in a 1 L autoclave under moderate temperature. The chemical structure and functional groups transformation of lignite upgraded by two organic solvents (ethanol and n-hexane) were analyzed to explore the upgrading mechanism of solvent thermal treatment by using Fourier transform infrared (FTIR) and 13 C nuclear magnetic resonance (NMR). In addition, the characteristics of pyrolysis of treated samples were investigated using thermo gravimetric (TG) to clarify the variance of pyrolysis reactivity. Results showed that the carbon content and calorific value of upgraded lignite were significantly improved, and H/C and O/C ratios of treated samples were significantly reduced with the temperature increasing. The relative percentage of carbonyl and carboxyl carbon, oxygenated aliphatic carbon and methoxyl carbon of lignite upgraded at 300 °C decreased by 20–30%. However, the carbon-substituted and protonated aromatic carbon at 120–135 ppm and protonated aromatic carbon at 90–120 ppm were significantly increased after lignite was upgraded by the two solvents at above 200 °C. These transformations indicated that oxygen-containing functional group was substituted by hydrogen or carbon-substituent as temperature increased, and were intensified at above 200 °C. In addition, oxygen-loss in the treated samples was attributed to the loss of carbonyl group at 175 ppm, dihydric phenol at 147 ppm, and methoxyl group at 55 ppm. The activation energy of upgraded lignite at 300 °C were higher than those of raw lignite and upgraded lignite at 100 and 200 °C, indicating the low reactivity of pyrolysis of the treated lignite with the temperature increasing.

AbstractAdsorption and desorption of Cu(II), Zn(II), Pb(II) and Cd(II) on a Red soil (RS, Udic Ferrosols) and a Wushan soil (WS, Anthrosol) amended with nanoscale hydroxyapatite (nano‐HAP) were studied by batch experiments. The adsorption isotherms show that different kinds of heavy metals had different affinity to the soils in the order of Cu(II) > Pb(II) > Cd(II) > Zn(II). The amount of each heavy metal adsorbed on the RS was lower than that on the WS, because the former had lower CEC and pH than the latter. The amendment of nano‐HAP in the soils significantly enhanced the adsorption of heavy metals, in comparison with the treatment receiving no nano‐HAP. The Kf, simulated from the adsorption isotherms, increased from 78 to 2180 for Cu(II), 16.6 to 59.5 for Zn(II), and 17.9 to174 for Cd(II) on the RS, and from 995 to 6410 for Cu(II), 52.5 to 92.4 for Zn(II), and 59.2 to 199 for Cd(II) on the WS, when 0.20 g nano‐HAP was added into 1.00 g soil. The nano‐HAP remarkably inhibited desorption of heavy metals from the soils, suggesting that the addition of nano‐HAP can significantly reduce the mobilization of heavy metals and increase their geochemical stability in metal contaminated soils. © 2009 American Institute of Chemical Engineers Environ Prog, 2010

Abstract Liquid air energy storage (LAES) is regarded as one of the most promising large-scale energy storage technologies due to its unique advantages of high energy storage density, no geographical constraints and long life-span. The LAES mainly includes air liquefaction (charging cycle) at off-peak time and power generation (discharging cycle) at peak time. During air liquefaction, ambient air is first required to remove its compositions with high freezing points (H2O and CO2) before it is cooled down (denoted as air purification process), preventing pipeline blockage and guaranteeing safe operation. However, most of previous studies simply neglected the air purification process and assumed ambient air was already purified. This may cause overestimation of the LAES performance as the air purification process usually consumes thermal energy or electricity. To address this issue, this paper proposes a novel LAES system with energy-efficient air purification. Dynamic characteristics of the air purification process are investigated from molecular to systematic modeling for the first time. Simulation results show that the air purification process could be driven by exhaust air from the air turbine at peak time rather than thermal energy or electricity in the traditional methods. This could improve the electrical round trip efficiency by 2.3% compared with the traditional methods. In addition, the proposed LAES system shows a combined heat and power efficiency of 82.5-86.7%, an electrical round trip efficiency of 47.9-59.6% and an exergy efficiency of 58.4-68%. These findings will be helpful to understand the function of air purification in the LAES system, providing guidelines for practical applications.

This communication is motivated by recent publications discussing the affordability of appropriate decentralized solutions for safe drinking water provision in low-income communities. There is a huge contrast between the costs of presented technologies, which vary by a factor of up to 12. For example, for the production of 2000 L/d of treated drinking water, the costs vary between about 1500 and 12,000 Euro. A closer look at the technologies reveals that expensive technologies use imported manufactured components or devices that cannot yet be locally produced. In the battle to achieve the United Nations Sustainable Development Goal for safe drinking water (SDG 6.1), such technologies should be, at best, considered as bridging solutions. For a sustainable self-reliance in safe drinking water supply, do-it-yourself (DIY) systems should be popularized. These DIY technologies include biochar and metallic iron (Fe0) based systems. These relevant technologies should then be further improved through internal processes.

To reduce fine particulate matter emission from coal burning sources especially fossil fuel fired energy generation facility is critical to improve air quality. Attapulgite suspension was attempted to spray in a 6 kW fluidized bed facility and reduce fine particulate matter emission during coal combustion. The key parameters such as attapulgite mass, flowrate and spraying zone were investigated to determine the optimal and critical conditions that influence fine particulate matter emission. Exciting results indicate that both fine particle number and mass concentrations are largely decreased due to the physical/chemical absorption with the suitable mass ratio of 3 wt%. The spray of attapulgite suspension in both dense bed and dilute bed effectively mitigates fine particle emission based on the agglomeration and absorption. The most excellent result is achieved at a flowrate of 38 ml/min in dense bed with particle number reduction up to 93.5% in PM2.5 (fine particles is equal to/less than 2.5 μm), 93.6% in PM1.0 (fine particles is equal to/less than 1.0 μm) and 93.7% in PM0.1 (fine particles is equal to/less than 0.1 μm), respectively. The work highlights the potential of spraying attapulgite suspension as an effective process to reduce fine particle emission during coal combustion in fluidized bed system.

Purification is a separated post-treatment step after the synthesis of nanocrystals (NCs) in order to exclude excess ligands and monomers in NC solution. The common purification process involves many manipulations, such as concentrating, addition of anti-solvents and centrifugation, which are troublesome and time consuming. In this work, we originally integrate NC synthesis and NC purification in one-pot via selecting water-ethanol co-environment for NC synthesis and NC purification. Our research shows that NCs can grow in water-ethanol mixture. When growing into critical size, NCs will automatically precipitate from the solution. Element analysis demonstrates that precipitates fraction fits well with stoichiometric of ligand-capped NCs. Excess monomers are left in supernatant, and thus achieving automatically purification of NCs in the water-ethanol co-environment. By adjusting the volume ratios of water and ethanol in bi-solvent system, different-sized purified NCs can be controlled. Besides, this water-ethanol co-environment can be used in both thermal-promoted and hydrazine-promoted growth.

The pyrolysis of sewage sludge (SS) in the presence of sewage sludge pyrolysis char (SSC) as catalyst was conduct in a horizontal reactor at 500°C. Gas chromatography-mass spectroscopy (GC-MS), element analysis, high heating value (HHV) analysis, water content analysis and gel permeation chromatography (GPC) were used to characterize the pyrolysis oil. The declined char yields with increased SSC mix ratio (MR) indicated that SSC could promote the devolatilization reaction. Meanwhile the declined top phase oil (TPO) yield and increased bottom phase oil (BPO) and gas yield showed that crack reaction may happen catalyzed by SSC. According to the result of GC-MS, aliphatics and steroids content drops apparently since MR increased to 50 wt.%, while aromatic compounds and phenols content increased at the same time. Element analysis showed an apparent transportation of hydrogen and oxygen from TPO to BPO. HHV of TPO decreased with MR increased. The result of GPC indicated that increased MR caused continuing decreased average molecular weight of TPO. Consequently, the increased SSC addition could promote the devolatilization and large molecular compounds catalysis crack of sewage sludge.

Abstract In this study, a solar-driven reduction process of nonstoichiometric cerium oxide in a fixed bed is optimized for efficient water splitting via metal-oxide-based redox cycling. Nitrogen is used as sweeping gas to scavenge oxygen from the beds during the reduction process. A transient lumped heat transfer model is developed for the simulation of the process. Parametric analysis and genetic algorithm are used to find the optimal N2 flow rate and establish a novel N2 feeding strategy with variable flow to maximize the thermal efficiency for water splitting. An efficiency close to 13% is estimated without solid-phase heat recovery, which is more than twice that of the best present experimental systems (∼5%). The results are regarded preliminary as a thermodynamic analysis.